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BABY PEAS (Pulse Early Alarm Sensor)

1. 9 Owlet Baby Care The Wireless IPhone Baby Breathing Monitor Owlet Baby Monitors N p n d Web 30 Nov 2013 lt http www owletcare com gt 10 Snuza Halo Baby Movement Monitor Amazon com Baby N p n d Web 30 Nov 2013 lt http www amazon com Snuza Halo Baby Movement Monitor dp BOO2ITOC7S gt 11 Team KnightTime N p n d Web 30 Nov 2013 lt hitp www eecs ucf edu seniordesign fa2012sp2013 g01 gt 128 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Neligan Patrick How Do Pulse Oximeters Work All about Oxygen N p 2002 Web 30 Nov 2013 lt http www ccmtutorials com rs oxygen page17 htm gt Tilakaratna Prasanna How Pulse Oximeters Work Explained Simply Anesthesia Equipment Simplified and Explained For Anaesthesiology FRCA Physics Anaesthesia Staff Nurse Anesthetist CRNA Anesthesiology Board HowEquipmentWorks com How Pulse Oximeters Work Explained Simply Anesthesia Equipment Simplified and Explained For Anaesthesiology FRCA Physics Anaesthesia Staff Nurse Anesthetist CRNA Anesthesiology Board HowEquipmentWorks com N p n d Web 30 Nov 2013 lt http www howequipmentworks com physics respi_measurements oxygen ox1 meter pulse_oximeter html gt Ayala Kenneth J The 8051 Microcontroller Architecture Programming and Applications St Paul West 1991 Print Applicatio
2. Using a Spectrum Analyzer and RF probe check RF_N pin during transmit TX Power Mode set to 0X91 Using a Spectrum Analyzer and RF probe check RF_N pin during transmit TXPower Mode set to 0x41 Using a Spectrum Analyzer and RF probe check RF_N pin during transmit TX Power Mode set to 0X41 Use an O scope to measure 32MHz crystal oscillator Use an O scope to measure 32 768 kHz crystal oscillator This test will look at the gain flatness over the operating frequency band to verify the CC2541 is properly transmitting This test will look at the gain flatness over the operating frequency band to verify the CC2541 is properly transmitting This test will look at the gain flatness over the operating frequency band to verify the CC2541 is properly transmitting This test will look at the gain flatness over the operating frequency band to verify the CC2541 is properly transmitting This test will look at the gain flatness over the operating frequency band to verify the CC2541 is properly transmitting This test will look at the gain flatness over the operating frequency band to verify the CC2541 is properly transmitting Verifies a proper 32 MHz stable oscillator frequency is present Verifies a proper 32 768 kHz stable oscillator frequency is present Gain flatness should be 1dB over frequency band with an output power of 0dB Gain flatness should be 1dB over frequency band with an output power of OdB G
3. Dropout Voltage mV 150 100 4 50 04 0 20 40 60 80 100 120 Output Current mA L Figure 23 Typical Dropout Voltage approximation diagram for LT1761 Created by Xin Tong in MS Excel The quiescent current is at 20uA and comes in a static voltage select package In addition throughout the course of usage the quiescent is controlled to near 20uA 57 ee TS LT1761ES5 2 5 Co 1OpF Figure 24 Typical Application for LT1761 Created by Xin Tong in NImultisim 3 3 8 4 2 Switching Regulators Texas Instruments TPS62740 The second option for power regulation is switching or switched mode power supply In this case the power supply is switched on and off in a swift pace outputting an average supply voltage The switching regulator such as the one shown in Figure 24 control the gate using a certain frequency The amount of power going through is determined by the amount of time the switch is closed The output voltage depends on how much voltage is at Vin and the switch duty cycle Figure 25 Simplified Switching Regulator Created by Xin Tong in NImultisim The controlling gate of the switching regulator is usually a transistor or a thyristor In addition extra components are needed to make a circuit function as a useful power supply Rectifying diodes and inductors help the output capacitor with providing a steady ripple free output Figure 25 shows one such configuration Because ther
4. Integrate into existing eas H and test Repeat test matrix SW Milestone 3 comp TR S O O NE ME E Table 40 Software Tasks Milestones Chart Senior Design 1 Software tasks are designed with two main hurdles to cross a working code with the sensor tag and working code with the designed PCB The first hurdle can be crossed without the hardware component integration TI s CC2541 developmental sensor tag is 123 designed specifically for developers to write applications Using that tag the project can get a working code in order before the PCB boards are populated sensors integrated and tested A sensor tag was ordered on 11 12 2013 and is currently in the project s stock The only hurdle from current development at the time of writing is an updated android device but the project stock is expected to be in the recipient of a working android device by 1 1 14 Once the device is in hand a period of two weeks is given to developing working code for Bluetooth handshake temperature and accelerometer Unfortunately the sensor tag lacks a pulse module so instead of a working code the goal is to have a code that will be tested once the module for the pulse is integrated into the hardware board Starting week 9 the hardware side should have an assembled board along with a week of preliminary testing This is to insure that all power parameters are functioning and the board won t be irreparably harmed once the testing phase is moved to a
5. It would be fine for you to use this image free of charge providing that the website is acknowledged Please use the wording This image has been reproduced from AnaesthesiaUK with permission www AnaesthesiaUK com Good luck with your paper With kind regards Adrienne Dr Adrienne Penfield AnaesthesiaUK From yow wu lin mailto wasiasd hotmail com Sent 25 November 2013 19 14 To adrienne frca co uk Subject RE AnaesthesiaUK Web Site Feedback Hello Adrienne Thank you for replying The particular information need is in this weblink http www frca co uk article aspx articleid 100345 I m using it as a reference for my school paper and may use the oxygen dissociation curve graph for the paper It will include the mark for AnaesthesiaUK and any citation will be done properly Thank you so much Sincerely Yowwu Lin gt From adrienne frca co uk gt To wasiasd hotmail com gt Subject RE AnaesthesiaUK Web Site Feedback gt Date Mon 25 Nov 2013 08 12 31 0000 gt gt Hi gt gt Please send a link to the web page you are referring to and we will then be gt able to tell you if we can grant permission gt gt Kind regards gt 136 gt Adrienne gt gt gt gt Dr Adrienne Penfield gt AnaesthesiaUK gt From wasiasd hotmail com mailto wasiasd hotmail com gt Sent 23 November 2013 04 00 gt To sumit frca co uk adrienne frca co uk ray frca co uk luk
6. cccoooooonnncnnnnncnnnnnnno TA Ale Electrical haracteristiCS a 78 4 1 4 2 2 Current Consumption with TPS62730 oooooonnncncnnncccnnnnnccnnnnnnnnnos 78 A 2D General hartactenisti Sad 78 Ato CECE24L Block DIastaM nessa 79 ddA CPUE Menor usina 79 ANAS SREP PACRANS pesei aea e e eesi 80 4 1 4 6 Application information CC2S4 1 ooooonncnnnccccnnnnnoccnnnnnnnnnononnnnnnnnnnononanos 83 A M4 Oul POW er CONT CUA OR a 83 4 1 4 6 2 SPI bus AC Characteristics of CC24Al ooooooconcccnononononononocnnnnnnnnnos 84 ANAC A laa 87 A 88 414641 Serial Data Input QUtPU iaa ds 89 4 1 4 7 Microcontroller Coding SO tWAre ooocccccccccconononnnnnnnnnnnnnnncnncnnnnnnnonanos 91 ALAS Debuecing Feature COLA ea 95 4149 CC254ideDug CE VICO dlia 97 AS ser interlace Destinia laa 98 Bled Fou ISroo 8 OP ROO PO PO a O 99 AOL Restive TOLUCA nai anios 99 AW ee ASAD ACI Ve TOLUCA ao ia 101 AMD Touch Screen Kits fins cencastnicicansracsandunsaaaeehniezeoresszermnsesad a 101 415 2 Software Development sv coon Sew a net weanenns 101 A Sowas dagta aid 102 Alcea Cas Caer AN eaga ms ssisata eats 103 AAG Bluetooth Handshakeu sa aaa 103 4 1 6 1 Android Platform for Classic Bluetooth cccccccconononcccnnnnnnnnos 103 4 1 6 1 1 Setting up the Bluetooth device ss ssori an 104 Alok pearchio Torother device ile 104 4 1 6 1 3 Connecting device as Server Side oooncccccccccononoccnnnnnnnnnnnnnnnnnnnnnnnos 105 A NOW Manace a CONE CHO aracia 107
7. d tan 75 d distance to surface r radius of field of view The formula is shown above if we want to find the distance we plug in r centimeter we find the distance is 0 27centimeter or 2 7mm To eliminate the infrared source signals from ambient sources a metal shield could be used or place the sensor within the calculated distance Creating a metal shield for such size would be somewhat unrealistic in this project using appropriate distance can be easily achieved As shown in Figure 16 over 90 of the IR signals are from the target object if the distance is less than half of the desired radius 42 Tt Yields gt 90 lt 2 Signal Percent of TMP006 Signal from Target Object 9 0 0 5 1 1 5 2 Distance d Object Radius r Figure 16 TMP006 Temperature sensor operational distance diagram Reprinted without alteration with permission by Texas Instruments To correctly calculate the temperature of an object it is best to keep TMP006 from the rest components on the system Heat from the PCB that TMP006 lays on may interfere with temperature calculation as well A series of mathematical formulas are used for calculation and are discussed shortly The TMP006 suggested PCB layout can be seen in figure 17 It is a guideline created and tested by Texas Instruments for optimal performance The design 1s a two layer PCB For Baby Peas project 1t will be more than two layers 300mil 8x 6mil Traces 300
8. s OSHA rated personal protection equipment such as goggles hard hats gloves face shields and clothing which all cost a considerable amount it is foolhardy to build an AC power supply It is recommended to buy an off the shelf AC power unit for this project 3 2 9 3 DC Power DC to DC power supply is used in two aspects recharging the unit via solar power and supplying power to the different modules in the unit 3 2 9 3 1 Solar Power A generic solar power unit consists of the Photovoltaic cells the combiner inverter and storage unit The inverter is used to turn the solar generated DC power into AC as most of the solar units are used to supplement mains power If the baby peas unit is charged via solar power this inverter step 1s not needed Photovoltaic cells basically work under the principle of the photoelectric effect of some materials As photons strike the surface energy 1s collected and transformed into a current Figure 6 shows a simple set up of the process 28 Sunlight YL LAL uy Specially Treated rr E Material s Back Contact Figure 6 A basic photovoltaic cell operation diagram created by Xin Tong in MSword Using a number of cells in modules and set in arrays a multitude of these cells can harvest a considerable amount of power from the Sun Amorphous photovoltaic cells would be the cheapest options but is the least efficient and have the least lifespan Both Monocrystalline and polycrystalline are
9. 3 Research Related to Project 3 1 Existing or Similar Project and Products 3 1 1 www owletcare com Owlet Baby Monitor was developed by six students from Brigham Young University and won the first prize of Student Innovator of The Year in 2012 Tanor Hodges who works at University of Utah Hospital came up the idea with his friend Kurt Workman who is a chemical engineering student Student Innovator of the Year SIOY is a competition for Brigham Young University for developing and encouraging students with new ideas products with technology and engineering It is sponsored jointly by the Ira A Fulton College of Engineering and Technology and the Rollins Center for Entrepreneurship and Technology at the Marriott School The sensor is incorporated in the Smart Sock which is worn by babies It 1s capable of measuring heart rate pulse oximetry temperature and body position The main motivation for the project was to combat SIDS Sudden Infant Death Syndrome The data collected by the sensors are transmitted to parents smart phones and the cloud which is accessible via any devices with internet connection The main transmission method from the portable sensors to the mobile phones is via Bluetooth 4 0 The battery life is unknown but it is rechargeable Notifications will be sent out when the batteries are running low The Bluetooth is set at 2 4 GHz so that it would not interference with other cell phones home alarms and other electronics Apple
10. Acid base balance of the body is regulated via respiration as well Arterial blood sample is drawn and analyzed if respiration pattern or effort is compromised Just like heart rate respiration rate can rise when illness is present In a healthy baby the respiration rate is about 35 and up to 70 with excitation If respiration rate drops below normal and the baby appears to be lethargic the parents should seek emergency medical attention In conclusion it 1s important to monitor the babies regularly to prevent tragedy from occurring and provides a peace of mind for the parent In Table 2 a summarized chart compares newborns infants toddlers and adults for their normal vital signs Please note the vitals are for health individuals without congenital disorders Certain diseases or health issues may alter the norm of each individual The Baby Peas project aims to provide easy convenient and safe ways to monitor babies Utilizing low power consumption components heat generation is reduced to minimum With high quality sensors we maximize the accuracy to ensure the safety of the babies 10 Heart rate Oxygen Respiration Blood Sleep Time Beat per Level Respiration Pressure per minute Percentage per minute mmHG Newborn 90 170 gt 95 35 70 84 52 E Hours 1 2mo Infant 90 170 gt 95 25 70 84 52 3 11mo om _ Toddler me 160 uw os 35 84 52 12 14 1 3y er a ys om 7 a o Table 2 Vital Signs Chart Summary 3
11. This puts it into the not addressed slave state When the CC2541 is put into sleep mode Power mode 2 or Power mode 3 it resets the I C module The module must then be reconfigured when coming out of sleep mode The master device initiates data transfer when the start condition is present This occurs when the SDA falls from high to low and the SCL is high The stop condition occurs when the SDA rises from low to high and the SCL is high The stop condition is necessary to cut off the transmission of data The SDA bit must be stable during the high period of the SCL The SDA can only change during data transmission while the SCL is low to avoid a mistaken start or stop condition Another start condition during data transfer is referred to as a restart The slave address is once again sent with the R W bit This is used to switch data directions Data is transferred MSB first The 87 first byte of data transferred is the 7 bit slave address and the R W bit The R W bit determined if the master is outputting data or inputting data The R W bit is low when transmitting data to the slave device The R W bit is high when receiving data from the slave The acknowledgment bit ACK is sent from the receiver after each byte on the ninth SCL clock Figure 55 illustrates the IC data transfer procedure m m y SDA XXX S S VX XG Y MSB Acknowledgement Acknowledgement Jo Signal From Receiver Signal From Receiver SCL TINO SIN IN IN
12. and low cost While there are numerous components which offer Bluetooth technology priority will be given to components which consume the least amount of battery power while in standby and transmit modes 47 3 3 6 1 CC2541 BLE SOC The CC2541 is a system of chip SoC which conforms to the Bluetooth Low Energy standards but also has a built in microcontroller embedded within the chip itself It is designed by Texas instruments It contains 5 different power modes which are available in table 12 Table 13 Power Modes CC2541 BLE RF module The CC2541 is suited for ultralow power consumption systems Its transmit frequency ranges from 2379 2496 MHz and boasts four different data rates 2 Mbps 1Mbps SOOMpbs and 250 Mbps The receiver sensitivity is 1Mbps high gain mode is 94dBm and a BER of less than 1 at 5dBm The CC2451 also feature a unique in band blocking technology which aids in keeping unwanted signals in the 2 4 GHz range from interfering with the transceiver There is also no need for an output gain stage to boost the range of the transceiver A development kit CC2541EMK made by Texas Instruments can be purchased to quickly bring the project up to speed on the design and implementation of this device into the baby peas project The CC2541 has a high performance industry stand 8051 microcontroller imbedded onto the chip itself This portion of the CC2541 is covered in the microcontroller section The chip comes in a 6mm x 6
13. and rather safe On the down side it is quite inaccurate 3 Causes for temperature spikes and ways to measure accurately e Infections dehydration and physical surroundings e Most accurate measurement is rectally e Most noninvasive is through armpit Temperature is a vital sign that the caretaker needs to know in order to ensure the safety and health of the baby Baby Peas can help with monitoring temperature accuracy may be a trade off for convenience As mentioned above using a rectal thermometer is the most accurate but also the most invasive Measuring the armpit while not as accurate 1s the least invasive The danger of temperature is not necessarily in the minute degree differences but rather in spikes or unusual declines Using a temperature sensor that can be attached to ankle and wrapped with a sock seems reasonable as long as the normal general temperature in the certain area is taken into consideration Knowing the long term trend of the baby s temperature tells more about the wellbeing of the baby rather than single point data 3 2 1 3 2 Blood Oxygen Levels Blood oxygen is an important part of vital signs The cells in our bodies consume oxygen and nutrients to maintain their functions Depending on the environment and activities saturation of oxygen level may change There are two ways oxygen is transported in blood vessels The majority of oxygen is bonded to hemoglobin on the red blood cell A red blood cell has four heme
14. tmp mBluetoothAdapter listenUsingRicommWithServiceRecord NAME MY UUID catch IOException e mmServerSocket tmp public void run BluetoothSocket socket null ff Keep listening until exception occurs or a socket is returned while true try socket mumServerSocket accept catch IOException e break If a connection was accepted if socket null Do work to manage the connection in a separate thread manageConnectedSocket socket mmServerSocket close break Will cancel the listening socket and cause the thread to finish public void cancel try mmServerSocket close catch IOException e Figure 70 Example code for Android Bluetooth Connections reprinted without alteration and with permission from Android 106 4 1 6 1 4 Managing a connection Once connection is made the devices exchange data via InputStream OutputStream read byte and write byte calls 4 1 6 1 5 Profiles Android offers several Bluetooth profiles Headset A2DP and Health Device Headset is a profile for using wireless headsets via interprocess communication a method for exchanging data through many threads A2DP stands for Advanced Audio Distribution Profile and it controls the audio quality coming in from the wireless device The project is concerned primarily with the Health Device profile With this profile the Android device can exchange information with health moni
15. 2 2 Pulse Oximetry Sensors As discussed previously blood oxygen level is measured by a device called pulse oximeter Two light emitting diodes are required to differentiate the oxygenated red blood cells from deoxygenated ones The light travels through the skin and hit the light sensitive detector on the other side There are two main light waves to be considered One is at 660 nm red light and the other at 940 nm infrared The oxygenated red blood cell absorbs the light source with longer wave length 940 nm while the deoxygenated red blood cell absorbs 660 nm As seen in the Figure 2 below absorbance of wavelength is subjected to the red blood cells with or without oxygen 12 absorbance 650 nm 800 nm 950 nm Red pare wave length MiSS S Figure 2 Absorbance vs wavelength diagram Diagram reprinted via permission from diagram designer Pras at Pras2 onvenus com Majority of the light does not reach the light detector due to light absorption by the skin tissue and bones The amount of the light at the receiver site is actually around 2 of the 11 total emitted By comparing the amount of light being absorbed at different wavelengths a ratio can be calculated The ratio signifies total amount of oxygenated hemoglobin compared to total hemoglobin In Figure 3 75 is shown based on absorption of infrared light is 75 percent compared to the amount absorbed in red light The mathematical equation for measurement lo A R Place
16. 202 R lograc 42 Ax the wavelength of 660nm gt the wavelength of 940nm the current from analog front sensor R ratio used from Figure 4 SaO oxygen saturation Ratio absorbance 650 nm 800 nm 950 nm Red Inf ed lia ht wave length ioni Figure 3 Light Absorption ratio Diagram reprinted via permission from diagram designer Pras at Pras20 onvenus com Note that there are factors which might alter the trustworthiness of final calculations Methemoglobin and carboxyhemoglobin absorbs light in a different wavelength and is not being calculated in a typical pulse oximeter CO oximeter is needed for such circumstance which requires a different design which will not be used in the Baby Peas project The formula below shows the overall oxygen saturation percentage 12 100 HbO ak Hb HbO HbCO METH nhemoglobin Hb all hemoglobin HbO2 hemoglobin binds to oxygen HbCO Carboxyhemoglobin METHb Methemoglobin Nhemoglobin non functioning hemoglobin Since only the oxygenated blood is needed for calculation the change in the signal is used Filtering out the non changing signal using complex mathematical manipulation the remaining data represents the pulsating arterial blood hence the name pulse oximetry 100 Y gt 80 9 5 60 Beer Lambert 5 Model w gy 40 Empirical 20 Calibration gt lt O 0 0 5 1 0 1 9 2 0 2 5 Ratio R Figure 4 Oxygen Saturation Rati
17. 3 axis accelerometer measurements along with 3 axis gyroscope measurements The chip is also scalable in it provides a dedicated IC bus to accept an external 3 axis magnometer which would give 9 axis data measurements Range of the accelerometer portion consists of 2g 4g 8g 16g which are user programmable which means if only 4g range is needed it can be selected and reduce the amount of current the IC would draw They gyroscope range is selectable as well consisting of 250 degrees per second dps 500 1000 2000 dps The chip also consists of 6 16bit analog to digital converters ADCs to sample all axis points of both the accelerometer and gyroscope It boasts an onboard 1024 byte FIFO which allows for the microcontroller interfaced with it to read data output from the MPU 60x0 series in bursts This allows the microcontroller to go into a sleep mode while the MPU collects more samples The output of the MPU is digital and compatible with both SPI and I C MPU 6050 only uses IC IC data rates are up to 400kHz and SPI data rates are up to 1MHz The input voltage to the chip is between 2 375v 3 46v which is in the boundaries of usable input voltage for this project Price is around 10 dollars if purchased through Digikey with a lead time of around 2 3 weeks The MPU also has an additional temperature sensor on the device but this most likely will not be used since another sensor being used in this project will take
18. AS A atchure in dvens tect wed oheeiracsioen 107 5 Project Prototype Construction and Coding oooooocncnnnnnnnnnnnnnonnnnnnnnnnnnnnannnnnnnnnnnnnnnnos 107 5 1 Parts Ac quisition and BOM il iia 107 Dll Part MENOS ida 107 I A E o O ae ess cee 107 E 3 Cos eee ene ee ee er een seen ene ee eee eR E IN 107 5 1 2 2 Sparkfun and local hobby centers oocccccooononcnccnnnnonononocnnnnnnnnnos 108 5 1 2 3 Price list of Hardware BOM Development Tools 108 22 REB Vendor and Assembly arien Rua staat ales 109 5 2 PCB Vendor cede ree aside al oa reid chee 109 SaL oo bee FP E 109 S212 PEB FaDexpreS Seci wcasiedeatareieukindeae nite 109 ILS Custom Cucut Board S eer dao 109 liz POCBASssembDIy HOUSES ier a 110 5 2 2 1 QMS Quality Manufacturing Solutions oooooncccnnnccnnnnnnnnnnnnnnnnnos 110 DZ Died CONNEC erede e a E des 110 32293 DIY Domt yours icons 110 Os Project Prototype Tesino anisa idad 111 6 1 Hardware Prototype POS cui A neuetaaniaceets 111 6 1 1 Battery Regulator and Charging Circuits ccccccnnnnnonocccnnnnnnnnnnnanannnnnnnnnoos 111 6 1 1 1 Temperature Sensor Hard Ware ccccoooooocnccnnnnnnnnnnnnonnnnnnnnnonanananacnnnnnos 112 6 1 1 2 Body Position Sensor Hardware ccoooooonnccnnnnnncnnnnnnnnnnnnnnnonananocannnnnns 113 6 1 1 3 Pulse Oxametry Sensor Hard Wario 113 6 1 2 Wireless Communications Hardware Test ooooooonnnnnnnnnnnncnnnnonnnnnnnnnnnos 113 6 2 SOllware
19. At 20 dBm the current consumption is typically 16 8 mA 4 1 4 2 2 Current Consumption with TPS62730 In RX mode standard mode with no peripherals added and low MCU activity at 1 MHz the current consumption is 14 7 mA In RX mode and high gain mode keeping everything else the same the current consumption is 16 7 mA In TX mode at 20 dBm output power with no peripherals active and low MCU activity at 1MHz the current consumption is 13 1 mA In TX mode at 0 dBm keeping everything else constant the current consumption is 14 3 mA The current used in both transmit and receive modes are relatively small It follows that the larger the signal the more power is required to power the device 4 1 4 2 3 General Characteristics The wake up and timing characteristics are as follows Power 1 means the digital regulator is on and the 16 MHz RCOSC and 32 MHz crystal oscillator is off The start up of the 16 MHz RCOSC to active mode takes 4 us In Power mode 2 or 3 the digital regulator 16 MHz RCOSC and 32 MHz crystal oscillator are off The start up of the regulator and 16 MHz RCOSC to active mode takes 120 us The timing of active mode to TX or RX are as follows with the 16 MHz RCOSC on and 32 MHz XOSC off 500 us with the 32 MHz XOSC initially on 180 us 78 4 1 4 3 CC2541 Block Diagram Modules can be divided into three categories CPU related modules Power test and clock distribution radio related modules The CPU related modules refer
20. Prototype Testi a 114 621 ECG2IA Sotware Testo aia ias 115 6 2 2 User Interface Module Software Test ooccccccccccoonnooccnnnnnnnnonanannnnnnnnnnos 115 6 3 System Level Testa e 116 63 1 Skin Temperature Final Tesi ii A 117 0 02 Body position Pinal Testa iaa erica 117 03 Pulses ximetry Pinal Lestat pi 118 6 3 4 Weight Battery Life and Wireless Range Final Test ooocccccnc 119 7 PRAMAS ERAT VS COMO EE 120 7 1 Milestones and Schedule DISCUSSION ccccccccccononccncnnnnnnnnnocnnnnnnnnnnnnnnannnnnnnnnnos 120 hi2 Rosand RESPONSES a sian teutnemwinltn ean A tiecamiceaiaes 124 7 3 Budset and Finance Discussion ii 125 TA U NIA acre ar cette O 125 7 5 SE A A En NE 127 S APpehlicE Sails 128 8 1 Appendix A RETETE NCES aaa a 128 8 2 Appendix B Copyright Permissions cccccccccccccccessseseceeeeeeeaeeeeeeeeeeeeeeeaas 132 1 Executive Summary Despite being a successful species at large humanity starts off life as a weak and wholly dependent creature with little capacity for communications or self awareness An infant requires 24 hours of careful supervision a daunting task in today s busy world on a good day and a seemingly impossible task on a normal day The Baby peas unit seeks to take some of the burden from the shoulders of the caretaker giving him or her ability to multitask and accomplish chores around the house or take a brief moment of watchful relaxation While not intended as a fully
21. While 1 C is not a big difference in many applications but that is not the case for monitoring body temperature Baby Peas strives to provide safe and accurate measurement Further testing will be done to ensure TMP103 qualifies the specification required by Baby Peas Monitor 46 eto D 4 l PIN A1 INDEX AREA gt G0 015 CA B 0 12 puna 0 625 MAX Y J o SEATING PLANE D Max 0 79 mm Min 0 73 mm E Max 0 79 mm Min 0 73 mm 4207625 2 AN 07 13 Figure 19 Package Dimension of Texas Instruments TMP103 Reprinted without alteration as allowed by Texas Instruments Knowing the dimension of wafer chip is essential for successful PCB layout The maximum and minimum length is given in Figure 19 Cadsoft Eagle was used to create schematic diagram and the package dimension was taken into account 3 3 6 Communications Sensor The Baby Peas communications design will be built around using Bluetooth technology Wireless communications is key to the success of this project The wireless module will be implemented on the Baby Peas sensor The wireless module will except data from the microcontroller and convert the data to RF which will be sent to a device with the ability to receive a signal via the Bluetooth standard Considerations while choosing a particular component to implement will be low power consumption output transmit power receiver sensitivity BIT error rate ease of implementation ease of soldering
22. a function generator to simulate the widest array of loads possible to make sure our regulator stability loop is critically damped and not ringing Once the stability of the regulator is within specifications the remaining components will be soldered into place The Micro Controller will then be loaded with the latest software and then testing of each sensor will occur It s expected this process could take up to 5 weeks or more to complete Once each device is working properly and wireless communications is established with mobile user interface module then the project hardware is complete The baby peas project has left room starting in the last week in February to try and complete a polished prototype PCB consisting of no white wires If time permits it is the goal to redesign the PCB to a smaller package for an infant repopulate the PCB retest and be able to present our polished design project for the final presentation 16 Dec 30 Dec 13 Jan 27 Jan 10 Feb 24 Feb 10 Mar 24 Mar 7 Apr 21 Apr Software Tasks W1 2 W3 4 W5 6 W7 8 W9 10 W11 12 W13 14 W15 16 W17 18 W19 20 Review Java TI Sensor tag interface with existing code User Interface design Notification algorithim Graphing libraries TI Sensor tag interface with new code Integrate code with hardware Test Temperature Sensor Test Position Sensor Test Pulse Oximetry Sensor Test RF performance es EES code SW Milestone 2 comp Utilities portion design Editor and Email
23. and a minimum sampling rate of 8 bits of resolution The microcontroller will also interface with a Bluetooth wireless system and thus must have both SPI and I C in order to have the flexibility to integrate sensors into the system 3 2 9 Power The power supplied for this project come from two sources alternating current from the main electrical grid and direct current from battery or power supplies such as those in a PC connected through a USB In addition to the two types of power source the unit also uses linear or switching regulator integrated chips to help provide steady power to the modules on the satellite unit 22 3 2 9 1 Power Considerations and Safety There are a number of considerations to be made for the power subsystem As integrated components shrink and get more efficient one of the most important decisions that decide the final product and packaging is power In order to provide the needed functional length and reliability the power subsystem tends to take up the majority of space and weight in the product x For this project in particular the sock unit needs to be lightweight It would be onerous and maybe even dangerous for a baby to be wearing anything to heavy In addition since this unit is being used to monitor health effects the power source chosen cannot have weak points in its delivery system or longevity Providing a seamless experience for the user requires attention to safety measures efficient usage of po
24. atrium right ventricle left atrium and left ventricle In systemic circulation blood is pumped out from left ventricle through aortic valve three leaflets to the aorta during systole From the arteries blood is delivered to the tissues in the capillaries where gases and nutrients exchange occur The deoxygenated blood moves to the vein and returns to the heart in the right atrium From the right atrium it moves to the right ventricle thru tricuspid valves During heart muscle contraction the blood is pumped to the lungs via pulmonary artery Once the blood reaches to the lungs the oxygen and carbon dioxide exchanges take place and oxygenated blood is carried to the heart thru pulmonary veins The left atrium receives the blood and transports the blood to the left ventricle through mitral valves during diastole The heart perfuse itself during diastole phase when the aortic valves close and blood goes through sinus of Valsalva or often called sinus of aorta into the coronary arteries Heart rate may change upon exertion in the cases of babies the heart rate responds to excitation or stimulation Compared to adults babies heart rates are significantly higher 9 As they age it will drop down slowly The pattern of the heart beats can be measured by EKG often referred as ECG electrocardiogram It is done by placing electro leads in various spot of the body which measures current from one end to the ground lead Heart rate changes from t
25. boasts 3 axis measurements It contains 14 bit and 8 bit resolution onboard ADC s and user selectable ranges of 2g 4g 8g It too like the ADXL362 can be put into a sleep mode during motionless states of the infant being monitored The MMA8451Q has output data rates of 800Hz Output data is transmitted over IC to the microcontroller It also has a 32 sample FIFO which acts similar to the other two devices in question The supply voltage is from 1 95v to 3 6v which is in the project operational input voltage At data rates of 800Hz the device is drawing 165uA and a mere 1 8uA during standby Figure 14 below shows the dimensions of the device 39 16X 0 30 0 18 16X 0 567 5 0 367 PIN 1 INDEX 16X 0 667 0 46 VIEW M M Figure 14 Bottom dimensions of pads for the MMA8541Q Reprinted without alteration with permission by Freescale Semiconductors It s a 3x3mm QFN The leads are 3mm in width and 567mm in length This QFN is a little different than the MPU 60x0 series in that the leads are not visible from the side edges of the device It s more similar to the ADXL362 LGA package This again surfaces the problem of being able to see if the device is properly soldered down A hot air pencil or solder reflow machine would have to be used in the mounting of this component One of the best features of this device is cost Digikey shows this device at as little as 1 82 and the lead time is 0 weeks as this device
26. bypass mode The output of the DC DC converter is connected to VIN via an internal bypass switch Pulling this pin to high enables the DC DC converter operation This pin must be terminated and is controlled by the system UT This is the switch pin is connected to the internal MOSFET switches Feedback Pin for the internal feedback divider network and regulation loop The internal bypass switch is connected between this pin and VIN OUT This is the open drain status output with active low level An internal comparator drives this output The pin is high impedance with ON BYP low With ON BYP set to high the device and the internal VOUT comparator becomes active The active low STAT pin indicates if the DC DC regulator is settled and the output voltage above the Vystar threshold If not used this pin can be left open Ly FL VES gt ES rf HA RSE he A OA ALL La e o LA NNN m2 E a lope 1mA 061 TPS62730 ON BYP High Vin 3 6 V pr WALI TILT TT Y VA T eare MAR LU i o 50 1 10 00 21 23 25 27 29 31 33 35 37 39 lg Output Current mA Vin Input Voltage V Figure 29 TPS62730 Efficiency Charts Reprinted without alteration with permission from Texas Instruments Efficiency lor 100 A _ Coyy 2 2 uF Figure 30 below illustrates the internal components of the TPS62730 with a functional block diagram The ON BYP input on the left side determines the running mode When the pin
27. care of skin temperature The MPU also has a unique proprietary Digital Motion Processor The DMP offloads the motion processing computations from the system microcontroller and performs them on its own chip This minimizes the amount of processing power consumed by the system processor There are different current consumption applications because each feature of the MPU can be configurable to be either off or on Since the baby peas peripheral device wants the desired accuracy it will run all three characteristics accelerometer gyroscope and DMP during operation Running all three options will result in 3 9mA operating current This should be well in the desired operating current to allow for the baby peas peripheral sensor to run through the night The idle mode operating current is SuA with a 100ms ramp rate for the device to return to full operation Figure 12 below is a diagram of a standard QFN 24 pin 4x4mm PCB layout example 37 Figure 12 PCB Layout Diagram for a QFN 24 pin 4x4mm package The MPU 60x0 series is a QFN package Quad Flat Pack no leads From the Figure 12 above we see there is a substantial ground plane and 24 pins to be soldered Solder ability of a QFN can be difficult especially when the total dimensions of the part are 4x4mm shown by dimension A x B in Figure 12 and each lead is 25mm shown by dimension a While QFN s may be considerably harder to solder down it is possible by using a reflow machine
28. caregiver Separation from the caregiver may cause anxiety to the infants which have negative impact in the quality of sleep Social and environmental exposure will have an effect to their sleep as well Toddlers one to three years of age have longer sleep spells and the nap time is reduced to once a day which lasts one to three hours Separation anxiety social and motor development can affect the toddler Nighttime fears and nightmares have negative impact on their sleep They often show symptoms such as drowsiness and lack of energy during the day Providing a stable environment is the key to ensure quality sleep 1 While easy on paper the act of normalizing a baby s sleep pattern is difficult and can prove trying for any new parents A baby monitor such as Baby peas can help to quantify the amount of sleep and the pattern of sleep the baby is experiencing The caretaker can look at the trend in sleep and determine the next steps 3 2 1 2 SIDS Sudden infant death syndrome SIDS is the sudden and unexplained death of an infant who is younger than a year old SIDS can affect even seemingly healthy babies Most instances of SIDS deaths are associated with sleep where there is an infant is unable to properly react to a life threatening situation A SIDS diagnosis usually occurs when all other causes of death have been ruled out Most SIDS deaths occur between the ages of two and four months Racial statistics show that African American and
29. different Phone Move display radial pomts device 100 feet away from the sensor Table 36 Weight Battery life and Wireless Range Final Test matrix 119 7 Administrative Content The administrative content of the Baby Peas project group consists of project schedules milestones charts and group roles and responsibilities It is of the highest importance the administrative duties to not be let go by the way side but are adhered to strictly 7 1 Milestones and Schedule Discussion The baby peas project was under and extremely tight schedule due to the nature of trying to come up to speed on android application development Bluetooth low energy development PCB circuit design and component interactions It was the intent of the group to have weekly and sometimes bi weekly meetings to discuss actions of the week and to monitor the progress of the schedule milestones Table 37 and 38 below are the Hardware and Software milestones chart respectively and weekly schedules for Senior Design 1 Fall 2013 5 Aug 19 Ang 2 Sep 16 Sep 30 Sep 14 Oct 28 Oct 11 Nov 25 Nov 2 Dec Hardware Tasks W1 2 W34 W5 6 NN 8 o 10 12 NN 14 B 16 18 W19 Research projects Determine appropriate sensors for development Determine appropriate microcontroller for development Look for integration projects sheets for each sensor and start on document Research power 15 of document done Regroup and see f software and hardware are compatible and ha
30. entire unit In addition figure 40 shows the thermal pad of TPS62740 Special care should be made when soldering the thermal pad as it acts as the heat sink for the regulator and any defectiveness in contact could mean catastrophic consequences for the entire unit A figures not created in Eaglesoft are courtesy of Texas Instrument s datasheet for the TPS62740 68 U1 CC2541_RHA_40 est pps 3 JPS62740 Pasha 26 JE past 25 1 ge E pRO V1 paps 30 yO ps5 40 12yo e 20 44 OUF 6VDC 11 40 a vary 19 Y END 8h ae 18 1940 BATTERY pep 17 A GND ME 16 gy payo 15 ta pars 14 dye Pasha 13 o pasa 12 m 3 Feo O P2_3 0SC32K_Q2 m di P2_4 0SC32K_Q1 END A XOSC_Q1 XOSC_Q2 Ah OO0000010 O NC o o oo o vov e k R p Figure 35 Configuration for integration of TPS62730 with the CC2541 Created using Cadsoft Eagle 3 10 2 90 12 7 Nm LO O Pin 1 Index Area 1 6 Top and Bottom 0 10 OJeTala Figure 36 Shows the Package Size and Pin Size of TPS62730 69 0 20 Ref A PIN 1 INDICATOR RO 10 O A E DOSE d Thermal Pad e Y 0 50 ji A A PULTE UE LE ut I 12 0 65 lt 2 00 0 10 Figure 38 Shows the Thermal Pad for TPS62730 4 Project Hardware and Software Design Details 4 1 Hardware The Hardware high level System block diagram shown in Figure 39 gives a nice overview of each subsystem and on h
31. groups and each of the heme group can bind to one oxygen molecule Some oxygen can be dissolved in the plasma While the dissolved oxygen is the minority 3 compared to the oxygen content of the body they play a crucial part in deliveries of oxygen to the tissues Body temperature pH abnormal hemoglobin concentration of carbon dioxide and concentration of carbon monoxide can have physiological effect on the deliveries of oxygen as shown in Figure 1 With portable pulse oximeter sensor such as Baby Peas monitor the oxygen saturation can be closely monitored at all times Left shift Decreased temp Decreased 2 3 DPG Decreased H CO A Right shift reduced affinity Increased temp Increased 2 3 DPG Increased H 2 g 5 5 v Be E E E y 5 6 10 20 30 40 50 60 70 8 90 Po mmHg i Anaesthesia Figure 1 Oxy Hemoglobin Dissociation Curve This image has been reprinted from AnaesthesiaUK with permission www AnaesthesiaUK com In general blood oxygen level measured by the pulse oximeter is accurate in most cases it is important to consider other factors in certain scenarios 3 2 1 3 3 Heart Rate The heart 1s the vital motor to the body just like the engine is to a car Blood is the organ being transported by heart to the rest of the body Nutrients wastes oxygen are carried in the blood along with antibodies and foreign material fighting agents There are four chambers in the heart right
32. iPhone application has been developed and released the developers are currently working on android counterpart Upon the product debut both platforms will be available to the consumer The applications can be used with tablets as well 7 The notable features on Owlet Baby Monitors Washable when the electronics are pulled out from the Smart Sock Capable of monitoring more than one child at the same time Cloud storage of data Crowd funded 3 1 2 KnightTime KnightTime is developed by a group of senior design students from University of Central Florida in 2013 The group members were Anthony Bharrt who was a computer engineering major student as well as Facundo Gauna The rest of the team members are Ryan Murphy and Bartholomew Straka both electrical engineering students The motivation of the project was to improve the quality of the sleep from data collected by biomedical sensors Individuals could utilize the information gathered from the sleep management system to make decision or adjust personal habits in order to improve the quality of sleep The key points measured by the KnightTime system are temperature body movement and heart rate The wearable product was designed to be comfortable and non irritable Based on the collected data software algorithms can determine the sleep stage of the individuals and wake them up once the sleep duration is met Battery was crucial on this project because 1t had to provide the necessary power to t
33. implemented if deemed appropriate Bugs in the operating system and efficient programming can be more quickly dealt with in this way Android applications can be downloaded through the Google Play store or the Amazon Appstore To begin developing an application as a third party the Android Software Development Kit must be obtained This can be achieved by purchasing the ADT Bundle from Android The bundle includes the Eclipse Integrated Development Environment plugin ADT plugin Android Platform tools the latest Android platform and the latest Android system image for the emulator Android apps are usually programmed in Java 56 3 2 8 Microcontroller FPGA The microcontroller is an essential part of the overall project The function and data flow of the sensors is determined by the microcontroller When selecting the appropriate part for the wireless sensor the performance and power consumption are the primary specifications to consider This is because the microcontroller will be mounted on a peripheral unit and act as part of a wireless transmitter The MCU should use a minimal amount of power to maximize battery life while being able to achieve the necessary performance standard needed for its actions The data processing required will have to do mostly with interpreting analog data coming off of multiple sensors measuring vital signs and position The microcontroller needs to have at least 4 analog to digital converters one for each sensor
34. model versus the voltage of the battery The TPS62730 minimizes the current drawn from the battery during both transmission and reception modes The graph shows a clear reduction of battery current used as the voltage increases This decrease in current allows the prolonged use of the powered device in transmission mode A long battery life is essential to the use of the project The longer the battery can be powered without recharge the more useful and convenient the device will actually be This ensures the child will be monitored through a longer uninterrupted period of time where parents do not have to constantly worry about how much battery life is left This device supports Lithium powered battery chemistries such as LiSOCl LiSO LiMnO2 and other two cell alkaline batteries 0dBm CW TX Power 25 DA NX Battery Current Reduction IND Battery Current m Battery Current Reduction of CC2540 17 2 4GHz Bluetooth Low Energy System On Chip Solution 322 24 26 28 3 32 34 36 38 Battery Voltage Vaar Figure 26 Current vs Voltage with TPS62730 Reprinted without alteration with permission from Texas Instruments 59 The Figure 27 below show the relative current consumption during data transmission The bottom axis is labeled as supply voltage increasing from left to right The left vertical axis is labeled as current in mA increasing upward The blue bar shows the current consumption at its corresponding voltage without usin
35. sids prevention page 1 gt Centers for Disease Control and Prevention Centers for Disease Control and Prevention 09 Aug 2013 Web 18 Nov 2013 lt http www cdc gov sids gt Moon Rachel Y SIDS and Other Sleep Related Infant Deaths Expansion of Recommendations for a Safe Infant Sleeping Environment Official Journal of the American Academy of Pediatrics 128 5 2011 1341 367 Web Accelerometer vs Gyroscope What s the Difference LiveScience com 20 Nov 2013 lt http www livescience com 40103 accelerometer vs gyroscope html gt A Beginner s Guide to Accelerometers A Beginner s Guide to Accelerometers N p n d Web 21 Nov 2013 lt http www dimensionengineering com info accelerometers gt Accelerometer Gyro and IMU Buying Guide SparkFun Electronics Accelerometer Gyro and IMU Buying Guide SparkFun Electronics N p n d Web 21 Nov 2013 lt https www sparkfun com pages accel_gyro_guide gt Abidi Asad Gregory Pottie and William Kaiser Power Conscious Design of 130 42 43 44 45 46 47 48 49 50 51 52 53 54 55 Wireless Circuits and Systems Proceedings of the IEEE 88 10 2000 1528 545 S Web 01 Dec 2013 The Fatal Current New Jersey State Council of Electrical Contractors Associations Inc 2 13 1987 n pag Electrical Safety Web 29 Nov 2013 United States of America Occupational Safety and Health Admi
36. simple act of walking across a carpet can generate up to 35 000 Volts 38 Table 7 shows some additional voltages that can happen Static generation Electrostatic voltage V at 10 relative humidity Walking across vinyl floor 12 000 Worker at bench without wrist strap 6 000 Styrofoam packing 120 000 Picking up common plastic bag 60 000 Table 7 ESD generation from various activities 48 ESD prevention is a mixture of technique workstations and atmosphere At the crux of electrostatic protection is keeping the potential between the technician and the board the same Because the work on this project is being done during the winter it is crucial to make sure that the surrounding atmosphere of the work area is high in humidity the lower the humidity the easier for static to build A humidifier could help with this or even leaving out a body of water can help In addition all of the workstations where component touching can happen whether it is soldering or just simple handling need to be grounded to a common ground A simple dissipative mat wrist strap and finger cots can help prevent potential different buildup on the person s body relative to the board Each of those components help drain the body voltage and prevent body voltage buildup In addition they are often nonintrusive and cheap Finally any transportation of the boards or sensors outside of the final packaging must be carried with shield bags Note ESD protection is
37. the piezoelectric effect which means they contain microscopic crystals which are stressed by the forces of accelerations These crystals begin to slightly vibrate which will cause a voltage to be generated Voltage proportions can be used to determine levels of accelerations Another way is for the device to measure changes in capacitance This is done by placing two structures close to each other to form a capacitor and if any movement occurs the structures could move causing a capacitive change which can be monitored as well to determine acceleration For accuracy purposes accelerometers can determine 2 dimensional positions or 3 dimensional positions Since accuracy 1s critical a 3 dimensional device which measures the acceleration at 3 axes is better suited to the 66 99 project Another aspect to pay attention to with accelerometers is their g level of range 15 66 99 The g level corresponds to reference points The g values also can be referred to as the measurement of the acceleration component of gravity on Earth which is 9 8m s So Earth s gravity is 1g 39 While a higher g may mean the range is greater it does not necessarily mean the precision is better If the object in which we are trying to measure isn t going to accelerate at more than 2g s then there is no reason to have a device which can measure up to 24g s Determining what the max acceleration a human body part can move in terms of g
38. to the 8051 core architecture and the memory associated with the 2541 This includes RAM ROM flash memory and the memory arbitrator Data buses are also grouped together in this category Power test and clock distribution modules are lumped together This refers to the VDD pins debug pins crystal oscillator pins and timers The radio related modules are the RF pins that receive and transmit wireless data to other peripherals The Block Diagram of the CC2541 can be referenced in Figure 49 for the RF portion of the project and Figure 50 for microcontroller aspects of the project 4 1 4 4 CPU and Memory The CPU is the source of all essential mathematical data manipulation that occurs throughout the microcontroller The data is then sent out to its appropriate destination as designated by the coding The Direct Memory Access DMA is the component used to actually move the data around thus enabling the CPU to concentrate on other processes The CPU and DMA are connected by the Memory Arbiter Data that must be reserved for later is stored in memory where it can be later accessed if needed for other miscellaneous tasks Ultimately the success of the project depends on efficient use of the CPU and memory modules Referenced to Figure 50 8051 CPU core o Single cycle 8051 compatible core o Three different memory access busses SFR DATA and CODE XDATA o Debug interface o 18 input extended interrupt unit e Memory arbiter o Connects CPU and DM
39. up and running Input Voltage volts 3 3v RX current 10 mA TX current 40mA Power Output 6dB Receiver Sensitivity 87dBm Frequency 2 4 GHz Data Rates 250 kbps 500 kbps 1Mbps 2Mbps BER lt 1 Bluetooth Protocol BLE v4 0 and Bluetooth classic Solder Package 34 pin Cost 12 95 Amazon Lead Time Ready to Ship p Table 14 HC 06 device specifications 3 3 6 3 nRF51822 BLE Module The nRF51822 Bluetooth Low Energy Module is made by Nordic Semiconductor It too is a true system on chip as it incorporates a Bluetooth radio along with a microcontroller The Bluetooth Radio specifications are listed in Table 15 1 8 3 6v Table 15 nRF51822 Bluetooth low energy module specifications 49 The nRF51822 uses a 2 4 GHz RF transceiver along with an ARM Cortex MO 32 bit processor The 2 4GHz Radio can be configurable to not only Bluetooth but ANT and other worldwide ISM band standards Qualified Bluetooth low energy stacks are available in the s100 series of SoftDevices and the protocol stacks can be downloaded from their site for free Unlike the other two devices is boast a 30dBm TX power Whisper mode It has 31 general purpose IO s which 8 can be configured to be ADC s The ADC s have resolution of 10 bits It has either 128 or 256kb of flash program memory and 16kB of RAM The nRF51822 comes in both a 48 pin QFN package and a BGA package The Baby Peas project would be looking for something a little easier to solder so we wo
40. was used in order to look for drastic changes in position rather than slight changes which was better suited for the Baby Peas Project 3 3 5 Skin Temperature Sensor The application requires small form factor in order to be applied to the ankle on an infant Using semiconductor based sensor we can achieve ultra low power consumption with a form factor less than 3 millimeter squire 3 3 5 1 TMP006 The first candidate under consideration is TMP006 from Taxes Instruments TMP006 is meant for non contact remote temperature monitoring TMP006 is an infrared thermopile sensor with a size of 1 6mm by 1 6mm The temperature of the object is measured by the thermopile on the sensor The thermopile converts thermo energy infrared energy emitted by the object in this case into electrical energy An output voltage is created based on the difference to the local temperature TMP006 operates between minus 40 degree Celsius to 125 degree Celsius The way TMP006 communicates is thru SMBus System Management Bus or SMB SMBus is a derivative of PC which is compatible with our desired microprocessor CC2541 from Texes Instruments Two variants of TMP006 are available TMP006 and TMPOO6B The main difference is SMBus interface voltage TMP006 is at 3 3 V while TMP006B is at 1 8 V The two main constrain of using TMP006 are surface emissivity and target size to sensor placement Surface emissivity It is a measurement of a surface that emits energy thermo energy
41. 0 mA With a metalized ceramic package it can be soldered onto PCB along with other components fairly easy DPI E839 is ideal to be used with AFE4490 for Baby Peas monitor The only downside is the unit price It carries a hefty unit price of 5 95 available on Octopart QEB363 is an infrared emitting diode manufactured by Fairchild It can be paired with QSB34CGR photodiode sensor It emits wavelength of 940 nm With a small T 3 4 2 mm package and extended lead it can be mounted in three different configurations The overall size without counting the lead is 2 2 mm x 2 5 mm x 3 0 mm it has a power dissipation of 100 mW and continuous forward current of 50 mA Additional 640 nm LED must be paired with QEB363 for using as pulse oximeter Marktech optoelectronics manufactures wide selections of 640 nm light emitters The particular model best suits Baby Peas monitor is MTES5066C UR It has a similar form factor of 3 1 mm x 3 1 mm x 4 3 mm Although slighter bigger the difference can be neglected because their small size in nature The power dissipation is 110 mW with forward current of 50 mA according to datasheet Combining QEB636 with MTES066C UR should have similar performance of a single DPI E839 In Conclusion the Baby Peas monitor used a discrete reference design offered by www pulsesensor com This design allowed only the heart rate portion of the project to be implemented and the sensitivity only allowed us to gather heart rate information f
42. 1 RHA 40 OF1 HELE Ur 5 lt N ELLE Figure 40 Schematic Diagram Shows Texas Instruments AFE4490 connected to Texas Instruments CC2541 System on Chip Schematic Created in Cadsoft Eagle by Yowwu Lin The SPI interface pin connection can be found on CC253X 4X User guide The circuit was created using Cadsoft Eagle All the capacitor and resistor values were specified in AFE4490 datasheet In the end a discrete design was implemented an can be shown in Figure 41 below The design was implemented using Cadsoft Eagle and derived from the reference design provided by www pulsesensor com A AWW WWy 4 I Figure 41 Pulse Sensor Circuitry Schematic Created in Cadsoft Eagle by Christopher Ramirez 72 4 1 2 Body Position Sensor Design For the body position sensor the IMU 6000 was chosen from Invensense Figure 42 below block diagram of the connections between the MPU 6000 and the Atmega328p Microcontroller Atmega 328p MPU 6000 SDA Pin 27 Pin 24 SDA SCL Pin 28 Pin 23 SCL QA QZ gt 0 o A a A V_REG_ GND Figure 42 Block Diagram for Body Position Sensor From Figure 42 we see the data transfer and communications for the device will be using IC The SDA line is where the data will move through serially The SCL line is the clock and SDA line is used for data transfer The Atmega328p IC lines for SCL and SDA are hard line wired to Pins 27 and 2
43. 3 8 1 Battery As discussed above in section 3 2 9 1 2 the best packaging for the portable power source is the button package After determining the needs of the sensor modules and central processing unit the best battery for the job would be a LIR2477 It is a 3 7 volt 160mAh battery with 500 cycle life times Ideally during a day of normal usage the user charges the battery once every two days time At this rate the battery should have an average lifetime of over 3 years The cut off voltage of the battery 1s 3 volts and the max discharge current is 300 mA 3 3 8 2 AC power supply As discussed in section 3 2 9 2 it would be too dangerous to make an AC to DC power supply due to lack of expertise and proper personal protective equipment A possible choice for the Baby Peas unit would be a consumer grade wall mount charger PowerStream sells such a unit called the wall mount lithium ion coin cell and lithium polymer battery charger at a very reasonable price and for the battery that was chosen for the portable unit According to the PowerStream website it is a dual charging unit with indicators showing charge status and polarity Having a well tested unit will be invaluable to the well being of group members and any test conditions 3 3 8 3 DC power supply 3 3 8 3 1 USB In addition to the AC power supply a DC power supply can also be implemented In fact in some cases it might be even more desirable due to the widespread usage of USB p
44. 7 pdf document was also wondering if you be able to email me the originals of those figures We have to print out the document in 300dpi and some of the figures don t look that great when take a screen shot and paste them into the paper Thanks so much for you help Take care Christopher Ramirez Electrical Engineer University of Central Florida cramirez36 cfil rr com How to best communicate with us regarding this Service Request SRA 1 1214068461 e You may reply to this message by email Make sure the SR number is included in the subject line e lf you need to send large attachments upload them on the details view page e Go to http www freescale com techsupport for complete details on all your SR options or to create a new SR Subscribe to Freescale s Design News our weekly email newsletter Be the first to hear about 133 embedded news technologies product launches and events You ll also receive errata notices and other updates based on your product and application preferences You may also access Freescale s portfolio of embedded processing solutions from the convenience of your mobile device Visit http www freescale com mobile to get started 3 Texas Instruments From support ti com mailto support ti com Sent Thursday November 21 2013 6 46 PM To cramirez36 cfl rr com Subject RE GEN Email Technical Support www ti com n a 1 1215158584 christopher Thank you for contacting TI customer support and thank
45. 8 respectively V_REG will be the input voltage line from the regulator circuit and GND is connected to system ground Figure 43 is the schematic diagram layout for the MPU 6000 73 Ui INVENSENSE_6000 Ji Slave Address 068 Figure 43 Schematic Diagram for Position Sensor Utilizing Cadsoft Eagle Circuit created by Christopher Ramirez 4 1 3 Skin Temperature Sensor Design For the Skin Temperature Section the TMP006 was chosen because of its ability to read temperature without having to make contact with the infant Figure 44 below is the block diagram of the connections of the TMP006 with the Atmega328p Atmega328p TMP006 SDA Pin 27 Pin C3 SDA SCL Pin 28 Pin B3 SCL Pin 6 Pin C2 DRDY o B A Z gt 0 o A e A A Figure 44 Block Diagram for Skin Temperature Sensor 74 From Figure 44 the data transfer lines are utilizing I C as well communications between the TMP006 and Atmega328p The only difference is the designation name for chip select on the TMP006 which is labeled as DRDY instead of CS The over line means the line is active low Pin 6 on the Atmega328p is another digital I O line It is port P1 3 and is used for toggling the chip select line Figure 45 below is the schematic diagram for the TMP006 created in CADsoft EAGLE Slave Address Ox40 Figure 45 Schematic Diagram for Temp Sensor Utilizing Cadsoft Eagle Circuit created by Christopher Ramirez If the TMP006 proves to be difficult to work with will
46. A controller with physical memories and all peripherals through SFR bus o Four memory access points SRAM Flash memory XREG SER registers o Responsible for performing arbitration and sequencing between simultaneous memory accesses to the same physical memory e SFR bus o Connects hardware peripherals to memory arbiter o Provides access to radio registers 8 KB SRAM o Maps to DATA memory space and parts of the XDATA memory spaces o Ultralow power non volatile SRAM power mode 2 and mode 3 128 256 KB flash block o In circuit programmable non volatile program memory o Maps into CODE and XDATA memory spaces 79 4 1 4 5 Peripherals The peripheral modules support the core CPU and memory modules in running the microprocessor by controlling the flow of data to or from the central components The DMA Interrupt and Input Output controllers all administrate the accurate transfer of data within memory and with external sources The timers specifically control the timing of the system providing an ordered sequential structure to the various processes that take place The rest of the peripheral modules including the UART IC SPI and AES components enable the communication of data between devices The project will be exchanging data between components so these peripheral modules will be used extensively Referenced to Figure 49 e DMA controller o Five channel Trigger Priority Transfer mode Addressing mode source and destination poin
47. BABY PEAS Pulse Early Alarm Sensor A non evasive vital monitoring system providing caretakers power to make data driven decisions for an infant s wellbeing Department of Electrical Engineering and Computer Science University of Central Florida Dr Samuel Richie Senior Design 2 GROUP 4 Christopher Ramirez 407 310 0830 cramirez36 O cfl rr com Xin Tong 407 4378604 x tong knights ucf edu Yowwu Lin 407 435 7804 wasiasd knights ucf edu Benjamin Goolsby 904 347 7935 goolsby knights ucf edu TABLE OF CONTENTS Ue MES CU SU VARY AMM l 2 PO DETO a E E ddienos 2 om Project Motivation and Goals oooooonnnnnnnncnnnononccnnnnnnnnnnnnnnnnnnnnnnonononananncnnnnnnnos 2 2 2 OCIS A E E E E A EN E AAN A E E A ET 2 2 3 Project Requirements and Specifications ccccccccccccesseeececeeeeeeeeeeeeeeeeeeeeeaaas 2 3 Rescarch Related to Projeti anresisaet bo 3 3 1 Existing or Similar Project and Products ccccccccccccccesseeeceeeeeeeeeeeesseeeeeeeeeaaas 3 N A E a a AE AE AE E 3 lao MI IO E E er 4 3 1 3 Current Majority Market Share Monitors ccccccccconooncnnnnnnnnnnnnonocnnnnnnnnnnnnnnos 4 32 Relcvint ToColor Con ee ee ee E E e EE a ES J ng E E T E E T a ESA a AAA ei O 5 A A eee AePeePex zxe P eee 6 IS A A II sess aac ence EER 7 iD slic ds AA E a 7 Pe L ae ODA OXY COM OVS dices 8 PU ME 2 VC ATS AUC ROPAS A A E A A E 9 Dia ae SEAS AL paa 10 3 2 2 Pulse Oximetry Sensors cccccccccooooonccnnnoncnnnn
48. DFM 4PCB Import Changes Order PCB HW Milestone 1 comp Solder Batt Reg Charge Reg Test into D Load Populate PCB Full Load Microcontroller Code Test Temperature Sensor Test Position Sensor Test Pulse Oximetry Sensor Test RF performance Test Battery life specs Test Recharge CKT Mod Micror Code Finalize Micro Code Reload Micro Code Repeat Test Matrix HW Milestone 2 comp Design Review WW mods Small PCB design New Layout Comp DFM to 4PCB Order Final PCB Populate PCB Full Repeat test matrix y HW Milestone 3comp Jo Table 39 Hardware Tasks Milestones Chart Senior Design 2 Hardware Tasks are driven with respect to completing the PCB design and performing a PCB design review before the start of Senior Design 2 4PCB manufacturing house offers free Design for Manufacturing checks on the PCB to be sure all specification of the PCB design layout allow the PCB to be built within standard practice tolerances Once the DFM is approved by 4PCB the PCB can be placed on order Upon ordering of the PCB Milestone 1 will be complete 4PCB has between a 3 to 4 day turnaround Once the PCB is received the first circuits to be implemented will be the battery recharge circuit 122 and regulator circuit Design measures were taken to allow the output of the regulator to be connected to an external dummy load by removing a series resistor and connected in a high ohm load along with a low ohm load and driving a FET with
49. I p f mransurr FREQUENCY cl lia Figure 48 CC2541 Block Diagram used with permission from Texas Instruments 82 4 1 4 6 Application information CC2541 The schematic configuration of the CC2541 is shown again in Figure 50 The remaining sections walkthrough the different uses of the pins which have not be covered yet Y gt gt lt Y Y Y CC2541 S E MURATA BALUN El Y 7 E H BB esp X1 OSC 32 768 KHz HIF X1 OSC 32MHz Cc X TF 2 Y Figure 49 Schematic design for the CC2541 Communications Microcontroller Created in Cadsoft Eagle by Christopher Ramirez 4 1 4 6 1 Power configuration A 2 to 3 6 Volt power supply is connected to pin 10 21 24 27 28 29 31 and 39 Each of these pins are a DVDD or AVDD pins which are the Digital voltage inputs and Analog voltage inputs These can be tied together because a separate digital voltage line 1s not being used in the Baby Peas project XOSC_Q1 Pin 22 XOSC_Q2 Pin 23 These two pins are attached to an external 32 MHz oscillator This oscillator is used to clock the central operations of the CC2541 hardware RBIAS Pin 30 The resistor R301 is attached from pin 30 to ground This resistor is used for internal biasing The biasing resistor will add voltage offset where needed and stabilize transistor current to avoid saturation or cut off
50. INN INS T TT stant 1 2 r 2 a oOo A STOP Condition S RW ACK ACK Condition P Figure 54 I2C Module Data Transfer Reprinted without alteration with permission by Texas Instruments 4 1 4 6 4 8051 CPU The 8051 contains internal ROM and RAM with a Harvard architecture This means the CPU can use the same address in different memories for code and data The memory where the address is accessed by the circuitry determines the nature by which the address is used This is in contrast to Von Neumann architectures which use a single memory address for either code or data but not for both The decision to use the address as data or code is based on the way the address is accessed Programming the CC2541 to correctly handle the allocation of memory is an essential component of this project The 128 byte internal RAM is divided into three areas e QOh 1Fh 32 working registers organized as four banks of eight registers each e 20h 2Fh Bit addressable memory a total of 128 addressable bits Bit addresses can be specified from 00h to 7Fh Byte addresses can be addressed from 20h to 2Fh For example in this organization scheme bit address 4Fh can also be referred to as byte address 29h This memory layout allows the memory to be conserved For instance a single bit needing to be changed will only use that one bit An entire byte does not have to be used for every action e 30h 7Fh General purpose RAM addressable as bytes Internal ROM
51. If an object has a potential to release an energy value of 200 Jules but only emit 150 Jules by measurement It has an emissivity value of 0 75 from 150 200 A perfect material with a surface emissivity 1s called a blackbody with a value of 1 For example concrete has surface emissivity of 0 85 In our application the human skin has emissivity of 0 98 to 0 99 TMPO006 is capable of calculating temperature from subjects with surface emissivity greater than 0 7 and preferable greater than 0 9 Target size to sensor placement TMP006 is capable to receive signals 180s directly in front of the surface The angle of incidence is related to percentage of infrared signal absorbed as shown in figure 15 at O degree angle of incidence 100 of the signal is absorbed The sensor should be placed parallel to the surface of the object to achieve the maximum IR signal absorption 41 Percent of IR Signal Absorbed 96 100 50 0 50 100 Angle of Incidence degrees Figure 15 Angle of incidence with respect to IR signal Absorption Reprinted without alteration with permission by Texas Instruments A paper cone method was developed by Texas Instruments as a design guideline for TMP006 The field of view must be determined in order to proceed further measurement In our application the subject is the skin of a baby s heel A radius of a one centimeter would be sufficient The area is about 3 14 centimeter square The paper cone method r
52. Instruments TPS62740 is the recommended voltage regulator for this project due to its compact size and power parameters In addition the family of TPS627XX has proven suitability in a design with the CC2541 this is the regulator that the TI sensor tag developmental kit uses That kit is using a TPS62730 a lower voltage regulator than the TPS62740 TPS62740 has a new DCS Control feature that incorporates a tiny inductor and output capacitor to improve efficiency during times of low power usage DCS Control or Direct Control with Seamless Transition into Power Save Mode is a topology trademarked by Texas Instruments and this topology was developed to aid power density and efficiency This Direct Control with Seamless Transition into Power Save Mode incorporates AC control loop Voltage feedback loop and internally compensated regulation network The AC control loop takes information about output voltage changes and feeds it directly to a fast comparator stage for immediate response to dynamic load changes This feature in addition to the voltage feedback look feature which helps to sharpen DC load regulation allows for a clean and stable output In addition the internal compensated regulation network is a great buffer package that is able to dynamically 63 stabilize with external components The DCS control topology switches between pulse width modulation and power save mode for efficiency for both medium to heavy loads Pulse Width Modul
53. MII 8x Vias 30mil Diameter 15mil Hole JP Decoupling Oki Figure 17 PCB suggested layout of TMP006 on a two layer PCB Reprinted without alteration with permission from Texas Instruments 43 Copper Fill 15milx15mil VY Pad Spacing 0 5mm Figure 18 Enhanced view on TMP006 each component will be described in further details Reprinted without alteration with permission from Texas Instruments all ADRI Address pin selection SCL Serial clock line for SMBus open a drain requires pull up resistor to V C2 DRDY Data ready active low open drain requires pull up resistor to V C3 SDA Serial data line for SMBus open drain requires pull up resistor to V all Table 11 Pin descriptions of TMP006 Al and A2 are the ground which will be connected to the common ground with pulse oximeter ground along with CC2541 microprocessor SDA SCL are SMBus compatible interface under PC protocol and 10kQ typical value is as suggested pull up resister per Texas Instruments DRDY pin is output voltage with 0 15 V typical and 0 4 V maximum A3 is the main supply voltage pin for TMP006 with maximum of 7 V ADR is input pin with voltage of 0 5 V to Vs 0 5 V Maximum input current is 1OmA combined To 44 calculate the temperature we have given values from Texas Instruments for each component Please refer to Table 12 Please note that the final value will be in Kelvins Description Value VOBJ volt
54. Native American infants are two and three times as likely respectively than Caucasian infants to be struck by SIDS 21 Several factors are thought to exacerbate the probability of SIDS these factors are both environmental and genetic Stomach sleeping is thought to increase the risk of SIDS This danger comes from the infant being in a position to restrict airflow as the baby lacks strong stomach and diaphragm muscles to fight against the force of his her own weight on the lungs In addition to no completing a full breath and not getting enough oxygen another possibility is that the infant 1s rebreathing his or her own exhalation This could be caused by the infant s weight or by the infant s mouth being surrounded by stuffed toys or blankets Both factors of the elevated carbon dioxide levels and lack of oxygen could contribute to SIDS Another possible cause of SIDS is an abnormality in the arcuate nucleus a part of the brain that helps control breathing and awakening during sleep Usually a lack of oxygen will cause the infant to wake up and cry changing the breathing pattern and allowing oxygen levels to return to normal A dysfunctional arcuate nucleus would not cause this involuntary reaction and increase the chance of SIDS 22 Sudden unexpected infant deaths may also be explained by poisoning metabolic disorders hyper or hypothermia neglect and homicide Other ways to avoid SIDS e Avoid bumper pads in cribs e Studies have shown
55. Stacks are already available Numerous Vendor supported products Compatible will almost all smartphones tablets and laptops Compatible with all OS platforms Very secure 128 bit encryption Minimum interference from household devices using ISM band due to frequency hopping technology e Software implementation is made easy with plenty of vendor support Cons e Max range on LE is 50 meters e Sometimes making a connection between two Bluetooth devices can be difficult 3 2 5 2 WIFI WI FI is one of the most widely used wireless technologies available for home use Around 61 of households within the United States have a WI FI network according to a research study from Strategy Analytics Connected Home Devices services 32 WI FI has a standardized protocol through IEEE 802 11 It uses a star or point to point topology which basically means one WI FI devices acts as the Master and it can have multiple slave WI FI devices it connects too The slaves can only talk with the master and not the other slaves It has very high bit transfer rate 300 Mbps great security WEP WPA WPA2 operates in the ISM Industrial scientific and medical radio band of 2 4 GHz and 5 GHz range of 35 meters indoors high power consumption WI FI has potential to be used in the baby peas project because of its great range and compatibility with mobile phones tablet PC s laptops and Smart TV s and Gaming consoles which all have WI FI integrated circuits whic
56. USB so it is required to have the USB breakout board built before attempting the solar kit 54 3 3 8 4 Board supply Regulator The critical unit for the power supply directly to the board units is the regulator Earlier in section 3 2 9 3 linear and switching regulators were discussed as the two options for the board For linear regulators the low dropout rate regulators were recommended due to efficiency ratio of input and output ratio 3 3 8 4 1 Linear Regulators Linear Tech LT1761 Linear regulator is a well known and well used method to supply the correct voltage throughout the circuit Fundamentally the circuitry uses the voltage divider principle to generate the correct voltage at the output of the regulator and input to the circuit The simplest circuitry would consist of just some resistors and diodes while more complex circuitry might have error corrections measures power protection and voltage references One of the simplest designs is called a zener regulator figure 22 The remainder of the unrequlated The zener diode holds the voltage drops across the resistor voltage constant regardless including the ripple part of the current within limits Within the design limits the load resistor sees a constant Unregulated voltage regardless of current power supply Figure 22 Zener Regulator reprinted with permission from hyperphysics The voltage output is constant due to the constant reverse voltage aspect of the ze
57. act with the Atmega328p over IC whereas the Pulse Sensor uses an analog output to connect with the microcontroller Table 29 displays the test matrix for the Pulse Sensor hardware circuit Test Procede Description Expected Result 1 Proper Solder Connections Measure input resistance on Vinto Verifies the input voltage line to the High impedance ground with a DMM ADS 9800 is not shorted to ground qee on Visually check to make sure the LED the Green LED should be lit LED shoul be ht is on 3 Photo Diode Check Measure in line current to using a Measuring the in line current will Durring LED s on the DMM to verify current pulses are display the Photo Diode is picking Photo Diode Currents present up the light from the LED when should be increasing while they are on when the LED s are off the current should be decreasing OP Amp Output Using an O scope Measure the setting the O scope to time a 1 2hz sign wave pulses Measurements ouput of the operational amplifier devision of around 1 sec should _ should be visible on the O circuit enable the 1hz signal to be seen _ scope while a finger is placed over the sensor Table 29 Test Matrix for AFE4490 Pulse Oximetry Sensor 6 1 2 Wireless Communications Hardware Test Due to the nature of the wireless communications hardware being a System on Chip CC2541 most of the testing on the input circuitry was taken care of during previous testing of the sensors Things which can be tested are th
58. ad resistor can be soldering in via a white wire Another white wire can be connected to the battery terminals allowing for an external power supply to be connected in Table 27 walks through the necessary tests which will be performed 111 o TET _ __ Procedwe Description Expected Result 1 In Out Resistance Checks With DMM Measure Vin and Test validates input and output Vin High impedance Vout pins on TPS62740 are not connected to ground and Vout High Impedance Vin and Vout soldered properly supply to Battery Terminals are properly designed for Input V 3 6v I limit 110mA Voltage Vout Same Vin setup High seton Checking the 3 3v rail to validate Vout 3 3v ki Voltage Measurement Connect external DC power Validates input battery terminals Vin 3 6V measurement pin 12 EN O scope on output switched signal Vripple lt 20mVpp Switched line Test Point Switched Vout response to external High ohm and low ohm Validates output stability of the Output Voltage remains High and Low impedance dummy loads switched by TPS62740 to the varying load stable with no ringing on external fet controlled by resistances experianced during the output after High Low function generator full operation switch Remove External Power Validates the Battery can operate Same as expected results Supply and insert Coin Cell the voltage regulator Battery into Battery holder clip and Retest parts 1 4 Plug in external battery charging Thi
59. ads the temperature immediately upon powered on TMP103 has internal register for data processing The most recent converted data is stored in pointer registers which are configured eight bit read only Read and write command is controlled by two LSB on the register Pointer registers 2 to 7 must be O while in write mode The calculation for TMP103 is relative simple compare to TMOO06 All the measurements are present in binary number which can be converted to Hex number Each degree Celsius is represented as a single bit For example normal body temperature is 37 C it will be stored as 0010 O101 in binary and 25 in Hex Twos compliment is used to represent negative number only Registers started out in Os until first conversion 1s completed Built in watchdog function keeps on track of device temperature compared to stored temperature and make sure device temperature is within set limits Shutdown mode is available for power saving the only portion powered on is the communication interface Shutdown mode is enabled when both MO and M1 bits are set to 0 One shot mode enables a single conversion read out once the conversion is done the device goes back to shutdown mode It is used for power conservation The communication interface is under PC protocol and is discussed in details under section 3 2 6 1 TMP103 provides an easy integration with standard communication interface with CC2541 The drawback of TMP103 is temperature resolution of 1 C
60. ag is set to indicate the end of that section of data Received data occurs in the same manner RI is set to O to indicate the previous data has been read and it is clear to receive the next byte The eight data bits are sent to SBUF the stop bit is put into RB8 of SCON and the start bit is discarded RI is set to 1 to indicate new data 89 is received to be read Timer is used to generate communication frequencies The figure 57 below illustrates the process The first start bit initiates the transfer the 8 data bits are sent then there is a stop bit which triggers the idle time until the next byte is ready to be sent The receiver samples the data at the center of the bit time to make it as accurate as possible The baud rate is determined by the timer overflow flag If timer 1 is not in timer mode 2 the baud frequency is generated using the following equation 75MOD Fhaud 32d timer 1 overflow frequency The term SMOD is the control bit for the special function register PCON and can be either O or 1 The 2 in the equation is raised to either a 1 or 2 respectively Receiver Samples Data in Center of Bit Time wes PPE ete SESSSSSe Start Bit Data Bits 1 Stop Bit min Bit Time gt Figure 56 Standard UART DATA WORD Created by Xin Tong in MS Word 4 1 4 6 4 1 2 Serial Data Mode 2 Multiprocessor Mode This mode is basically the same as the Standard UART mode but nine data bits are sent instead of only eight T
61. age and for lower component cost Due to the two issues discussed above voltage collapse and reverse leakage a chip such as TI s BQ24210 unit would be ideal in implementing in a charging circuit While is nice to have this module to supplement the main AC source it might prove too ambitious for a single semester project to build this additional module If time is sufficient this building this module would very instructional to solar power circuitry and pitfalls 3 3 Strategic Components 3 3 1 Pulse Oximeter Sensor AFE4490 Choosing a sensor that is compact and high integrate capability along with low power consumption is top priority Under close evaluation Texas Instruments AFE4490 is the most suitable for this project It is compatible to multiple microprocessors and wireless Bluetooth modules with maximum 5 25V required Its QFN 40 6mm x 6mm form factor is ideal for implementing with other sensors in small projects AFE4490 uses SPI Serial Peripheral Interface as the communication bus to send digital data to the MCU It has configurable LED circuit drive current which low voltage can be achieved The receiver front end includes photodiode current to voltage converter done by TIA transimpedence amplifier Ambient cancellation scheme estimates amount of ambient light leakage by sampling ambient light with two LED sending data to SPI and transmitted to the MCU The MCU has the information of all the data and able to estimate the amount to
62. age measured by TMP006 stored in register O temperature measured in TMPOO6 stored in register a2 1 2 2 a pe o peoo Table 12 Variable Description and Value There are four main equations for object temperature calculation The thermopile itself must be calibrated over PCB and the energy from ambient environment S So 1 a1 Tprr Tren a2 Tpre Trer 2 The offset voltage from TMP006 itself is calculated by Vos bo b1 Tpre Tren b2 Tpre Trer 2 Seeback coefficient of the thermopile changed based on temperature F Vogy Vos Vos C2 Vop Vos 2 Once the calibration offset voltage and coefficient has been calculated the object surface temperature can be found as in Tos 45 F Voy Top Tp Ce The calibration is discussed in detail in TMP006 user guide which can be found on Texas Instruments website The equations above will be coded on microprocessor for measurement 3 3 5 2 TMPIO03 TMP103 is a four ball wafer chip scale package from Texas Instrument The main communication is a two wire I2C and SMBus interfaces It is capable of measuring temperature from 40 C to 125 C within 1 C resolution With an operating voltage of 1 4V to 3 6V it fits into Baby Peas low power consumption model Its simple design makes easy integration to CC2541 microprocessor TMP103 is the sensor itself thus the ambient temperature must be isolated from the object needs to be measured TMP103 re
63. ain flatness should be 1dB over frequency band with an output power of 10dB Gain flatness should be 1dB over frequency band with an output power of 10dB Gain flatness should be 1dB over frequency band with an output power of 20dB Gain flatness should be 1dB over frequency band with an output power of 20dB O scope will read 32MHz signal with 3 3vpp applitude O scope will read 32 768 kHz signal with 3 3vpp applitude Table 30 Test Matrix for CC2541 Wireless Communications Hardware Once the completion of the CC2541 device has been tested all devices will be inserted back into the circuit and will be ready for system level testing 6 2 Software Prototype Testing The Software testing consists of the CC2541 embedded coding and the user interface display device for Android compatible Bluetooth smart devices Software glitches and non intuitive user interface applications can cause the reliability of the product to be called into question from the user The following table documents the possible route of testing for the software usability In addition to the table the unit should be operated by those who are unfamiliar to the project This ensures that the design of the app is intuitive enough for the lay users 114 6 2 1 CC2541 Software Testing Software loaded onto the CC2541 is imperative for the hardware sensors of the system to work properly The testing of the code will consist of a parallel pat
64. al function registers toggle some setting in the microcontroller For instance the difference between receive data and transmit data is only a few bits being changed This header file also gives an invaluable reference as to the inner workings of the microprocessor The definition of each of the registers and their role will enable the programmer to create a more efficient run time code Hal_types h The HAL types header file defines the different variable types and ensures that the basic value types are defined Include guards are set up as to ensure each type is only declared once Certain function prototypes are also included in the Hardware Abstraction Layer header file This header file is essential to the program because it enables the overall code to be properly defined and all necessary variables are declared Without this header file it would be up to the user to define all variables each time new code is created This would be the source of a number of errors and ultimately cause time to be wasted Dma h The DMA header file declares the variables and functions necessary for the user to code for direct memory access Direct memory access is a feature that allows certain subsystems on the hardware mainframe to access memory independently of the central processing unit The DMA header file includes variable and macro definitions Without the ability of other components to directly access memory the CPU would be occupied 92 totally for t
65. and restrictions see the Content License About Android Legal Support creative commons Attribution 2 5 Generic A This is a human readable summary of and not a substitute for the license Disclaimer You are free to Share copy and redistribute the material in any medium or format Adapt remix transform and build upon the material for any purpose even commercially The licensor cannot revoke these freedoms as long as you follow the license terms 138
66. ary data features For the user interface module testing the data being displayed does not need to be accurate This will be covered in the final system testing Table 32 is a breakdown of the necessary tests which will be accomplished to validate the user interface module software testing Test Procedure Description Expected Result 1 Software SW Compile SW code in Verifies properly Compiled code has no application build Software Development Kit compiled software code erros for Android program 2 Software application Connect USB cable from Verifies proper loading Application load onto load onto smart laptop to smart device and jofthe SW application smart devices is successful device upload application software onto the smart device build 3 Application Logn Open the Application on the This verifies the Application opens and Smart Device and provide a application will open on asks the user for a login Logm the smart device and Login is entered and the start to run application moves to user interface window User Interface Walkthrough all available This verifies all functions All options available open Window options and verify each within the user window quickly and start to option opens into its opens and displays the display the necessary respective function when proper information information requested chosen 5 Sensor Information In the user interface window Main data display Heart Rate Oxygen level choose Moni
67. ata Sheet DS4 430B Microchip Technology Inc 2011 Smith Phill Comparisons between Low Power Wireless Technologies CSR Plc n d Web Oct 2013 lt http www csr com sites default files white papers comparisons_between_low_power_wireless_technologies pdf gt Frenzel Lou What s The Difference Between ZigBee and Z Wave Electronic Design N p 29 Mar 2012 Web Oct 2013 lt http electronicdesign com communications what s difference between zigbee and z wave gt Strategy Analytics A Quarter of Households Worldwide Now Have Wireless Home Networks Strategy Analytics A Quarter of Households Worldwide Now Have Wireless Home Networks N p 4 Apr 2012 Web Oct 2013 lt http www businesswire com news home 20 12040400633 1 en Strategy Analytics Quarter Households Worldwide Wireless Home gt Frenzel Lou What s the Difference between Bluetooth Low Energy and ANT Electronic Design N p 29 Nov 2012 Web Oct 2013 lt http m electronicdesign com mobile what s difference between bluetooth low energy and ant gt Welcome to the Official Bluetooth Special Interest Group Member Website the Definitive Source on Bluetooth SIG Programs Initiatives and Technology Development English Home N p n d Web Oct 2013 lt https www bluetooth org en us gt 10 Steps to Help Prevent SIDS Sudden Infant Death Syndrome WebMD WebMD n d Web 20 Nov 2013 lt http www webmd com parenting baby sleep naps 12
68. ation and light loads Power Save Mode Figure 31 shows the efficiency gains the new TPS62740 offers at low output current 100 95 90 85 O D a iT 75 meni Current CS Control topolog o il Vour 3 3V 60 0 001 0 01 0 1 1 10 100 1000 Output Current mA Figure 31 Extension Range of TPS62740 Efficiency Down to 0 01mA Reprinted with the courtesy of TI documentation on TPS62740 The TPS62740 has improved on the transition between the two modes and decreased voltage ripple and random jitter 55 The older direct current to direct current regulators which switched between the two modes by using physically separated blocks for the two different modes usually set the pulse width modulation mode as default due to the voltage ripple and random jitter However this move cost the regulator in efficiency In the new TPS627XX family the pulse width modulation and power save mode blocks are integrated into a single building block which provides a seamless transition between PWM and Power Save Modes 55 Due to the architecture of the blocks and internal regulation network the quiescent current is 360nA during typical operations Quiescent current 1s an important consideration in the project due to the way the Baby peas unit operates Total battery life comes fro
69. autonomous baby sitter of sorts incorporating Baby peas in daily life will improve the quality of existence for both the infant and the caretaker This document summarizes the thought process behind designing the Baby peas system in terms of medical background hardware and software solutions Section 2 details the motivations behind the project and lists out the primary objectives In addition this section gives the preliminary parameters for unit operation including battery life physical packaging of device sensor accuracy targets wireless transmission range and operating temperatures Section 3 seeks to flesh out the background of the unit in three categories existing examples medical principles and technological offerings Starting off with existing projects similar to the Baby peas unit primarily the owlet care sock and the KnightTime project for University of Central Florida s senior design during Fall 2012 and Spring 2013 the chapter then moves to other market share units which are conventional baby monitors offered by such major health care companies like Philips The latter half of section 3 investigates the relevant medical understanding underlining infant health markers and also the technologies involved in monitoring those bio markers such as temperature or pulse ox sensors Finally this segment s last half ends with discussions on the choices for communications mobile applications the central microprocessor and power syst
70. ayers that are typically manufactured with indium tin oxide 52 99 Transparent Conductor ITO Bottom Side Transparent Conductor ITO Top Side X Conductive Bar Insulating Material Glass Figure 64 Resistive Touch Screen Reprinted without alteration with permission from Texas Instruments The base layer is called the matrix a layer with stripped electrodes in a pattern while the second layer is called the analogue a layer with transparent electrodes As the user draws their finger across the screen the layers touch at the figure junction and complete the circuit at the point causing a differential in the system The primarily mode of sensing 1S pressure so a resistive touch screen can be used by any object such as human finger pen or pointer The coordinates of activity is sensed using two industry standard the 4 wire and the 5 wire configuration Figure 66 shows the two typical layouts 52 FAN T E 4 wire 5 wire Figure 65 Resistive Touchscreen Layouts Reprinted without alteration with permission from Texas Instruments Resistive screens are the cheaper of the two touch screen options and have higher resolution often being used in handwriting recognition capacity In addition as discussed earlier any object can be used as the pen However it does have some disadvantages including less responsive to the pressure of touch Because the top layer 100 is being pressed down into the bottom la
71. be subtracted External 8 MHz crystal generates the frequency responsible for controlling the clock cycles 4 MHz is used for timer modules ADC and the diagnostic The detailed pin configuration can be seen in figure 9 To integrate AFE4490 with the microprocessor a basic understanding of pin function is necessary The pins can be put into five categories based on functionality Each category is summarized in table 8 Note the tables do not contain all the pins but the pins which are used or discussed 31 PIN CONFIGURATION RX_ANA GND RX ANMA SUP RX OUTP RX DIG GND RX DG SUP XIN XOUT CLKOUT ADC_RDY SPISTE SPISIMO SPISOM SCLK PD_ALMIADC Rese LED ALM l l l l l l O A O 21 DAG END Ea k W A q 1131 141 15 1181 177 18 Hi MP GND LED DRY SUP TX_CTRL_SUP LED ORV GHO LED DRY SUP LED ORV E Figure 9 Pin Configuration of AFE4490 Reprinted without alteration with permission from Texas Instruments 3 3 1 1 Analog Pins Pin 1 and 2 are analog pins connecting the photodiodes with wavelength 660nm and 940nm with analog ground common ground pin 3 36 and 40 Block diagram and pin connection will be discussed in hardware section 4 1 1 No INP 2 Receiverinput connected to photodiode cathode LED driver out B H bridge output connected to LED LED driver out B H bridge output connected to LED Table 8 Analog Pins and Descr
72. ce and parasitic capacitance and inductance create reactive impedance that varies with frequency For the first point the capacitance formed between two conductors is given by the equation q y C capacitance q charge V voltage Inadvertently capacitance can be formed from parallel trace runs or by traces over a ground or power plane 46 In addition the wires running the power throughout the circuit also create capacitance The general inductance formula is given by 46 uN A L l u the magnetic permeability of the material A the cross sectional area of coil the length of the solenoid In addition the normal use intended induction parasitic inductance effect is given by 45 1 Z j E wLparasitic Z total impedance w omega C capacitor value Lparasitic parasitic inductance Utmost care must be taken in the satellite unit to rid of any preventable noise As the module is quite small and low powered any noise can have a catastrophic effect on proper operation 3 2 9 1 4 Electrostatic Discharge Protection Finally a mention of electrostatic discharge is in order to the sensitive nature of the components Working with open boards is a recipe for disaster without proper ESD protection schemes Table 6 shows the minimum volts that can start to damage the devices 26 ESD susceptibility threshold V Table 6 ESD thresholds for common devices 48 The values might seem high but the
73. ce to the inexperienced group members 110 6 Project Prototype Testing 6 1 Hardware Prototype Testing Hardware testing needs to be thorough methodical and controlled for the Baby peas project to be successful unfortunately due to time constraints the following testing was not entirely completed or thoroughly incorporated Hardware testing can make or break a project There is a fine line between how much a company should spend on testing hardware and software before releasing products to market Testing costs companies money and for every day the product 1s not on the shelves is more money the company 1s losing However projects also realize not enough testing can lead to product failure in the field which can be detrimental in the long run for the survival of the company The Baby pea s project is opting for an abundance of test scenarios because of the nature of the product Since safety is of the utmost concern any failure on the device which could cause even the slightest amount of harm to the individual is unacceptable The project specifications must be met and back up protection code and hardware must be put in place to allow for as many possible scenarios which could cause harm to the user are explored In addition testing parameters must be calibrated with the baseline set for infants and not adults In the following sections a comprehensive hardware and software test matrix will be provided as to cover each sub system and full sy
74. ces The pin out diagram is shown in Figure 64 To use the full packet sniffer capabilities of the debugger the SPI bus must also be connected to the SoC device The SPI bus is used to read RF packets from the SoC device The CC2541 can also configure its RF SoC to operate as SPI slaves through one of the USART terminals The TI SoC devices only support two pin configurations to act in this manner USARTO altl USARTI alt2 The CC2541 supports the USARTI alt2 configuration Table 24 shows the pin out details of this configuration The CC debugger will be connected to the CC2541 in this manner and can be referenced back to the schematic diagram in Figure 48 and 50 GND Target Voltage Sense DC Debug Clock DD Debug Data CSn SPI Chip Select SCLK SPI Clock RESETn MOSI SPI Data Out 0 3 3V from debugger MISO SPI Data In ip i Figure 63 CC Debugger Target Connector Pin Out Reprinted without alteration with permission from Texas Instruments USARTO alt1 USART1 alt 2 Table 24 USART Pin Out Details Reprinted without alteration with permission from Texas Instruments 4 1 5 User Interface Design As the most visible aspect of the product having an instinctive experience for the user interface is a huge advantage A clunky user experience can kill an application in its infancy In particular in the case of a baby monitor experience flow is paramount to the 98 entire operation With important aspect
75. ces and their respective parameters of importance pertaining to the baby pea s project nput Voltage volts RX current 250 kbps 500 kbps 1 Mbps 2Mbps 1 Mbps 2Mbps 2Mbps module combined module combined Table 16 Bluetooth Device Comparison From Table 16 we derive HC 06 to give us the greatest output power but at the cost of a much higher transmit current consumption One of the downsides of the HC 06 is it doesn t have a build in microcontroller Also the documentation from the data sheet is extremely confusing because there are several different revisions with all different configurations The differences between the nRF51822 and CC2541 are very small The nRF51822 has a slight advantage over the CC2541 in cost current draw but has a slightly larger package size Since the two devices are very similar in design the Baby Peas project decided to go with the CC2541 for a different reason Texas Instruments has a wealth of information and application notes to help users starting new projects to come up to speed on Bluetooth Low Energy rather quickly They offer many example projects in both the hardware and software aspect Texas Instrument also has an evaluation kit which incorporates six different sensors integrated with a CC2541 package with all relevant information included for 20 00 Sensor Tag The evaluation kits for the nRF51822 start at 100 dollars with less examples and documentation So the CC2541 from Texas Instruments s
76. come deleterious Just like the harmless feeling of sunbathing thermal burns sneak up on the user and can have devastating consequences In fact there have been cases of serious burns caused by overheating battery packs of laptops Those incidences involved adults that received the burns unknowingly over a period of hours as they used the devices on their laps and in contact with their legs Table 5 shows the gradual gradation between the comfortable temperatures to temperatures that can cause irreparable damage A baby would be much more susceptible to thermal agitation on its skin Along with slow heating the different types of batteries have levels of volatility The battery type chosen must have long stable life with little to no risks in explosions In addition to when the unit 1s used against the user s skin the charging portion deals with addition risks as it is going to be connected to a wall socket with the potential of 120 volts The charging station will need an adequate charging unit with transformer to step down the voltage to the acceptable amount for the circuit With adequate circuit protection component selection and circuit board design these challenges should pose no issue in the final product 3 2 9 1 2 Operation After safety the second design consideration deals with operation To fully realize the potential of this unit a priority lies in length of operation and recharge ability of the unit 24 Body Temperature Si
77. ct line Verifies accuracy and operation of the SCL should measure chip select line active SDA and SCL lines with an O clock frequency from the CC2541 on the clock frequency high scope to verify clock frequency the SCL Ime and verifies SDA high low output from CC2541 SCL and verify SDA Data transitions the data is being ouput from SDA should be a the TMP006 sqaure wave SDA SCL line test Measure the chip select line Verifies when chip select line is active chip select line to be chip select line active SDA and SCL lines with an O low the TMP006 should be off and low SDA line to be low scope SDA output data should be either constant high or always high or always low constant low Table 28 TMP temperature Hardware Test Matrix 112 6 1 1 2 Body Position Sensor Hardware Once the TMP006 hardware device is tested the next device to be placed into circuit will be the MPU 6000 body position sensor First the TMP006 will be disconnected from the circuit The MPU 6000 will then be installed and tested in the same manner as the TMP006 Since both devices interact with the Atmega328p over IC the device testing characteristics will be the same as shown in Table 28 with the difference being the device name 6 1 1 3 Pulse Oximetry Sensor Hardware The pulse oximetry sensor hardware circuit is tested next The temperature sensor TMP006 and the MPU 6000 can remain in circuit except for their input voltage Their data lines inter
78. d 53 USART serial interfaces for data transmission One of the advantages of the CC2541 is its compatibility with the TPS62730 The TPS62730 is a 2 MHz Step Down converter with a bypass mode The step down converter takes the input voltage and reduces it to a lower voltage for low power uses The TPS62730 extends battery life by up to 20 percent and reduces current in all active modes The Bypass mode provides a 30 nA current to support low power modes The Bypass modes do not affect the RF performance of the Bluetooth module The CC2541 has multiple low power settings that operate on a voltage range of 2V to 3 6V The low power Active Mode RX operates at 17 9 mA and the Active Mode TX 0 dBm operates at 18 2 mA Power Mode 1 operates at 270 uA with a 4 us wake up time Power Mode 2 operates at 1 uA with the Sleep Timer on and Power Mode 3 uses 0 5 uA with external interrupts The TPS62730 Step Down Converter is on in both active modes The CC2541 is available in a developmental kit called the Sensortag The Sensortag comes with a CC2541 interfaced with a number of sensors The developmental kit will provide a great source of reference material when designing the project 24 Advantages of the CC2541 e Bluetooth System on Chip solution e Sensortag development kit allows valuable reference design e TPS62730 capability affords ultralow power e 8051 MCU architecture e High processor speed e Sufficient memory space 3 3 7 5 MSCI210 The MSC1210 i
79. d Numbers as the Chosen for Baby Peas longer battery life and less thermal dissipation Oy ce at ees aaa as Sr ST yon ai am A U Vour 3 3V L 2 2 uH LPS3314 2R2 Cou 10 uF 0603 40 0 001 0 01 100 1000 pre Sed e Figure 34 Efficiency of Regulator with Different Output Current Reprinted without alteration courtesy of Texas Instruments Efficiency 67 3 3 8 5 Requirements As discussed above the either a linear or a switching regulator can be used to augment the power coming in from a battery Also discussed prior the battery unit can be either coin packaging or a super capacitor either option could theoretically work It is best to test to see which option does best in the field Requirements for the subsystems Operating Current Voltage Min Voltage Max Gyroscope 3 9 mA 2 375 V 3 46 V Accelerometer DMP MPU 6050 Gyroscope DMP 2 375 V 3 46 V Gyroscope only 2 375 V 3 46 V Accelerometer only 500 uA 2 375 V 3 46 V Table 19 Normal Operating Current for MPU 6050 Other modules ee Current Max Voltage Min Voltage Max Recommended Voltage CC2451 Gyroscope 3 8 mA 2 375 V 3 46 V Accelerometer Tmp006 Table 20 Normal Operating Requirements for Modules 3 3 8 6 Schematics for TPS62740 Figures 35 through 38 shows the schematic and package views of TPS62740 regulator It is important to know the size of the package including height due to the unforgiving size of the
80. determine if the bit is high or low Differential signaling sends two signals across two paired wires called a differential pair The difference between the two signals is analyzed to determine if the bit is high or low 20 The advantage of differential signaling 1s the ability to deal with electronic noise When an electric signal is affected by noise in a single ended transmission the received signal can be misinterpreted due to the change in voltage In a differential pair noise will affect both wire the same Theoretically the difference between the wires should stay about the same so the information sent would be unaffected A bus can also send the data through serial communication or parallel communication Serial communication sends data one bit at a time across the bus Parallel communication sends several bits at a time on parallel channels that are assembled to retrieve the original message Due to cost and complexity most buses are serially communicated Devices may support bus mastering which enables the device to initiate the transfer of data across the bus Depending on the nature of the hardware and software multiple master nodes may be necessary for certain devices 3 2 6 1 PC C is a multi master serial single ended computer bus invented by Philips 3 2 6 2 SPI The Serial Peripheral Interface bus SPI is a synchronous serial data link developed by Motorola that operates in full duplex mode Full duplex implies that the
81. developer sign up fees Android was deemed the best due to the low onetime cost One hurdle is the newness of the Bluetooth Low Energy protocol Android devices being released presently support the Bluetooth LE however android devices released before despite having the necessary hardware do not support Bluetooth LE 101 4 1 5 3 Software diagrams Software High Level System Block Diagram Figure 66 Software Block Diagram These are optional modules If time permits optional modules will be added to the system 102 4 1 5 4 Class diagram Problem statement Need to create a program to gather data sort data and display it to end user The program will be used by the end user to see the status of infant s biomarkers of pulse temperature oxygen level and orientation The program will also alert the user if certain conditions are not met for each sensor Figure 68 below is the class diagrams for the base station monitor Smart Phone DisplayNumericValues DisplayChart device_name String device_address String ScanForDevices AddServices DisplayHistoricinto Temperature Accelerameter raw_data float real_data float raw_dat float real_data float Figure 67 Class Diagram for Smart Phone User interface device data collection parsing and humane computer interaction Class Diagram 4 1 6 Bluetooth Handshake As discussed in 3 2 4 after looking through the different communication protocols
82. dget for the project is maxed out at 1000 dollars While the components and board construction will not approach the cost of 1000 dollars the budget allows for purchasing various development kits to help in the building of the baby peas device The development kits can range from 20 dollars to 300 dollars In the end the project ended up costing a total of 1240 due to the project having to be re directed into using some different components and having to lay out another PCB Also overnight shipping costs caused a lot of undesired cost If this wouldn t have happened then we would have come under budget The group decided to split the cost evenly at 25 of the total cost incurred for a max of 310 00 per individual member 7 4 User Manual This portion of the document is to provide one with the necessary information to take our design and get 1t up and running and ready to demonstrate Below in Figure 72 is a picture of the final design in the Power Off State Figure 71 Baby Peas Vital Signs Monitor in the Power Off State The Baby Peas board is turned on by connecting the pins with a shorting connector to allow for the battery voltage to be applied to the circuit The Green LED on the board should indicate power is on and is shown in Figure 73 To verify the Bluetooth is transmitting one must use an android based phone with Bluetooth capability Since all phones are different version of Android one must follow their user manual for their ph
83. ds through their ovens would be beyond the affordability of the project if the group had to pay for it 5 2 2 2 Conilec Conilec is a local PCB assembly house located in Deland FL They too provide a wealth of services to their customers They assign specific program managers to all their customers and are the point of contact for any interactions between the two parties Conilec will be approached for sponsorship options as well A price quote could not be obtained without a finished PCB layout design 5 2 2 3 DIY Do it yourself The baby pea s project has a certified J STD 001 surface mount solder technician which is able to solder down to 0201 size packages along with LGA and QEN packages The group has obtained a hot air pencil soldering system along with soldering iron equipment for surface mount PCB assembly and a microscope for inspection of solder connections The group has the ability to solder all components onto the PCB and rework each component of the PCB as needed The DIY approach seems to be the best option since the only cost incurred will be solder materials and time but it allows for flexibility in the schedule because the assembly and rework are not relied upon by people outside of the group The hot air pencil will be used for difficult components like the QFN and BGA packages The soldering iron will be used for all other leaded surface mount components In addition the do it yourself approach will give invaluable experien
84. dualized units The first step to query is to use the getBondedDevices call This allows the home device to look for unique media access control address MAC address that is stored in the hardware of the network interface controller In addition to the phone doing the querying the satellite device the peripheral ankle sensor unit can also query for the phone In that case the phone will have to enable discoverability Using the startActivityForResult Intent int and ACTION REQUEST DISCOVERABLE the phone is able to be discovered by the sock unit This is a decision for the designer due to power and timing considerations Figure 70 below is an example of what alert might look like on the smart phone devices once the peripheral ankle sensor unit queries for other devices and the smart phone picks up that query 56 Bluetooth permission request An application on your phone is requesting permission to turn on Bluetooth and to make your phone discoverable by other devices for 300 seconds Do you want to do this Figure 69 Possible alert form and smart phone device reprinted without alteration courtesy of Android 4 1 6 1 3 Connecting device as server side This step is critically important to the communications portion of the unit server side and client side operations must take place on the same RFCOMM channel Server side portion opens with BluetoothServerSocket API and listens to requests for connection Once server side accep
85. e Expensive ari o i hear Overall disadvantages reference required least mes jakas nln Baths plana a power supply stable least sensitive sab ae 9 required required Table 3 Thermo Sensor Technology Reprinted without alteration with permission by Texas Instruments The application requires small form factor in order to be applied to the ankle on an infant Using semiconductor based sensors we can achieve ultra low power consumption with a form factor less than 3 mm 3 2 4 Body Position Sensors Being able to tell what position the baby is in is a critical design specification of the Baby Peas project Position of the baby was at the top of a list of 10 steps to help prevent SIDS from a current WebMD article sponsored by Johnson s baby 35 The CDC 14 Center for disease control states since the 1990 s SIDS related deaths have decreased in the United States by over 50 since the steps to prevent SIDS have been instituted 36 The Journal of American Academy of Pediatrics suggests babies should be positioned on their back while they sleep If the baby is placed on their side or in the prone position sleeping on their stomach then the risk of SIDS is much higher due to rebreathing of expired gases and also overheating Stress is also placed on the baby s cardiovascular system during prone sleeping which can increase heart rates to abnormal levels 37 Since the main goal of this project is to help and aid in the preventio
86. e MPU 60X0 Series csi eninin enine 37 Soe A nalos Device AD XLS 62 ti 38 3 3 4 3 Freescale Semiconductor MMA8451Q uu cece esecceeecceeesseeeeeeees 39 3939 Skin Temperature Sensorial dias 41 LDL A O 41 o A A E G 46 33 6 COMIMUNICALIONS Sensor aii atea les ida a dde dales 47 IGL CEZAPFBERSOO tenor na rn 48 330 2 HE 06 Bluetooth Moodle iaa 49 5257015 ARFS DLE Module ida 49 Sd INMCrOCOMIOlEL serias icid ds 52 232 EEMS P4530 ERAM SES eena a oie 32 Deals ATME Deere deen deetaubounedustesecabecdeetacscuabudeety 53 Ss PIC VICK O iii 53 de CO eS 53 B ISC daa 54 SO POWE SUP a 55 SO Bay aaa mu 55 IIS ACPOWErSUPP ye a a aneee 59 OO DC PONES UPV td tenons 55 o A a a a a ar 59 E O 56 398 Board supply Re Sul ator anni 56 3 3 8 4 1 Linear Regulators Linear Tech LT1761 c ooononnnnnnnnnoninnnnnonnnnns 56 3 3 8 4 2 Switching Regulators Texas Instruments TPS62740 0 58 555 642 21 IPINPEUNCUIONS ii ais ea 61 3S3 REQUITEMIENLS in 68 32300 schematics Lor TPSO2 MO se 68 4 Project Hardware and Software Design Details cccccccnnnnnnncncnnnnnnnononnnnnnnnnnnos 70 4 1 FAI Wu ii 70 All Polke Oximeter Sensor Deseo toi orita dada 71 Asked Body Position Sensor DES i n 73 4 13 Skin Temperature Sensor DOS A it 74 4 14 Communications Microcontroller Design ooooocccnnnncnnnnnnnncnnnnnnnnnnnnnnnos 75 AAA COMMUNAICAIONS tt 75 4 1 4 2 Microcontroller CC2541 Design characteristics
87. e frca co uk gt Subject AnaesthesiaUK Web Site Feedback gt gt We ve had feedback from the following person via the enquiry section gt gt Name Yowwu Lin gt E mail wasiasd hotmail com gt Feedback Hello would like to request permission to use the graph on gt pulse oximetry on my research paper for school Thank you for the gt information Please respond to wasiasd hotmail com 4 http www howequipmentworks com physics respi_measurements oxygen oximeter pulse_oximeter html From pras2 onvenus com To wasiasd hotmail com Subject Hello Date Sat 23 Nov 2013 10 04 59 0000 Many thanks for your kind donation The pulse oximeter diagrams are rough sketches of the real thing However believe it should be adequate for your school project and please fell free to use them When finished do email me a copy if you can for my curiosity Good luck Pras De 137 Rod Nave lt RodNave gsu edu gt Sun 11 24 2013 3 20 PM To x tong lt x tong knights ucf edu gt Action Items Hi Xin You are welcome to use anything from HyperPhysics for the purpose of your academic assignments Best wishes with the paper Regards Rod Nave RodNave gsu edu HyperPhysics Project Department of Physics and Astronomy Georgia State University Atlanta GA 30302 4106 6 Google android development content Except as noted this content is licensed under Creative Commons Attribution 2 5 For details
88. e is no constant supply of power this helps to prevent the waste of power The advantages of switching regulators are efficiency longer battery life and less heat dissipation and size While switching regulators often require more components than linear regulators the fact that switching can forgo the heat sinks that are a staple of linear 58 regulators Some of the disadvantages of switching are a higher cost compared to linear and the introduction of more noise In addition switching regulators often require a little more complexity in circuitry and will need inductors to act as an energy storage element and external diodes The disadvantages of noise can be ameliorated by using families of ultralow noise regulators For example Linear Technology offers packages such as the LT1533 Designed specifically for sensitive instrumentation measurements and medical devices this regulator is designed so that the noise generated by the frequency of the switch duty cycle will not interfere with other modules on the board TI s Bluetooth sensor tag uses a switch regulator the TPS62730 Key Features e Input Voltage Range from 1 9V to 3 9V e Typical 30 nA Ultra Low Power Bypass Mode e Supports sleep and low power modes on CC2541 e Typical 25 uA DC DC Quiescent Current e DC DC converter connected via typical 2 10 Bypass switch to battery The TPS62730 is a step down DC DC buck converter Figure 26 below shows the typical battery current of the CC2540
89. e output RF power from the system to verify proper gain flatness is maintained over the entire transmit frequency band Software settings within the CC2541 can program the different transmit output power settings Tests will be conducted which check the Max Mid and Min output power settings Also two external crystal oscillators are being used which need to be verified as operational Table 30 below displays the test matrix for the CC2541 circuitry portion While the CC2541 was not used in the end this text matrix was somewhat implemented For the HC 06 output measurements could not be taken due to the difficulty of being able to solder into the transmit circuitry The HC 06 was also not configurable on output power so the only test was making sure data was streaming out and this was verified by the phone app being utilized 113 Test Procedure Description Expected Result 1 Output Power Test RE_N pin Max Power 2 Output Power Test RF_P pin Max Power 3 Output Power Test RE_N pin Mid Power Output Power Test RF_P pin Mid Power RE_N pm Low Power Output Power Test Output Power Test RF_P pm Low Power 7 32MHz crystal oscillator Test 32 768 kHz crystal oscillator Test Usmg a Spectrum Analyzer and RF probe check RF_N pin during transmit TXPower Mode set to OxE1 Using a Spectrum Analyzer and RF probe check RF_N Using a Spectrum Analyzer and RF probe check RF_N pin during transmit TXPower Mode set to 0x91
90. eck position one can flip the board back and forth from once side to the other and observe the Position will go from safe to danger depending on which way the PCB 1s orientated Y Pulse 18 Object Temperature 72 F Position Safe QV de Q Back Connected Rotate Figure 74 Screen shot of the application showing data 7 5 Conclusion In the end the Baby Peas project didn t necessarily have a working product able to be strapped onto an infant but a proof of concept was designed in order that with enough funding and a lot of software development help the baby peas project could be developed into a product in the future The team members learned a lot from this experience not just in designing a product but working as a team to solve the challenges they faced When the CC2541 design approach wasn t working out a quick solution had to be realized in a very short amount of time This is why the team decided to go with an Arduino based design because the skills required to embedded code for the CC2541 were not enough to 127 overcome some of the hurdles faced While the hardware worked great configuring the CC2541 proved to be extremely difficult and the IAR embedded workbench licensing was a nightmare In the end the product did was we set out have it do It provides vital signs information to a person over wireless communications which could provide an early warning capability to another person which could save a life 8 Appendice
91. edge of the debug clock When the reset pin is pulled high again there is another pause before the first rising edge of the clock Time DEBUG CLK P2 2 RESET 7 td _ i t pi 5s Figure 60 Timing Characteristics of the Debug Clock Reproduced without alteration with permission from Texas Instruments Figure 62 below shows the data signal characteristics of the debugging system The debug data is setup on the rising edge of the debug clock The setup time of the debug data originating from the CC2541 is shown by the term t The next term t7 shows the hold time that the data must remain at a constant level in order to be successfully read by 96 the system The data is read on the falling edge of the debug clock The last term tg shows the delay time from the rising edge of the clock to the end of the data bit Time i DEBUG CIK l P22 DEBUG DATA lo 0002541 P2 1 DEBUG DATA fom 002541 l P2 1 a ts gt t la Figure 61 Timing Characteristics of the Data Signal of the debugging system Reproduced without alteration with permission by Texas Instruments Figure 63 below illustrates a typical debug command sequence The command byte is read by the debug interface to configure the debugger Data bytes are then read to the system
92. eems the most logical to incorporate as both the RF module and Microcontroller for the baby peas project Towards the end of the project the CC2541 proved to be much harder to implement than was thought To program the CC2541 and develop on it the IAR embedded workbench design environment must be used IAR 51 embedded workbench costs around 1500 dollars for a student license They do provide a 30 day full trial period with unlimited code size and free version which is code limited to 4kb The problem arose when all of the sample projects were over 4kb and our free 30 day trial was about to expire Also problems arose with the version of IAR that was to be used The current version does not compile the TI provided current BLE stack but IAR does not mention this We found out after a week of troubleshooting that an older version of IAR embedded workbench must be used to use the BLE v4 stack from TI With time running down to providing a working project the Baby Peas design bailed on the CC2541 and implemented the HC 06 with an Atmega328p utilizing the Ardiuno Development environment This was much simpler and allowed us to redesign our project very quickly 3 3 7 Microcontroller The microcontroller is an essential part of the overall project The function and data flow of the sensors is determined by the microcontroller The data originates from the sensors and is passed on to the microcontroller through its input output system When selecting the a
93. ems In this section all of the chosen strategic components are listed Section 4 delves hardware and software design details including each sensor chosen the microcontroller CC2541 the power systems and mobile application In addition to those modules the discussion includes how data transfers between each module and includes serial protocols such as I C and SPI Unit 5 lists companies for printing the designed circuit board and in addition lists options for populating the printed board Once the board is made and populated section 6 inventories prototype and system level testing The prototype testing provides a listing of each sensor test taking care to isolate each system and targeting each system specifically before a general integration test After ensuring the viability safety precautions and robustness of the unit a final test commences on each group member This document finishes with chapter 7 a section on general milestones for senior design 2 which is the next step in building Baby peas and also the budget finance discussion and the roles and responsibilities of each member in the group 2 Project Description 2 1 Project Motivation and Goals Markets sell a variety of baby monitoring equipment that includes an abundance of features some common features include infrared cameras and ambient temperature sensor While many traditional monitors focus on the video as a safety feature a baby s wellbeing is sometimes hard to dec
94. enient real time updated vital signs of their babies Each vital sign related to the Baby Peas project will be discussed in the following sections 3 2 1 3 1 Skin Temperature Sudden onset of fever in the newborns caused by a myriad of factors such as system infection dehydration and physical surroundings has caused many parents sleepless nights The immune system in the infants is not fully developed until around six months of age In addition as mentioned above hyperthermia and hypothermia can be factors leading to SIDS It is crucial to monitor the temperature in order to make necessary medical evaluation and interventions A thermometer measuring the babies temperature continuously can do just that Many possible causes can make the temperature to rise in the infants and nearly all of them are signs of a systematic response The most common cause is infection whether it is viral or bacterial When the body encounters foreign microorganisms the immune system will try to fight them off with antibody responses or produce more leukocytes Part of the immune response is to raise body temperature since certain bacteria and virus cannot withstand a higher temperature environment Pyrogens are responsible for raising the body temperature by interacting with the hypothalamus region of the brain Moreover dehydration is another cause for fever Water has a very high specific heat and can absorb very high temperatures or conserve temperature As suc
95. ensor on Verifies the sensor will be User display should show table top and utilize a heat updating the user display rising temperatures gun to heat the sensor with increasing temperature readings Place peripheral sensor on Verfies the sensor will be User display should show table top and spray the updating the user display decreasing temperature sensor with a freeze spray with increasing temperature readings 5 User Interface Alarms Place peripheral sensor n Verifies as a temperature Alarm sounds if environmental chamber and changes by 5 degrees tt Temp A 5 degrees from set chamber to 25 degrees causes an alarm on the baselined temperature C Once stable set user mterface display readings Baseline Temp 25c temperature to 30 degrees device adroid phone Alarm sounds 30c and C Repeat at 25 degrees C 20c Table 33 Skin Temperature Final Acceptance Test matrix 6 3 2 Body position Final Test The body position final acceptance testing will be performed in a lab environment with no need to be attached to a user The peripheral sensor will lay on a flat surface and be orientated in different angles to observe accuracy of position along with alarms on the user interface device when moved into different positions Also being tested is a settling time check This test allows the user to receive a notification symbol MOV stating the 117 infant is moving and cannot obtain a steady reading for body position Si
96. eping everything else the same the core consumes 20 2 mA In TX mode and 20 dBm output power the core current is 16 8 mA At 0 dBm it is 18 2 mA For general low MCU activity the 32 MHz XOSC is running with limited flash access No radio or peripherals are active and RAM cannot be accessed The current consumed is 6 7 mA Power mode 1 implies the following the digital regulator is on the 16 MHz RCOSC and 32 MHz crystal oscillator is off the 32 768 kHz XOSC POR BOD and sleep timer is active RAM and register data is retained The current consumed is 270 uA Power mode 2 implies the following the digital regulator is off the 16 MHz RCOSC and 32 MHz crystal oscillator is off the 32 768 kHz XOSC POR and sleep time are active RAM and register data is retained The current consumed is 1 uA Power mode 3 implies the following the digital regulator is off there are no active clocks the POR is active RAM and register data is retained The current consumed is 0 5 uA Peripheral current usage of the cc2041 adds to the core current when the peripheral unit is activated The analog to digital converter uses 1 2 mA when converting Timer 1 4 runs with the 32 MHz XOSC Timer 1 uses 90 uA Timer 2 90 uA Timer 3 60 uA and Timer 4 70 uA The Sleep timer includes the 32 753 kHz RCOSC and uses 0 6 uA The output power of the device is associated with a typical current consumption When the output power is O dBm the current consumption is typically 18 2 mA
97. er s ankle turning the device on opening up the application and choosing the monitor my child option This 1s the main monitoring display and will display all 4 sensor data The development kit Sensor Tag device will also be mounted to the user very close to the project peripheral device The Sensor Tag development kit utilizes the same sensor device in the Baby pea s project The sensor tag will be wirelessly connected to a laptop where a user interface GUI will be running displaying the sensor tag s skin temperature readings The sensor tag is a known good device and we can use it to compare the data displayed from the sensor tag to the data being displayed from the baby pea s peripheral device Table 33 is the test matrix to verify the Skin temperature sensor meets project specifications Test Procedure Description Expected Result 1 Skin Temperature of User Attach peripheral and Verifies the proper Baby peas peripheral and in Ambient Room Temp sensor tag to user ankle and reading of the skin sensor tag sensors are within power on both assemblies temperature 5 of each other 2 Skin Temperature of User Attach peripheral and oral Comparison test between Baby peas s peripheral in Ambient Room thermometer to user and oral temperature and skin should read within 10 o compared to thermometer compare temperature temperature oral temperature data taken orally results 3 Increasing temperature Place peripheral s
98. es have shown the importance of sleep in cellular regeneration and waste product removal It is important the brain gets rest and energy gets restored 1 In particular in babies due to rapid cellular growth and brain development REM sleep can have lasting impact on overall health of the baby throughout his her lifetime 3 2 1 1 Infant Sleep Cycles For the first two month of life the sleep cycles are varied around the clock and may even interfere with mealtime and diaper change In addition infants are quite mobile and may appear to be restless during sleep Parents often learn what the babies want by associating certain gestures to the need In addition parents can help the infant adjust to a normal circadian cycle by introducing regularity and patterns Parents can encourage nighttime sleep by dimming the lights in the evening and reducing the ambient noise level This signals to the baby that sleep is imminent and will train the baby to form a Pavlovian response On the other hand parents may try to stimulate the babies with lights and noise to keep them occupied during the day forming the opposite Pavlovian response to night time 2 From age of three months to one year old sleep will be more regulated as the infant will tend to sleep through most of the night The infants will take between one to four naps during the day each of which can last from thirty minutes to two hours At this stage of life the infants may become attached to the
99. fication but the protocol is no longer controlled by IEEE 802 but instead is run by the Bluetooth Special Interest Group This group is made of over 19 000 members in the consumer electronics industry 34 Bluetooth works in the ISM band of 2 4 GHz It uses frequency hopping spread spectrum technology which can help in the avoidance of interference of other ISM devices transmitting in the 2 4GHz spectrum It uses GSFK Gaussian Frequency shift keying modulation and supports all Network topologies Mesh does need special application enabling Bluetooth is especially designed for low power consumption Its range depends on different protocols and individual setups but can vary between 1 meter to 100 meters This meets our specification limits for range Components are very low cost and the design parameters for Bluetooth are geared towards a quick time to market approach This is good for the baby peas since we have a limited time constraint for development Bluetooth is also prevalent and almost all cell phones laptops and tablets Bluetooth is also certified and one of the preferred technologies being pushed by the non profit organization Continua Health Alliance which seeks to set industry standards for health technologies There are two different protocols to discuss dealing with Bluetooth which are Bluetooth Classic and Bluetooth LE Low Energy 34 3 2 5 1 1 Bluetooth Classic Most of the specification for Bluetooth classic 1s already covered in
100. for non energized work Remember to take adequate precautions when working with live circuits as discussed in part 3 2 9 1 1 21 3 2 9 2 AC Power The AC power component is primarily used for recharging the power supply for the unit In the alternating current source in order to be able to use the potential components like transformers rectifiers filters and regulators needs to be incorporated After the Transformers help to step down the 120 240 AC down to usable voltage for the power supply rectifiers in formations such as a full wave rectifier help to covert the sinusoidal supply to a rectified waveform This rectified waveform is smoothed out by the filtering capacitor Figure 5 Simple rectifying circuit An example circuit Figure 5 shows how an incoming sinusoidal wave is stepped down at the transformer and then rectified at the bridge rectifier made of four diodes and finally smoothed out by capacitor Cl The output of this circuit is a direct current at a usable voltage In the baby peas unit this DC voltage is used to charge the rechargeable battery Figure 5 is an over simplified unit and lack any sort of circuit protection Fuses will need to be incorporated to protect the circuitry While it is theoretically possible to build an AC power supply unit for this project it is recommended to forgo this subsystem due to extreme hazards of working with live mains power Without Occupational Safety and Health Admiunistration
101. frequency range e Low data rates Vendors moving away from supporting Difficult to implement 3 2 5 4 ANT ANT ANT and ANT are proprietary wireless protocol sensor networks Its main applications are for sport and home health It also operates in the 2 4 GHz ISM band ANT products come preloaded with protocol software packages and are controlled through UART SPI or USB It has low power consumption and can operate on a coin cell battery It can support all network topologies There are 8 channels and they are bi directional It uses adaptive isochronous network technology to avoid interference with other household products transmitting in the ISM RF spectrum Data rate is 20kbps Range is 30m 33 30 Pros e Uses all Network Topologies e Low power consumption e No sensor slave limit 19 e Extremely fast transmit time Cons e Not all new smart phones support ANT ANT Lower Range Low Data Rate Usually transmits on a single channel for each device If that particular frequency is not free within the band it halts data transfer and could potentially have packet lose 3 2 5 5 Zwave Z wave 1s another proprietary wireless technology aimed at home automation It operates in the 90OOMHz range Z wave uses low latency communications of small data packets The data rates are around 100kbps Its range 1s around 30m It uses a mesh network topology and its modulation mode is GFSK 31 Pros e Low power consumption e Up to 232 devices o
102. g the TPS62730 DC DC converter The red bar shows the current consumption with the CC2541 connected to the TPS62730 DC DC converter in ON mode For increasing voltage the current consumption with the DC DC converter on steadily declines The vertical axis on the right side is labeled for percentage of current savings This is the percentage of current decrease depicted in the red bar with respect to the blue bars The current savings steadily increases with increasing voltage This indicates that there is up to 37 percent decrease in current in transmission mode and up to 35 percent decrease in current in receiving mode This overall decrease in current in both modes will lead to a much longer battery life as compared to the blue bars which show an increase in current with its associated increase in input voltage It stands to reason that without using the TPS62730 the battery life will be approximately one third shorter than the alternative While the TPS62730 is used in TI s sensor tag the regulator recommended for this project is the TPS62740 Current Consumption TX 0 dBm Current Consumption RX 5G 25 E A OxBF 20 EA Current mmm cE al 20 ES Current TIT i Current mA Current Savings Current mA E Current Savings 3 At 2 1 2 4 2 T 3 3 pa v Supply M Figure 27 Current Consumption in TX and RX used with permission from Texas Instruments Figure 28 below shows an example application of the TPS6270 co
103. gh a framework called Cocoa Touch This controls the actions of the touch screen interface and its interactions with the operating system Applications for the 105 are usually programmed in a C language C C C Zi 3 2 7 2 Windows Phone Windows is the operating system developed by Microsoft and is used in most Microsoft products including many desktop computers smart phones and the Xbox The latest version of Windows is Windows 8 Many programming languages are supported by Windows Store apps These include Java HTMLS C Microsoft Visual basic XAML Extensible Application Markup Language Visual C component extensions C and Microsoft DirectX The development environment used for Windows is the Microsoft Visual Studio Express 2013 It includes the Windows Software Development Kit Blend for Visual Studio and a device simulator to test out the Windows Store apps that are created There are available templates for beginners to understand the basic structure of an app Windows has also developed a cloud computing platform called Azure which provides both platforms as a service PaS and Infrastructure as a service laaS 3 2 7 3 Android Android is an operating system based on the Linux kernel Android is owned and developed by Google After an update is released the operating system is open sourced and allows the Android community and consumers to alter and add on to the operating system where new features and improvements can be
104. gns and symptoms degrees Fahrenheit 100 110 Brain Damage fainting nauseous feeling 98 6 Normal body temperature 90 98 6 Shivering and goosebumps 80 90 Lose power of speech 70 80 Potentially irreversible cooling 60 70 Lowest temperature with recovery lt 70 Irreversible recovery Table 5 Physiological reactions to body temperature 47 Designed to last 8 hours a day Baby Peas will give the caretaker sense of security in its quality performance without the interruption of charging and exchanging out units Each sock unit should last a day s worth of monitoring In addition to the battery life of a day each unit should also be recharged within a reasonable amount of time This 1s to ensure quick overturn term if needed and give flexibility to the user whether at home or on vacation In addition each time the sock is exchanged out would mean device wearing which can prematurely lower life time usage This is in addition to the issue of weight and scale All of these need to be considered when searching for the portable DC supply Some viable options include AA batteries button batteries or super capacitors Super capacitors are a very attractive option They have rapid recharge time have less wear with constant recharging and discharging and function well under different temperature variations They are also extremely stable as they use stored static charge rather than energy from chemical reactions Lithium ion when ex
105. good choices If the project basic goals are met and the decision is made to focus on a stretch goal either monocyrstalline or polycrystalline would be a good choice It is recommended that the decision be made on the side finance and polycrystalline be the choice due to its lowered costs and comparable characteristics with the monosyrstalline offering In addition there is a breaking in period for the cells There are many available schematics for simple solar cell phone charger The voltage for a phone is around the voltage needed for the module so a solar charger is a very viable option Several issues to consider in designing the solar unit Solar panel collapse Figure 7 shows the solar cell I V curve in varying sunlight At each level there is an optimal power point Following the red line at a certain point any slight increase in current will cause the voltage to drop to 0 The maximum amperage is 0 034 A At the second line a lighting condition less optimal than the first line the maximum amperage is 0 026 A So imagine if a solar charger is operating at full sunlight and supplying the maximum amperage of 0 034 through the circuit any changes in lighting condition without changes in the current draw would immediately drop the voltage down to 0 57 29 Solar Cell l V Curve in Varying Sunlight Figure 7 Provided by the openware documentation from Adafruit industries shows an current voltage curve of solar cell pe
106. h along with the hardware section during hardware prototype testing Since the embedded code will be split up into separate function operations for talking to and sorting data from each sensor at different times the software code can be commented or uncommented depending on which functions are needed for each specific sensor device Table 31 is a walkthrough of the individual tests which will be run to verify the software code loaded on the CC2541 is functioning properly Test Procedure Description Expected Result 1 CC2541 hardware init is Use IAR embedded Verifies the ability to Code compiles with no compiled and properly loaded workbench to compile code compile and load code errors compiled code onto CC2541 and load onto CC2541 onto the CC2541 loads successfully onto CC2541 TPS62740 interactions and verify soft start of the code TPS62740 TPS62740 is operating per TPS62740 voltage operating correctly Test Matrix Table X regulator for proper operation o for enabling TMP006 Compile TMP006 function Verifies the enable and No errors in compiled E for enabling Compile TPS62740 function Verifies the enable and No errors in compiled interactions and verify soft start of the TMP006 code TMP006 TMP006 is operating per voltage regulator for operating correctly Test Matrix Table X proper operation 6000 function interactions and soft start of the MPU code MPU 6000 verify TPS62740 is 6000 voltage regulator for operating correctly o
107. h support the 802 11 standards Some of the concerns with WI FI are the high power consumption and ease of implementation 30 Pros e High Data Rates e Less interference if transmitting in the 5GHz range 18 e Compatibility with most consumer electronics e Exceeds Range specifications for project e Protocol support plentiful e SOC system on chip solution Cons e High power consumption e A lot of interference at the 2 4GHz range Not so easy to implement 3 2 5 3 ZIGBEE Zigbee is a wireless technology suited for low power consumption applications It is maintained under the IEEE 802 15 4 standard Its main applications are wireless control and monitoring which is exactly what is needed for the baby pea s project Zigbee uses mesh network topology which basically means there is one Master and many slaves but the slaves can relay messages from one to another If one of the Zigbee devices breaks down it s still possible to get the data received or transmitted by another Zigbee device handling the data Zigbee operates in the ISM band of 868 MHz 915 MHz 2 4 GHz Transmission data rates are around 250Kbit s for the 2 4GHz frequency range and max ranges are around 20m which is a problem for the baby pea s project Zigbee operates on 16 channels which are 2Mhz wide and 5Mhz apart 31 Pros e Low power consumption Cons e Does not use frequency hopping which could cause interference with most household devices using the 2 4GHz ISM
108. h water is critical in maintain homeostasis When the infant is dehydrated the body is unable to regulate temperature efficiently and thus body temperature can spike An adult might be able to deal with dehydration more efficiently due to the larger quantities of water but an infant has a much more limited amount of storage for water Identifying the cause of dehydration in a timely manner is crucial In addition to dehydration and infections wrapping the babies with too much clothing may raise the body temperature as well Infants are fragile and any measures are usually amplified by a magnitude so the caretaker needs to be every vigilant 3 A few ways to measure infant s temperature are rectally or orally While taking the temperature rectally gives the most accurate results it is inconvenient and may be irritating to some babies Measuring oral temperature is not recommended since it requires the closure of the mouth and under the tongue for accurate reading It could also be unsafe to stick object into an infant s mouth Using ear thermometer may also be irritating and the accuracy could suffer under certain condition such as excessive ear wax Some hospitals policy to measure temperature is using temporal artery thermometer While it s easy to use on adults 1t does not necessary apply to infants until they reach three months old Measuring temperature using regular thermometer under the armpit axillary temperature is easy convenient
109. h will be easier to use along side with the temperature and body position sensor Compare AFE4490 to a self designed analog front end AFE4490 offers many additional features such as current fault detection While AFE4490 may increase interface difficulty because of the SPI interface it does not require any additional hardware With AFE4490 single chip solution it may benefit Baby Peas monitor for increased accuracy and reduced hardware modulation The price of a single AFE4490 is lower than using multiple chips with different functions In the end the discrete design was implemented due to the complexity of using the AFE4490 Using a discrete design cut down on complexity and ease of troubleshooting when problems arose Discrete designs can also be better simulated with using LTSpice or Multisim 35 3 3 3 Photo Diodes Photo Diode Sensor Analog front end incorporated with LED driver is paired with photo diodes The light wave goes through blood cells and received by photodiode sensor As discussed in section 3 2 2 specific wavelength must be used in order to obtain accurate measurement Low power consumption easy integration small form factor are the key requirement for Baby Peas monitor Advance Photonix Inc DPI E839 is a four drive emitter with three emitter diodes with wavelength 660nm 880nm and 940nm It has very small form factor of 6 73 mm x 6 73 mm x 1 90 mm It has maximum power consumption of 250 mW and peak forward current of 20
110. he entire read or write operation of data transfer The CPU would then be unable to perform other tasks while data is being transferred In this project data will constantly be updated and transferred from multiple sources The CPU would be unable to do basically anything but reading and writing data Other tasks would be put on low priority resulting in a tremendous slowdown of reaction time or other basic tasks If other tasks are put on high priority the overall time to execute is still much longer The CPU will need to allocate all its resources toward either data transfer or other computations Because the DMA header will be included the CPU will be able to delegate memory accesses to other components This will greatly increase the overall speed of the microprocessor and result in a better user experience Data Input Output A large amount of processing time will be spent managing data input and output The peripheral sensors will be constantly sending in new data to be manipulated The CPU will take care of many of the miscellaneous computing tasks that need attention while other components will be allowed to directly access the memory at any point A group of functions are needed to moderate the stream of input data into the internal memory Input data will be processed by the CPU and sent to the appropriate address in memory The software must be able to keep track of the locations of all the different memory within the RAM and flash memory An
111. he ninth data bit is taken from TB8 in SCON during transmit and stored in RB8 of SCON when received Timer settings are similar to mode 0 Figure 58 below illustrates the data transfer occurring in serial data mode 2 Note the extra bit The baud rate is determined by the equation 75MOD Fraud 64d Oscillator Frequency Receiver Samples Data in Center of Bit Time ase T ELEL LY teste BEE start Bit Data Bits 1 Stop Bit min Bit Time E t gt Figure 57 Serial Data Mode 2 Created by Xin Tong in MS Word 90 4 1 4 6 4 1 3 Serial Data Mode 3 Mode 3 is the same as mode 2 except the baud rate is determined the same way as mode 1 by using Timer 1 to generate communication frequencies 4 1 4 7 Microcontroller Coding Software The actions of the microcontroller hardware is controlled and regulated by its installed software For this project the CC2541 will be programmed in an integrated development environment capable of compiling high level languages The program code will be written in C C as opposed to assembly language This is due to the inherent complexity and relatively large amount of code needed to program the microcontroller directly with assembly code The data coming from each of the peripheral component will have to be organized manipulated and then sent out to the display In this case the display and user interface will be the smart phone application developed for the Android mobile operating system The peripheral sy
112. he onboard devices while maintaining the compact size The sensors and the peripherals were chosen with low power consumption as top priority The main focus for the product was user friendliness modularity and scalability The user interface was designed to be very user intuitive The hardware was simple and easily worn 11 The notable features on the KnightTime monitor e REM monitoring e Typical usage is for adults e Privately funded 3 1 3 Current Majority Market Share Monitors Various baby monitoring systems are currently available in the market They can be categorized by functionalities such as visual audio and movement monitoring system Most of the monitoring systems do not have any device implemented or attached to the babies thus they do not require FDA approval Motorola MBP36 Remote Wireless Video Baby Monitor uses video camera capable up to 590 feet with infrared night vision 5 It uses AC adapter as the main power source for the video audio device and sends the video to the parent unit which has rechargeable Ni MH battery pack This particular unit also features two way audio communication system with automatic channel selection The parent unit is a standalone 3 5 inch LCD display with speakers and microphone The retail price ranges from 150 to 250 based on additional features availability Philips AVENT Baby Monitor has a two way audio system with guaranteed uninterrupted connection 6 The packaging state that it
113. here the active edges or timing parameters become convoluted Understanding the timing of the SPI bus will be crucial for correctly programming the hardware such that communication runs smoothly 86 SCK MISO miri Figure 53 AC characteristics of the CC2541 Reprinted without alteration with permission by Texas Instruments 4 1 4 6 3 PC of CC2541 The CC2541 supports I C data communication with the TMP006 and MPU 6000 sensors contained within the Baby peas project The IC module is attached to compatible external device through a two wire IC serial bus The CC2541 will also use digital I O ports as chip select lines to activate each device The IC module features include e Compliance with the FC specification v2 1 published by Philips Semiconductor e 7 bit device addressing modes e General call e START RESTART STOP e Multi master transmitter receiver mode e Slave receiver transmitter mode e Standard mode up to 100kbps and fast mode up to 400 kbps support The I C module is accessed through pins 2 and 3 on the CC2541 Pins 2 and 3 can be reconfigured as general purpose I O pins if the module is not needed The IC data communication sets up a master device and slave device The master initiates the data transfer and also generates the clock signal Data is transferred through the serial data SDA pin and the serial clock SCL pin Both of these pins are bidirectional The rc module is enabled by setting the I2CCFG ENS1 bit
114. higher level A month and a half is given to integrate the software and hardware including all levels of testing and reworking Once this second hurdle is crossed all basic features will have been implemented In addition to the basic features the software schedule also have several stretch goals including two additional features of a utilities design and an editor and email functionality It is unlikely that both would be integrated but at least one software stretch goal is likely 7 2 Roles and Responsibilities The roles and responsibilities were divided up based on each individual in the group s goals and desires for learning different technologies to help in further career options While all members of the Baby Peas project will help develop and design each aspect of the project specific roles were assigned and accepted by each member to be the lead designer of their specific subsystem Christopher Ramirez e Hardware PCB design layout and schematic capture PCB assembly soldering and test Bluetooth RF section design Embedded Coding on the CC2541 Embedded Coding on the Atmega328p Power Supply Design Temperature Body Position Design Xin Tong e Android Development e Arduino Development Yowwu Lin e Pulse Oximetry Design e Hardware PCB design layout and schematic capture e Embedded coding for Atega328p Benjamin Goolsby e Embedded coding for CC2541 124 e Android Development 7 3 Budget and Finance Discussion The bu
115. his way 1f Newark does not stock the item it allows the designer to look elsewhere for a possible part solution 5 1 2 1 Digikey Digikey was founded in 1972 providing wide selections of electrical components It is now serving North America Europe and Asia Its headquarters is based in Thief River Falls Minnesota USA With 99 95 orders shipped on the same day it could be a very reliable source for Baby Peas project 107 5 1 2 2 Sparkfun and local hobby centers Sparkfun is an online retail store which offers parts for electronic projects Sparkfun also offers classes and online tutorials through its department of education a valuable resource for hobbyists and developers 5 1 2 3 Price list of Hardware BOM Development Tools Based on our research most suppliers have plenty of quantity in stock or offer alternatives Newark offers the lowest prices Some parts are available as free samples from the manufactures Parts needed for the fabrication of the PCB are listed Bill of materials Table 25 Not all components are listed which are needed for the PCB but the high level sensor parts which are the most expensive are listed Table 26 is a list of Development Kits the Baby Peas project will need for product realization TI AFE4490 18 657 Digikey Yes from TI Invensense MPU 60x0 series 1 10 72 Digikey N A 51295 MTE5066C UR 2 73 Digikey Fairchild QSB34CGR 0 84 TI CC2541 1 6 62 Digikey Yes from TI 5 75 Table 25 Intr
116. ical finger of user 3 Sensor movement and Attach peripheralto Verifies sensor can User displays ankle of users Attach still obtain an accurate heart rate medical facility Pulse accurate reading and oxygen levels Oximetry Sensor while sensor is still during slight equipment to index moving movements finger of user Table 35 Pulse Oximetry Final Test Matrix 6 3 4 Weight Battery Life and Wireless Range Final Test The weight test can be conducted in a lab environment using a calibrated scale The Battery life will be tested overnight at each group member s house The wireless range test will be conducted on UCF campus and in group member s houses Table 36 is the test matrix for the remaining system parameter test specifications Test Procedure Description Expected Result 1 Weight Test Place baby peas Verifies weight of Device weighs lt 11b peripheral sensor on device is less than lbs calibrated scale 2 Battery Life Power on baby peas verifies the sustained _ Device runs for gt 12 peripheral sensor and let operation of the device hours sensor run until battery for 12 hours dies or 12 hours is reached 3 Wireless Range Turn on the baby peas Verifies the wireless Device continues to Outdoors peripheral sensor and range specification is monitor all sensors and establish bluetooth met transmits the data to the connection to user display device at a range display device Android of 100 feet in 12
117. ime to time but should remain in a regular pattern regardless of the frequency Underlying disease may present if irregular patterns or waveforms are seen on EKG The maximum heart rate can be calculated by subtracting individual s age from 220 For example a healthy 35 year old male should have a maximum heart rate about 185 beats per minute Heart rate may change when illness are present As discussed in the body temperature section heart rate rises as body temperature increases for increased metabolism Medication can affect the heart rate as well Auscultation is performed by placing stethoscope on the chest and listening to the sound of the heart as it beats In one heartbeat a loud thump can be heard during systole and followed by a faint thump which indicates diastole In patient with congenital defects or dysfunction heart valves murmur is heard indicating the blood backflows A specialist should be consulted in these cases By employing a Baby peas unit the caretaker can see the normalized heart beat rate for the baby In a typical day a person s heart beat rate can change due to the biological circadian rhythm For a baby this is no different Having a Baby peas unit can help set a base line for the baby and alert the caretaker if a gross deviation happens 3 2 1 3 4 Breathing Rate Respiration is measured by a cycle of inspiration and exhalation The basic function 1s to exchange oxygen and carbon dioxide to maintain bodily functions
118. ing Resistive Touch Screens for Human machine Interface TI Data Acquisition 2005 n pag Web 1 Dec 2005 CR2450 Coin Cell Charger Web log post N p n d Web 01 Dec 2013 lt http chasingtrons com main 2012 3 26 cr2430 coin cell charger html gt Solar Charger Project Build A Solar Charger N p n d Web 01 Dec 2013 lt http www digikey com us en mkt solar charger html gt 360 NA Iq Step down Converter for Low Power Applciations N p n d Web 1 Dec 2013 lt http www ti com lit ds symlink tps62740 pdf gt 131 56 Bluetooth Android Developers N p n d Web 01 Dec 2013 http developer android com guide topics connectivity bluetooth html 57 Carpenter John and Karthik Kadirvel Electronic Component News Electronic Component News N p n d Web 02 Dec 2013 lt http www ecnmag com articles 201 1 04 practical lithium ion battery charger use solar panels gt 8 2 Appendix B Copyright Permissions 1 Nordic Semiconductors From Keeping Steven mailto Steven Keeping nordicsemi no Sent Tuesday November 26 2013 7 30 PM To cramirez36 cfl rr com Subject Re nRF51822 permission to use diagrams and figures from data sheet Hi Christopher Thanks for your interest in Nordic Semiconductor I checked with Nordic corporate in Oslo and you have permission to go ahead and use the layout diagrams Good luck with your project Kind Regards Steve From Christopher Ramirez l
119. ipher on a grainy screen Our product instead focuses on quantifiable bio markers such as pulse oximeter body position and non contact temperature sensors to indicate the baby s health This project strives to improve upon the current models and involves several factors for specific medical and social considerations Geared toward infants and young toddlers Baby Peas is designed to provide an empirical picture of the newborn s physical condition If the pulse ox detects sudden drops in pulse or oxygen levels a triggered alarm alerts the caretaker Whereas if relying on video observation the caretaker could find his attention distracted or misread a picture on the screen and lose critical minutes in a potential serious medical emergency In addition to basic pulse functions the body position and the temperature sensors can help monitor against risk factors for sudden infant death syndrome SIDS Although no definitive cause is known the medical community agrees on several factors that can magnify risk of SIDS The body position and temperature sensor should mitigate the risk factors The main goal is to attach a small device around the ankle of a baby and secure it in such a way it can read heart rate oxygen levels body position and skin temperature accurately without harm to the child Once the data is obtained the ankle device will transmit data wirelessly to a host device such as a smart phone At no time during the project will the ank
120. iption 3 3 1 2 Digital Pins Some of the digital pins are made for fault detection or reset Two of them are for connection to an external 8 MHz crystal For complete details please refer to AFE4490 user guide available on Texas Instruments website 32 3 3 1 3 Supply Pins The supply pins are mostly connected to the external power supply or to the common board ground Decoupling capacitors are required for certain pins They are not discussed in details 3 3 1 4 Communication Pins SCLK SPI clock pin SPISIMO SPI serial in master out SPISOMI SPI serial out master in SPISTE SPI serial interface enable Table 9 Communication Pins and Description The communication pins provide data transmission from AFE4490 to CC2541 via SPI protocol Please refer to hardware section 4 1 1 for details and block diagrams 3 3 1 5 Reference Pins The reference pins are connected to decoupling capacitors and the ground Pin 5 6 and 10 are open circuit pins and should not be connected to anything In conclusion AFE4490 provides complete solution to analog front end pulse oximeter sensor Not only it provides many fault detection but also many advanced features such as ambient light correction and precise timing controller SPI interface will work well with CC2541 for data transmission It could take extra time to configure the communication bus since the other sensors use C protocol Interrupt function will be written for incorporating the sensors co
121. is contained from address space 0000h to OFFFh Attempting to access addresses higher than OFFFh automatically seeks external program memory When programming the CC2541 the working registers located in the register bank will most likely be used to store data incoming from the peripheral systems through the Bluetooth wireless connections The general purpose RAM space will most likely be used to dynamically allocate memory through miscellaneous programming tasks The bit addressable memory will have an advantage of toggling and storing input or output bits that are necessary to track throughout the computing process 88 4 1 4 6 4 1 Serial Data Input Output The 8051 serial data communication circuit uses a number of special function registers SFR to oversee the transfer of data The rate of data transmission is known as the baud rate measured in bits per second The baud rate varies depending on the mode selected by the SFR register Serial data bits are first sent to the register SBUF to hold the data Register SCON controls data communication register PCON controls data rates and pins RXD P3 0 and TXD P3 1 connect to the serial data network SBUF is physical two registers both using address 99h One transmits data through TXD and the other reads data through the RXD pin Data transmission begins whenever data is written to the SBUF register Figure 56 is a representation of how the SCON Register looks Figure 55 SCON Register There a
122. is important and will be a factor in the choice of an accelerometer device Sensitivity of the device can be determined by the change in output voltage divided by the change in g The higher the g the more sensitive the device will be so the project needs to look for a device which has a high g Having an accelerometer device in the Baby peas project would be a possible solution for solving position Accelerometer semiconductor devices range in price size and accuracy The most important piece when choosing which device and the trade offs associated with it will be its power consumption related to accuracy and price Another aspect is whether we want a device which outputs a digital signal or analog signal If we choose an analog output then the microcontroller we choose will have to have its own built in analog to digital converter ADC circuitry If analog is chosen an external ADC may also be used but this drives up the cost and takes up more space on the circuit board If a digital output accelerometer device is used then the importance comes into play on whether it supports SPI FC or UART 38 3 2 4 2 Gyroscopes Gyroscopes unlike accelerometers measure the angular velocity around a specific axis Gyros have the unique ability to be unaffected by gravity whereas accelerometers are Gyroscopes are commonly used to give orientation of an object which is still in motion Gyroscopes like accelerometers are still references about an X Y and Z a
123. is low it shows a low voltage to the AND gate which in turn gives a low signal That bypass signal shows up on the switch in the upper right corner labeled BYPASS 62 In this mode the signal from VIN goes directly to VOUT The signal from VOUT is fed back to the error comparator through the error feedback network When the ON BYP pin is high the buck converter is active The STAT pin is the status pin used for monitoring the working mode of the TPS62730 When bypass mode is active the ON BYP pin is set to low The STAT pin should then also read as high impedance When the DC DC regulator is on the ON BYP pin is set high The STAT pin should read high as well in this setting This pin is modulated by the internal VIN comparator as seen in the functional block diagram Because STAT is simply an observation pin it 1s optional to connect this pin However most of its use can come in the development and testing process The status pin can be connected and monitored to ensure the components are working properly VIN Automatic ae Bypass hens Current Transition Limit Comparator Ve oF Va D E BYPASS A Gate Driver Min On Time Control Anti Logic Shoot Through Min OFF Time VOUT YY Integrated z Feed Back lt A Jere px ine 2 Comparato ero Negative Network gt Current Limit Comparator ON BYP ON BYP pi Figure 30 TPS62730 Functional Block Diagram Reprinted without alteration with permission from Texas
124. is stocked and ready for immediate shipment Table 10 below is a breakdown of the three devices along with their respective parameters side by side for comparison 2g 4g 8g 16g 2g 4g 82 28 de 8g Degrees Per Second 250 500 1000 2000 wa OO a E a Sandby Curent AA Data Oupus SMa PC O OO r C 800Hz bit mo oe SSS Bye Se Table 10 Comparison table of explored devices for body position sensor 40 From table 10 above it looks like the MPU 60x0 is the best bang for the buck It fits all categories except for power consumption The 3 9mA operating current still shouldn t affect the battery life of the entire sensor enough to cause concern Some of the deciding factors were the QFN package looks to be the easiest to solder down making installation of the device a bit easier and troubleshooting a little less of a worry The accuracy is much higher and this boosts the reliability of being able to provide the most accurate measurements of position for the consumer Careful scheduling must be adhered to since the device has a 2 3 weeks lead time In the end the MPU 6000 was very easy to implement and derived extremely accurate information The only problem with the device is it is very sensitive and provide 16 bit resolution so some of the slight changed in data can really show and cause the mapping for position to be difficult To better stabilize this feature on the microcontroller only the upper byte information
125. it 1s decided that Bluetooth would be the best fit for Baby Peas Light on power consumption this protocol is well used and well documented Additionally the new Bluetooth Low Power or Bluetooth Smart lowers the power even more 4 1 6 1 Android Platform for Classic Bluetooth Bluetooth network stack is already supported in the Android platform and native application programming interface API operations include other Bluetooth device scan query local Bluetooth adapter for paired Bluetooth devices RFCOMM channels service discovery data transference between devices and multiple connections Basically API is a set of functions with an unique task Android Bluetooth API can be broken into four categories of setting up the Bluetooth device itself searching for other Bluetooth devices in the vicinity connecting and data transference 56 103 4 1 6 1 1 Setting up the Bluetooth device Step one is to verify Bluetooth capability and switch on the Bluetooth The user can manually enable Bluetooth option under system menu but if the option is disabled the application can ask the user to enable the Bluetooth with the Bluetooth Adapter API Figure 69 Bluetooth permission request An application on your phone is requesting permission to turn on Bluetooth Do you want to do this Figure 68 Bluetooth Adapter API reprinted without alteration and with permission courtesy of Android The Bluetooth Adapter is the basic requirement f
126. l show up on the screen In this project the user interface is the Android GUI Input from the user via the smart phone will be sent to the processor as a priority task An interrupt may also come from the software An example of a software interrupt would be something like a new external input being detected that requires attention This could be a disc or USB drive In terms of this project a software interrupt could come from one of the sensors that are programmed to send an interrupt request if something out of the ordinary occurs If the child has a spike in temperature the software will trigger some form of alarm that will be executed before other activities Finally the processor can interrupt itself For instance if something goes wrong with the memory there should be a failsafe that recognizes the error and deals with it All three types of interrupts may occur during run time The coding should include functions that recognize all types of possible interrupt conditions and lists those tasks as priority execution The interrupt process also includes a number of memory access processes that must be handled during the interrupt process All software should handle interrupt requests and memory access in the order illustrated in Figure 60 Interrupt Process 94 Software Figure 59 Interrupt Process Flow UART SPIPC Data transmission is essential to the success of this project Data will flow from the peripheral units to the central pr
127. le device be tried on a child of any age range The concept can be proven out on members of the team and then scaled down in the future if so desired 2 2 Objectives Due to the nature of usage form and packaging comprises a large portion of design Because the unit is planned to operate under direct contact with the baby safety considerations include minimal invasion and heat dissipation In addition ergonomic concerns include ease of use bulk and portability Power factors in as well due to the targeted length of function time Primary objectives are wireless transmissions of the bio marker data to a hand held device which is reliable over a wide range of environmental conditions and for a specific length of time This objective goal needs to be reached by obtaining the bio marker from the ankle of the user By reaching these objectives all of the group members will obtain desired knowledge in their respective career interests which will eventually help out with employment options in the future 2 3 Project Requirements and Specifications The requirements and specifications of the project can been seen in Table 1 These specifications are baseline goals to be reached which can be measured against for the success of the Baby Peas project Heart Rate Accurcy 20 Skin Temperature Accuracy 20 Position Accuracy Back Stomach right side Left Side Wireless Transmission Range 100 Feet Table 1 Specification for the Baby Peas Project
128. lementation of the AFE4490 pulse oximetry circuitry and Debug capabilities It is important to understand how the SPI bus operates in order to successfully program the hardware The SPI bus also allows for scalability if more sensors are desired to be added to the Baby peas peripheral device The AC characteristics of the SPI bus are the timing cycles of the bus during data transmission The Serial Peripheral Interface bus specifies four logic signals e SCK Serial clock output from master e MOSI Master output slave input output from master e MISO Master input slave output output from slave e SSN slave select active low output from master Figure 51 below shows the direction of signals in the SPI connection from one master device to multiple independent slave devices The SPI Master sets the clock frequency to one that 1s at most the maximum frequency supported by the slave device During each cycle the master device sends a bit to the slave device which is read The slave device sends a bit to the master device and the master device reads the bit If these four actions occur the transmission 1s said to be full duplex because information 1s sent both ways MOSI MISO al Figure 50 Example of SPI interface Reprinted without alteration with permission from Texas Instruments 84 Once a SPI bus connection is confirmed on the hardware the master device and slave device can transmit data bits The master and slave
129. link can send data both ways A data link is synchronous when data is transferred on a clock cycle 3 2 6 3 UART A Universal Asynchronous Receiver Transmitter is a piece of computer hardware that translates data between parallel and serial forms This type of data transfer is considered universal because the data format and transmission speeds can be configured 3 2 7 Mobile Applications The project is going to be using a mobile application as the user interface A mobile application is a piece of software designed to do a useful function beyond the basic functions of making the computer run Multiple mobile services offer the ability to download and run applications on their mobile operating systems This includes the Apple App Store Google Play Windows Phone Store and BlackBerry App World 3 2 7 1 IOS The iOS is the operating system used for the products developed by Apple Inc such as the iPhone iPad and iPod Touch The 105 is based off the OS X kernel Software applications for the iPhone or related products can be downloaded on the Apple App Store The Integrated Development Environment for Apple products is called Xcode Xcode supports source code in C C Objective C Objective C Java Applescript Python and Ruby programming languages Xcode is one of the features on the 10S Software Development Kit which also include the 10S Simulator iOS Platform tools and Interface Builder The iOS user interface is programmed throu
130. low counter o 40 bit capture register to record start and end of transmission o Two 16 bit output compare registers and two 24 bit overflow compare registers to record start of RX TX or general interrupts Timer 3 and Timer 4 o 8 bit timers o Timer counter PWM functionality USART 0 and USART 1 o Can be used as either SPI master slave or UART o Provides double buffering AES encryption decryption o Uses AES algorithm with 128 bit keys o Supports ECB CBC CFB OFB CTR and CBC MAC ADC o 7 12 bit resolution from 30 kHz to 4 kHz respectively o Single ended or differential o Reference voltage can be internal AVDD or single ended differential external signal PC o Digital peripheral connection with two pins o Supports both master and slave operation Analog Comparator o Enables applications to wake up from Power Mode 2 or Power Mode 3 based on an analog signal 81 ON CHIP VOLTAGE Xx VDD 2 V 3 6 V RESET_N Q RESET lt WATCHDOG TIME h POWER ON RESET MOSC_ DKK ES cri BROWN OUT xosc o x CRYSTAL OSC T paa X 32 768 kHz p23 1X E CRYSTAL OSC P22 xE r 7 A mi BUG HIGH SPEED 32 kHz P21 Xx y INTERFACE RC OSC AS Pa0 xX P1_7 XE Pie P15 x P1_4 P1_3 XE P1_2 lt Pia lt 4 PO Xx POT Xx Pos Pos X Poa Poa gt lt Po_2 gt lt PO_1 gt lt Poop _ COMPARATOR AE ADG AUDIO D O CONTROLLER RECEIVE
131. m both the load current and quiescent current or standby current The portability of Baby peas faces a huge compromise if the quiescent current is large Figure 32 shows the different quiescent current with differing voltage in 64 1000 900 800 s b a 700 As 600 HHT 500 iit TTT LE TTT 400 _ aa TTT AAA 3 5 4 0 4 5 5 0 Input Voltage VIN V Figure 32 Quiescent Current During Differing VIN Reprinted without alteration with permission from Texas Instruments Quiescent Current Iq nA 100 0 2 0 2 5 9 The maximum operating current goes to 300 mA At 10uA the efficiency touches 90 In order to prevent ripple noise from propagating through the circuit TPS62740 also features low output ripple voltage and low noise with small output capacitor 55 The scheme behind this features is the dynamic operation of the no ripple mode operation In the past as the battery source start to get close to the output voltage on the regulator certain characteristics such as ripple voltage start to increase To stop this the TPS62740 uses a 100 mode operation at this point to lessen the impact of the ripple voltage basically the regulator changes to a linear like device and stops switching and the output is connected to the input voltage directly from the battery 55 Figure 33 demonstrates this principle The input and output form a y kx relationship at the l
132. mm QEN 40 package which can be soldered using a hot air pencil or standard solder reflow machine Below are the dimensions of the CC2541 0 50 a y J 4 EN a A i f 3 U a a i a F y y A nr THERMAL PAD SHOWN ON SHPARATE SHEET Figure 20 Dimensions of the CC2541 Reprinted without alteration with permission from Texas Instruments 48 Figure 20 shows the individual pins being 23mm While this is a QEN device the leads are exposed around the outer part of the device which enables the person soldering the device to be able to tell whether the device is properly soldered One thing the solder technician will not be able to tell is whether the devices thermal pad is soldered correctly TI data sheet on the CC2541 gives specific PCB layout recommendations Careful consideration of PCB layout will have to be utilized to make sure the device can be properly soldered in place Texas Instruments recommends working with a PCB fabrication facility before the final design 1s implemented and sent to fabrication 3 3 6 2 HC 06 Bluetooth Module The HC 06 is an all in one Bluetooth solution made for quick implementation and ease of use It is a PCB board which 34 pins but only 5 pins are needed for the design The Supply ground UART TX and UART RX It s a basic Bluetooth solution but is limited in interface abilities The unit can be bought mounted to a breadboard which makes bread boarding this device very simple and easy to get
133. mmunication AFE4490 is the most qualifying analog front end for Baby Peas Project but in the end the Baby Peas project ended up using a discrete design instead of the AFE4490 While the SPI bus was able to be configured and working there were over 40 register settings which needed to be configured in order to get the timing on the pulse oximeter working properly With time constraints being taken into consideration the problems associated with using the CC2541 the AFE4490 was dropped in the final design and a more easily implemented discrete design was used The discrete design did not include the oximeter portion and only provided heart rate data The detailed package dimensions are seen in Figure 10 The measurements are important for PCB layout Cadsoft Eagle is used for creating AFE4490 and the package dimension was taken into consideration 33 6 15 5 85 B Pin 1 Index Area 40 SX Top and Bottom NS F in co cn 0 80 0 20 Nomina Lead Frame 0 05 C 0 00 aox 900 THERMAL FAD SL AND SHAPE SHOWN ON SEPARATE SHEET Bottom View Figure 10 Package Dimension of Texas Instruments AFE4490 All the measurements are in mm Reprinted without alteration with permission by Texas Instruments 3 3 2 Alternative Design of Analog Front End Pulse Oximeter AFE4490 offers many features but not all necessary A Simplified analog front end can be designed with basic components and may reduce power consumption A design of a
134. mulations of this will entail placing the sensor on a table top in a stable position for 1 minute then moving it rapidly for 20 seconds then setting it down again in a different position and verifying the MOV icon under the body position data display portion is active during movement and inactive during no movement Table 34 is a the test matrix for the final acceptance testing of the body position sensor Test Procedure Description Expected Result 1 Stable up Postion Place peripheral device Verifies with the sensor a User interface display on a flat surface facing flat position the reletavive window displays up up and power sensor reading on the display __ position being read on should be up 2 Stable Left Right Place peripheral on one Verifies sensor updates User interface displays Side Position side first and then other position setting and gives new position of right side next alarm side or left side and gives audible alarm to the user 3 Stable down Place peripheral device Verifies sensor updates User interface displays Position on a flat surface facing position settling and gives new poistion of down alarm down and alerts the user audibly Place peripheral device Verifies sensor can During movement user on flat suface facing up display movement and _ display should indicate obtain stable reading _ recover with stable MOV and once Shake sensor for 20 readimgs sensor settles proper sec
135. n analog front end can be broken down into a few key components System diagram are shown in Figure 11 34 LED Drive LED DRIVE Supply D A Amplifier Low Pass Filter Instrumentation Operational Amp Analog to Digital Converter Figure 11 System Block Diagram for Analog Front End Discrete Design A digital to analog converter sends signal from microprocessor When it reaches amplifier the signals are boosted up in order for the driver unit to read the timing sequence for LED The LED with 660 nm and 940 nm should alternate each other between on and off When the photodiode sensor gets excited by the light goes through the object two currents are created based on different wavelength of light input The signals coming from photodiode sensor are relatively weak and unusable for typical analog to digital converter Some noise may need to be filtered out for accurate reading The amplifier portion can break down into three parts pre amplifier low pass filter and final stage of amplification Use the pre amplifier to boost up the currents from the photodiode sensor Filter can be a simple low pass filter or Butterworth filter for enhanced quality A final stage of amplifier boosts the currents to match the operational spectrum of analog to digital converter The currents are converted into voltage and transmitted to corresponding pin on the CC2541 microprocessor or any microprosessor Many ADC chips are equipped with I2C interface whic
136. n Human Body pere Perception level Slight tingling sensation Still dangerous under certain conditions Slight shock felt no painful but disturbing Average individual can let go However strong involuntary reactions to shocks in this range may lead to injuries to as the freezing current or let go range Extreme pain respiratory arrest severe muscular contractions Individual cannot let go and death is possible Ventricular fibrillation and muscular contraction and nerve damage beings to occur Death is likely Cardiac arrest and internal organ are damaged In addition victim will have severe burns Death is probable Table 4 Effects on human body due to different amounts of current 43 caretaker will have no knowledge of this other than the fact that the baby might cry more or display signs of discomfort that might be attributed to other factors such as hunger or the need for a diaper change In addition to shocks burns are another concern when dealing with power supply If there is not enough adequate heat dissipation the circuit can overload thermally and burn the wearer The degree of burn is usually a factor of both the thermal level of the object and how long the object 1s in contact with the skin Often times this kind of burn is insidious in nature due to the fact the person being burned does not realized that The thermal level of the object could be tolerable to the Skin but when taken into account duration can be
137. n Software Definition from PC Magazine Encyclopedia Application Software Definition from PC Magazine Encyclopedia N p n d Web 2 Nov 2013 PC Background Total Phase N p n d Web 24 Oct 2013 SPI Serial Peripheral Interface Mct net N p 1 Sept 2006 Web 30 Oct 2013 SPI Serial Peripheral Interface Mct net N p 1 Sept 2006 Web 30 Oct 2013 Oximetry Johns Hopkins Medicine N p n d Web 3 Nov 2013 Sudden Infant Death Syndrome SIDS KidsHealth N p n d Web 5 Nov 2013 SIDS Cdc gov Centers for Disease Control and Prevention 09 Aug 2013 Web 5 Nov 2013 Step Down Converter with Bypass Mode for Ultra Low Power Wireless Applications SLVSAC3C Texas Instruments 2011 CC2540 41 System on Chip Solution for 2 4 GHz Bluetooth low energy Applications User s Guide SWRUI91D Texas Instruments 2009 CC2541 2 4 GHz Bluetooth low energy and Proprietary System on Chip SWRSI00D Texas Instruments 2012 MSP430 FR59xx Mixed Signal Microcontroller SLAS704A Texas Instruments 2012 MSC1210 Precision Analog to Digital Conerter ADC with 8051 Microcontroller and Flash Memory SBAS203J Texas Instruments 2002 ATmega 8 bit AVR Microcontroller with 4 8 16 32K Bytes In System Programmable Flash 8761D Atmel 2009 129 29 30 31 32 33 34 35 36 37 38 39 40 41 PIC16 L F720 721 D
138. n csc support Americas html wfsegen DATE TIME UTC Thu 21 Nov 2013 14 17 21 GMT CUSTOMER S REGIONAL LOCAL TIME Thu 21 Nov 2013 09 17 21 AM EST Name Christopher Ramirez Prefix Mr First Name Christopher Last Name Ramirez Job Title student Company University of Central Florida Email cramirez36 O cfl rr com Phone 407 310 0830 FAX Country USA Address1 840 saint johns river dr Address2 City sanford State FL Postal Code 32773 Part or Description N A Category Technical Documentation Application Other Design Stage Prototype Estimated Annual Production n a units Production Date n a Problem I m an electrical engineering student currently at the university of central Florida We are currently building a vital signs baby monitor for our senior design project and we came across a pdf file with some explanations on accelerometers The pdf was created by TI and we were hoping to have permission to use some of the figures and graphs from the pdf in our senior design technical paper We ofcourse will not change the graphs or 135 figures in anyway and will properly cite TI s work The link to the pdf is http www2 usfirst org 2005comp Manuals Accelerl pdf 4 www AnaesthesiaU K com From adrienne frca co uk To wasiasd hotmail com Subject RE AnaesthesiaUK Web Site Feedback Date Tue 26 Nov 2013 08 45 29 0000 Dear Yowwu
139. n of SIDS being able to tell whether the baby is in the prone side or back position is vital to success Position of the baby can be monitored through a couple of different methods The Baby peas project could keep a camera on the baby being monitored This idea fits into the goal to achieve non evasiveness in the project but creates another external peripheral to integrate into the system Since the main peripheral to be implemented has other sensors attached to it a solution need to be found which can be integrated alongside the other vital signs sensors to keep costs and development time at a minimum Some technology solutions include the accelerometer or gyroscope 3 2 4 1 Accelerometers Accelerometers measure acceleration time rate of change of velocity of an object with respect to the Earth s gravitation While acceleration is not the object of concern for the Baby peas project one can derive position from acceleration data because the second derivative of position leads to solving for acceleration The following equation models acceleration as a function of position a t lt PO _ dO dt dt a acceleration v velocity x distance position t time d derivative notation Since we are measuring acceleration with the accelerometer we would need to use the mathematical method of integration to solve for the position Now how these devices actual measure the acceleration ranges from device to device Some devices use
140. n one mesh network e Simple protocol and faster time to market e Does not interfere with the crowded ISM band of 2 4GHz Cons e Low data rates e Only 1 source for z wave components and they only sell to OEMs and ODMs e Range might not meet specifications for project From an analysis of all the available wireless technologies the Bluetooth Low Energy technology seemed the best suited for the baby pea s project Due to low power consumption needed and a wealth of vendor support and example projects for both software and hardware implementation the Bluetooth Low Energy solution was thought to have fit best Unfortunately understanding the BLE software stack for the CC2541 was much more difficult than expected Problems with IAR embedded workbench design environment and the sample projects complexity level prevented the Baby Peas project with using the BLE design protocol In the end the BLE portion was dropped and Bluetooth Classic was used 3 2 6 Data Communications In computer architecture data is communicated between components using a bus Buses are also used to communicate between multiple computers Buses can be differentiated by the method of transmission differentiation of bits and authority to transmit The method of transmission can be either single ended or differential signaling Single ended signaling is the transmission of an electrical signal through a single wire The transmitted voltage is compared against a ground voltage to
141. necessarily the ambient temperature A separate chip is needed because the size of the sensor is a major factor to be considered in this project Many chips met the requirement but not all are necessarily appropriate Technologies involved with the sensor type include thermistor thermocouple resistance temperature detector RTD and semiconductor As seen in table 3 technology using semiconductor provides excellent accuracy and repeatability as well as low heat generation Temperature range Very wide Narrow Narrow typical values 200 C to 2000 C 20000 4 650 C 50 C to 300 C 50 C to 200 C Accuracy Medium High Medium High Repeatability Fair Excellent Fair to good Good to excellent Long term stability Poor to fair Good Poor Good Sensitivity out Low Medium Very high High Linearity Fair Good Poor Good Response Medium to fast Medium Medium to fast Medium to fast Size Packaging Small to large Medium to small Small to medium Small to medium Interchangeability Good Excellent Poor to fair Good Point end sensitivity Excellent Fair Good Good Lead effect High Medium Low Low Self heating No Very low to low High Very low to low Self powered simple Overall advantages inexpensive rugged vari Most trata cea ate High output fast two Most linear highest ety of physical forms wide orien wire ohms measurement output inexpensive range of temperature p ive slow current Non linear limited Non linear low voltag
142. ner diode The extra voltage that is not passed through is dissipated through the resistor that is part of the power regulation circuit Linear regulators are commonly used in hobby electronics and simple consumer electronic goods due to stability and cheap price point A familiar family include the LM78xx The primary disadvantage of the traditional linear regulators is the low efficiency Regulators such as the LM 78xx needs a high buffer zone between input voltage and output voltage For the LM78xx family the typically differential voltage is 2 volts That is an enormous cost considering that the entire circuit package needs to run around 3 6 volts and every volt added could mean bulkiness and weight in package In addition any extra voltage is dissipated as heat creating a thermal threat to the operation of the package and to the baby s skin The thermal and voltage differential can be solved by using a low dropout linear regulators Nowadays IC makers offer linear regulators with low differential with input output low noise and a fast transient response Some of options include such devices such as Linear Technology s LT1761 an option with a low dropout voltage of 300 mV at 100mA of 56 output current In a typical application the input output differential is a mere 0 4V This is a 500 improvement over the LM78xx family What is more the quiescent current for this unit is also very low at 20 uA The shutdown Quiescent current is less
143. nnected to a CC2540 similar to the CC2541 The figure shows how the two devices are probably connected in the CC2541 layout The power down signal is passed from the P1 2 MUX to the TPS62730 ON BYP input pin In this way the mode selection of the TPS62730 is dictated by the microcontroller programming If the ON BYP pin is low the TPS62730 is in its ultra low power bypass mode In this mode VIN is directly connected to VOUT through an internal Bypass switch and consumes only 30 nA typical input current The output of the buck converter is connected to the battery VIN When the pin is high the transition from Bypass mode to DC DC converter operation is enabled This transition state 1s to reduce the amount of ripple voltage to zero or near zero and is regulated by 60 output capacitors shown in figure and internal decoupling capacitors Once the capacitors are discharged sufficiently and internal comparators recognize the increase in input voltage the bypass switch is deactivated allowing normal operation of the DC DC step down converter TPS62730 L 22H Vess pap e 2 1V 3V c Cuur ym Cou sete T T 2 24F ON BYP STAT Power Down Signal P1 2 PMUX DVDD 1 DVDD 2 AVDD 6 AVDD 5 Vn 10000 100MHz 2 24F 14F 5x 100nF ed COO CC2540 power supply decoupling capacitors Figure 28 TPS CC2540 Reference Design Reprinted without alteration with permission from Texas Instruments 3 3 8 4 2 1 Pin Functions The pin descripti
144. nstration OSHA Construction ETool Electrical Incidents How Electrical Current Affects the Human Body N p n d Web 01 Dec 2013 Batzdorf Nick Supercapacitor Today s Energy Revolution Marketplace org N p n d Web 01 Dec 2013 The Hidden Schematic Lecture Web 1 Dec 2013 lt http 1eeeb okstate edu lecturenotes EET 4654 20Microwaves Lecture 2012 20 20 20The 20Hidden 20Schematic pdf gt Karki James Effect of Parasitic Capacitance in Op Amp Circuits Application Report 2005 n pag Web Human Comfort and Health Requirements N p n d Web lt http courses washington edu me333afe Comfort_Health pdf gt Electro Static Discharge ESD Briefing At READE Electro Static Discharge ESD Briefing At READE N p n d Web 01 Dec 2013 lt http www reade com Safety esd html gt Williams Andrew Touchscreen Lowdown Capacitive vs Resistive The Full Signal N p n d Web 01 Dec 2013 lt http www thefullsignal com products 7831 touchscreen lowdown capacitive vs resistive gt Resistive vs Capacitive Touchscreen Tech Explainer Tech Explainer N p n d Web 01 Dec 2013 lt http techexplainer wordpress com 2012 04 02 resistive vs capacitive touchscreen gt Raspberry Pi Display Module 3 2 Touchscreen LCD LCD 11743 Raspberry Pi Display Module N p n d Web 01 Dec 2013 lt https www sparkfun com products l 1743 gclid CJ6Gq8q3gLsCFSho7AodO WIASO gt Downs Rick Us
145. nt focuses similar functionalities particularly the video monitor portion The monitoring system is augmented by user input functionality such as two way audio This is achieved through a wireless component such as WIFI or Bluetooth The cost varies from 10 USD to upwards of 150 USD What the current market share lacks is a focusing on empirical data collection All of the data collected are usually by visual inspection only and there is no algorithmic manipulation of bio marker data 3 2 Relevant Technologies 3 2 1 Medical Most parents have found infants have totally different sleep cycles then they do waking up in the middle of the night to take care of screaming babies becomes a daily routine The newborn spends about 16 hours a day sleeping on average which is about twice as much compared to adults As the babies get older their sleep cycle will start to have a regular pattern To accommodate the way babies sleep an understanding of their sleep stages is critical Just like adults infants have REM rapid eye movement and NREM non rapid eye movement Dreams occur during the REM stage of sleep which are often referred to as the active stage of sleep During the first couple months of life newborns have about 50 of REM stage As babies get older the REM stage will become short and by the age of six months REM state will be about 30 of sleep NREM is the quiet stage of sleep where hormones promote growth and tissue generation Studi
146. nverter which is acceptable for the project design The resolution of the ADC converters is 12 bits The biggest advantage to the FRAM series is the low power consumption to data throughput ratio Data writes occur at 125 nanoseconds per word In active mode the typical power consumption is 103 uA MHz In Standby mode the consumption is 0 4 uA Shutdown mode typically uses 0 02 WA 26 Advantages of the MSP430 FRAM e Very low power consumption e 14channel Analog to Digital converters e High data throughput ratio e Fast memory write time 52 3 3 7 2 ATMEL The Atmel model ATmega328P is a high performance low power 8 Bit microcontroller It features a RISC architecture with 32x8 general purpose registers and 23 programmable Input Output pins Data throughput is listed at 20MIPS at 20 MHz It contains 32KB of programmable flash memory IKB EEPROM and 2KB SRAM The ATmega328P supports Serial USART Master Slave SPI Serial Interface and is compatible with I2C data transmission Operating voltage ranges from 1 8 5 5V and has a speed of 0 20 MHz Active Mode consumes 0 2 mA Power down Mode at 0 1 uA and Power save Mode consumes 0 75 uA 28 Advatanges of the ATmega328P e Multiple data communication options e Low power usage and Power save Mode e Good amount of input output pins e RISC architecture 3 3 7 3 PIC MICRO The Microchip Pic model PIC16F720 is a high performance microcontroller with RISC CPU architecture Operating speed occur
147. o Plot Reprinted without alteration with permission by Texas Instruments The accuracy of the pulse oximeter level can be affected by room ambient light the position it is attached to be body part the coverage between light source and receiver Cool and clammy skin caused by poor peripheral perfusion could prevent reading from the sensor Care must be taken to package the sensor in a light tight enclosure to shut out possible noise 3 2 3 Temperature Sensors General parameters in this application for temperature sensors are low power consumption easy to integrate and small form factor Proper power management is essential for safe operational environment The sensor will be used to measure skin temperature on the infant In Baby Peas project a thermopile sensor will be used due to its capability of measuring temperature without skin contact With high power 13 consumption the element may be heated and cause discomfort Fire hazard is another issue since cloth may be used to conceal the element With numerous temperature chips available on the market our goal is to acquire one that can be easily used with our microprocessor Many microprocessors are under consideration but CC2541 from Texas Instrument meets all the requirements Sensors that are compatible with CC2541 are the top candidates in this application Some models of microprocessors are equipped with internal temperature however they are read the temperature of the chip and not
148. ocessing unit through the SPI and FC channels A number of functions must be programmed to first initialize the SPI and IC and then set the destination for all data coming in from each component This section includes the memory access and input output function previously described 4 1 4 8 Debugging Feature CC2541 The debug interface is used during the development phase to manipulate the processor if any problems arise It is almost guaranteed that there will be some part of the initial versions of the microprocessor programming that does not work the way it is intended to The debugging system can be used to step through the run time task executions on the 95 microprocessor to identify the problems This is invaluable if a part of the program does not work in the way it is supposed to The debug interface uses a SPI like two wire interface using the pin P2 1 for debug data and P2 2 for the debug clock Table 23 shows the basic AC characteristics of the debug interface Te O CT OTTE E e 178 E E EXT_RESET_N low to first ice meet edge on debug clock ty ty Debugdataseup data setup ts EXT_RESET_N high to o debug command te Debug data setup ty Debug data hold i tg Clock to data delay Load 10 pF Table 23 AC Characteristics of the debug interface Figure 61 below illustrates the timing characteristics of the debug clock when the RESET_N pin is pulled low Initially there is a short delay between the reset and the first falling
149. oductory BOM for the Peripheral sensor PCB SK 24PTU PI CC2541 SensorTag Development Kit Pod Y IT Yes from TI Table 26 Software Development Kit BOM 108 5 2 PCB Vendor and Assembly Printed Circuit Board Vendors provide services which take something called gerber files which are generated from a type of CAD software tool like CAD EagleSoft and are able to generate a fabricated Printed Circuit Board without any components soldered to the board Printed Circuit Board assembly houses provide services which place each component on the circuit board and then solder them They use pick and place machines which automatically place each part in the right location and position on the PCB and then run the board through an oven at a specified temperature per part which enables the part to be properly soldered down They then run the board through a machine which automatically provides visual inspection of the solder connections They have certified inspectors which provide visual inspection of the boards as well 5 2 1 PCB Vendors Printed Circuit Board PCB fabrication has a wide selection of possibilities to choose from Due to time constraints a vendor which offers low pricing and quick turnaround time will be used for the PCB fabrication of the peripheral device PCB 5 2 1 1 4PCB 4PCB is an online manufacturing provider of Printed Circuit Boards They provide 2 layer boards student pricing covering 60 square inches of circuit board s
150. of electrical signals If a biasing resistor was not connected to this position the voltage applied to the internal components may not be constant resulting in unintended outputs The R301 resistor is a precision resistor 1 at 56 KQ Pins RF_P Pin 25 and RF_N Pin 26 connect the CC2541 internal components to the electrical signals provided by the RF network and the Bluetooth modules RF_ P deals with the positive component of the radio signal either being received or broadcasted RF_N deals with the negative component of the radio signal being received or broadcasted These 83 two pins are extremely important to layout correctly to adhere to impedance matching characteristics which arise in mircrowave circuits P2_3 XOSC32K Q2 Pin 33 and P2_4 X05C32K_Q1 Pin 34 pins are attached to an external 32 768 kHz oscillator This oscillator is used as a clock for the input output pins and receives information from the high level clock MUX and calibration circuits DCOUPL Pin 40 A capacitor is attached from this pin to ground It acts as a decoupling capacitor for the CC2541 A decoupling capacitor is used to filter low frequency noise out of the circuitry Without a capacitor at this pin the internal components of the microcontroller would see more noise potentially causing a slowdown of processing speed or incorrect information being passed through the system 25 4 1 4 6 2 SPI bus AC Characteristics of CC2541 A SPI bus will be needed for the imp
151. om Sensors Via SPI or rC CC2541 RF Output Impedance Debug Header matching ae ae network Programming Troubleshooting 32MHz 32 768 kHz Oscillator Oscillator Figure 46 Block Diagram for CC2541 From Figure 48 one can observe the CC2541 is the heart of the system because it handles both the RF and Microcontroller aspects of the baby peas design Figure 48 is the schematic design for the CC2541 and will be discussed in the following sections for both the RF and Microcontroller aspects of the project 76 1 CC2541 or MicroStrip Antenna MURATA BALUN E 41K X1 OSC 32 768 KHz Vv AE OSC 32MHz _ C11_ C _ oT Y i i Lof Figure 47 Schematic design for the CC2541 Communications Microcontroller Created in Cadsoft Eagle by Christopher Ramirez From Figure 48 we see that most of the capacitors connected in parallel have to do with low and high frequency noise filtering This is a critical portion of the project since a switching regulator is used RF devices need clean power to be able to transmit data bits efficiently Noise on the device can effect receiver sensitivity and cause degradation of the system The impedance matching network was chosen to be a murata balun which was suggested for ease of implementation to guarantee proper impedance matching to 50 ohm so the transmit and
152. onds then set back position reading should down be displayed within 5 sec Table 34 Body Position Final Acceptance Test matrix 6 3 3 Pulse Oximetry Final Test The pulse oximetry test 1s the heart and soul of the baby peas project It provides heart rate and blood oxygen levels which are critical to the data needed to see if the body is starting to dive into a fatal state Pulse oximetry testing will be conducted at a medical facility which a group member is employed at The facility has graciously allowed the baby peas project the use of a pulse oximetry sensor to compare our sensor readings Table 35 is the test matrix for the pulse oximetry sensor The sensor will be attached to each member of the Baby pea s project for validation over a different range of users 118 Test Procedure Description Expected Result 1 Heart Rate Accuracy Attach peripheralto Verifies the Pulse User displays heart ankle of users Attach Oximetry sensor and rate information and medical facility Pulse obtain accurate heart accuracy is within Oximetry Sensor rate information 20 of the medical equipment to index finger of user 2 Blood Oxygen Attach peripheral to Verifies the Pulse User display shows Accuracy Test stable ankle of users Attach Oximetry sensor can blood oxygen medical facility Pulse obtain accurate information and Oximetry Sensor blood oxygen levels accuracy is within equipment to index froma user 20 of the med
153. one to configure the Bluetooth pairing In those menus one will find the HC 06 is broadcasting and must pair with that device Once paired the Baby Peas application can be opened 125 good ms 1 000 cd y he K Ta Figure 72 BabyPeas battery Jumper and Pulse LED Locations On the Baby Peas Application click on the Monitor button to open the monitoring section of the application Once in the Monitoring section is open you must hit the connect button and choose the HC 06 available for connecting too Below in Figure 74 is a display of the Menu Screens Y Y Screen1 Monitor Reset ME Reset Object Temperature F Connect i Rotate LG QuickMemo Figure 73 Menu Screens 126 Once connecting to the BabyPeas device once should start to see data displayed for the pulse object temperature and position The data is updated throughout using the Baby peas product To obtain the pulse place your finger on the opposite side of the board over the portion of the board where the green LED is showing through Your finger must be free of moisture and must remain still for the pulse to be detected Once detected the pulse portion of the monitor should start updating and show accurate pulse readings To obtain object temperature one must hold the baby peas circuit board over a portion of the skin but not touching and observe changes in the Skin Temperature under the object temperature portion of the monitor To ch
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155. ons contained in Table 17 for the TPS62730 are helpful references to understanding exactly how the chip will be connected to the CC2541 The functional block diagram is also more easily understood knowing the pin functions Figure 29 below depict on the next page shows the efficiency versus Input Voltage left and Output Current right of the TPS62730 in ON mode ON BYP high The trends for the efficiency of the chip versus output current shows positive correlation between output current and total efficiency for various input voltages Although there is an expected dip in efficiency for larger input voltages all voltages in the operating range are above 85 percent even towards larger output current values The orange graph line shows the chip operating in bypass mode In bypass mode the efficiency peaks at almost 100 percent from 1 10 mA This makes sense because in bypass mode the voltage 1s going straight from VIN to VOUT through the bypass switch The right figure shows the efficiency with respect to input voltage The efficiency once again increases for larger values of output current However there is a slight negative correlation as the input voltage increases The efficiency still manages to stay about 80 percent from ImA to 100mA At high input voltages the 100mA ends up being the most efficient 61 Heme mo YO Certo PWR Power supply pin Ground supply pin Mode Selection pin Pulling pin low forces device into ultralow power
156. or any Bluetooth activity In the code the device is first asked to search for the device s Bluetooth adapter by the getDefaultAdapter call If the call returns null then the adapter does not exist and no Bluetooth connection can be made If an adapter exists the code can use isEnabled to look at the status of the adapter If the user has manually enabled the Bluetooth module then the result would indicate false If the user has not manually enabled the Bluetooth module then the code can enable the Bluetooth by startActivityForResult function call and ACTION_REQUEST_ENABLE Intent This displays Figure 70 screen to the user When the user clicks yes then the Bluetooth device is enabled and can start searching for other devices in the vicinity 56 4 1 6 1 2 Searching for other devices The two options for this portion is device discovery or looking for list of paired devices Either method should work for Baby Peas For device discover a general call is made out to any discoverable devices in range and once an object is discovered a connection is made by exchanging identifying information For list of paired devices identifying information is already stored on the home Bluetooth device and the benefit of that is the connection can be made whenever the range is optimal Due to the time saving nature of 104 paired devices it is probably the best method for Baby Peas To have a unique monitor for each baby furthers the cause of indivi
157. or hot air pencil The great part about this device is the leads can be seen from the outside of the component and solder can wick up the sides of the leads thus letting the user know a proper solder connection has been made The baby peas project group has an experienced J STD 001 certified specialist in soldering of surface mount components so QEN packages should not be a problem 3 3 4 2 Analog Device ADXL362 The ADXL362 accelerometer made by Analog Devices is an ultralow power digital output MEMS system on chip During a 400Hz data rate output the device is only drawing 3 0uA with a supply voltage of 2 0v This is extremely beneficial for the baby peas project due to the desired lower power consumption on the peripheral device It has 12 bit ADC output resolution and communicates using a SPI interface to the microcontroller Another feature is the device can be programmable to only output 8 bit resolution if lower resolution is possible This may prove to be handy if the project notices accurate readings can be taken utilizing less bit resolution giving it less power consumption and easier byte transfers It is a 3 axis accelerometer and has selectable range measurements of 2g 4g 8g with a resolution of Img LSB on the 2g range Like the MPU 60x0 series the ADXL362 has an onboard FIFO which enables burst data transfers which allows the system processor to go into a sleep mode while the ADXL362 is sampling the signal The device also ha
158. orts and flexibility In addition a USB charger from a PC or a USB wall converter would both work The three choices are to make a USB charger integrate a USB charging port on the baby peas unit or buy a USB charger In the interest of the time constraints due to the fact that manufacturing a baby peas unit with a female micro USB charging point would require some modifications to the schematic already designed it is recommended to have this as a stretch goal If the main features on the unit are functioning within required constraints i e the sensors and communications protocol then it 1s possible to consider integrating a recharging circuit to the existing circuit using a linear charge controller unit such as MCP73832 This is a decision to be made early on during prototyping section of the project If it is not possible to integrate a power recharge circuit many stores also offer PCB breakout boards A private vendor sells a board built around the MCP79832 for around 5 dollars 53 It would be simple to populate and have a viable working unit Finally a pre built USB charger is surprisingly absent from the market During a cursory search of the available resources there are no suitable units for sell 55 3 3 8 3 2 Solar For solar supply the same applies as the USB charger This feature is considered a stretch goal As discussed in section 3 2 9 3 a simple schematic is drawn for a solar USB charger kit sold by Digikey It outputs to a
159. other set of functions will then access the memory when needed to output data to the UART The memory must also have a number of safeguards to ensure memory does not get unintentionally erased due to lack of space or bad allocation determination A series of program tests will elucidate the effectiveness of the programming Figure 59 below is a representation of the data flow inside the CC2541 Bluetooth Figure 58 Data flow inside CC2541 Interrupts The processor needs to have a hierarchy of tasks to execute throughout the run time of the system The software will have a section of code that checks the state of the system and assigns priority when needed When a high priority task reveals itself the software should recognize the urgency of the task and put it at the top of the tasks to be executed All other tasks will be momentarily suspended and the previous state will be saved in memory Once the high priority task is complete the previous state will be obtained 93 from memory and regular processes will resume Based on this description the flow of command will come from an interrupt source to halt operation An interrupt can originate from the hardware the software or the processor itself An example of a hardware interrupt would be some sort of user input on a traditional computer For instance if a key on the keyboard is struck the priority task is to execute the task indicated by the keystroke If a letter is typed the letter wil
160. ow each individual sub system will interact with each other The Battery Re charge section will serve as both as a re charge circuit for the battery and also a protection circuit for the system not allowing the system to be in operation during re charge mode The Re chargeable battery will be a simple Coin Cell re chargeable battery feeding into the DC DC voltage Regulator circuit The Voltage regulator circuit will provide isolation to the rest of the circuit along with power to each sensor and the RF Microcontroller module Each sensor will interact with the infant in some way and transmit data over either SPI or IC to the CC2541 The CC2541 will process the data received and transmit data packets to the user display device The following sections will dive deeper into the hardware design of each subsystem providing schematics for each section with a final schematic of the overall system 70 Figure 39 Baby Peas System Hardware Block Diagram 4 1 1 Pulse Oximeter Sensor Design AFE4490 was the analog front end chip that was used in Baby Peas as the first choice The detailed description can be found in 3 2 2 In the schematics all the decoupling capacitors were added The SPI interface is pin 24 to pin 27 in the following order SCLK SPISOMI SPISIMO and SPISTE The corresponding digital I O for SPI interface on CC2541 is PO_5 PO_2 PO_3 and PO 4 71 GND GND GND eS Te GND GND 0 1uF le e nr 8 MH 4 U1 C2 MHZ fl 0 1uF 0 1uF CC254
161. ower voltages while at higher voltages the out is a constant The x value is the input value and the output voltage is the output value while the k value represents a constant multiplier At the lower voltages this just means that what comes into the regulator is output on the other side at an almost 100 mode At higher voltages the regulator starts to function like a traditional switching regulator and regulate the incoming voltage down to the correct output voltage 65 2 50 lour 10mA rising Vn lour 10mA falling Vn lour SOMA rising Vn l l 2 45 2 40 our DOMA falling Vin our 100mA rising Vn 2 35 our 100mA falling Vy 2 30 2 25 f 2 20 Output Voltage Vour V 2 15 2 10 2 05 Var 2 1V L 2 2uH LPS3314 2 00 2 20 2 25 2 30 2 39 2 40 2 45 2 50 Input Voltage V V Figure 33 100 Mode Transition for Vout of 2 1V Reprinted without alteration with permission from Texas Instruments Intended to run from rechargeable Li Ion batteries this unit can have an input range of Vin from 2 2 V to 5 5 V The additional nicety about this unit is the different levels of voltage output Ranging from 1 8V to 3 3V four voltage select pins can be pulled high in different configurations in order to output differing voltages in 100mA steps Table 18 shows the different voltage selections levels and pin configuration logic for the Baby Peas project This feature is great due
162. p and light portable microcontroller It is recommended to develop touch screens as plan b for 1t introduces more unknowns into the project and raises development costs by quite a bit A 3 2 screen from 4D sells for 84 95 on the well known hobby site Sparkfun 5 1 4 1 5 2 Software Development Writing and optimizing code forms a significant portion of this project An earlier section went over the three major market share platforms for development Android Windows and 1OS The choice between the three involved several levels of calculations availability of open source entry to market cost east of development and market share As a student project gleaning information from other sources constitute a significant portion of the journey An open source platform usually contains a larger and more active developer user base In this case of the three platforms Android is known for being open source and having large samples of code available for learning While Windows has the backing of Microsoft and large amounts of documentation its market share is simply too low compared to Android or 10S to seriously consider having the Windows platform as the ground unit The entry to market is also another serious consideration due to the novice nature of the group s experience in mobile development In addition the group also has limited funds and the mobile portion is just a part of the whole project After looking at the different price points of
163. pace for 33 00 dollars or a 4 layer board covering 30 square inches of circuit board space for 66 00 dollars They have a turnaround time of 5 days and also provide free Design for manufacturing tests which means they look at the PCB layout provided and check to make sure tolerances between trace widths and such are within the standards for PCB fabrication 5 2 1 2 PCB Fabexpress PCB Fabexpress 1s another online PCB vendor which provides quick turnaround times of 5 days but have some minimum order requirements which drive up the price Any 2 layer bare bones PCB no silk screen or solder mask has a standard cost of 40 00 with 60 added for every square inch While customization for size and cost is a great option the minimum order quantity could get expensive 1f a redesign effort needs to be done during the project testing and evaluation period 5 2 1 3 Custom Circuit Boards Custom Circuit Boards provides PCB fabrication with extremely fast turnaround time of 24 hours 1f needed They do not have a standard 2 or 4 layer pricing matrix but quote each PCB separately When the PCB design 1s completed for the Baby Peas project the gerber files will be submitted for quote to obtain pricing From the evaluation of these three companies it is decided the Baby Peas PCB fabrication will be done by 4 PCB The pricing and space could not be matched along with the added feature of the design for manufacturability allows an expert pair of eyes to evalua
164. perating per Test Matrix _ proper operation Function for enabling MPU Compile MPU 6000 Verifies the enable and No errors in compiled Table X interactions and verify soft start of the AFE4490 code AFE4490 AFE4490 is operating per voltage regulator for operating correctly 5 Function for enabling AFE4490 Compile AFE4490 function Verifies the enable and No errors in compiled Test Matrix Table X proper operation Function for enabling wireless Compile CC2541 wireless _ Verifies the proper setup No errors in compiled communications portion of the communications settings of the wireless code Bluetooth CC2541 communications settings operating correctly Table 31 Test Matrix for Software functions of the CC2541 microcontroller 6 2 2 User Interface Module Software Test The user interface hardware to be used for the baby peas project will be either a Samsung Galaxy S3 4 phone or some other Bluetooth low energy compatible device with a display The main reason to test an applications user interactive software is this is what the customer sees all of the time If this portion of the device is not quick easy robust 115 and intuitive then the user will have no desire to use the device regardless of how good the hardware accuracy is The Software will be tested by loading the designed application on the smart device and walking through each feature and validating features load quickly and display in a way which provides all the necess
165. posed to air is very volatile and can be explosive The unfortunate thing about super capacitors is size at this time With current state of technology a super capacitor 1s power dense able to discharge and consequently recharge rapidly but it is not energy dense for the comparable size of a batter package it holds much less charge In order to have sufficient power for the unit size would have to be sacrificed For traditional chemical batteries the button battery would be the best package for the baby peas unit It is the lightest in terms of weight one of the longest continuous usage options and is often used in medical applications While danger does exist in the chemical nature of the battery the packaging is safe enough for usage that these batteries are often used in the hospital setting or with every day consumer goods 44 25 3 2 9 1 3 Interference Considerations In addition to being a reliable power source for the electronics and peace of mind the power subsystem also needs to consider causing interference with other subsystems In general the different components of a circuit are taught as idealized versions with no interference among the different components However in practice parasitic inductance and capacitance are serious issues that can impact usage hours and quality of usage According to source x any two conductors will have a capacitance between them any conductor used for carrying current will have inductan
166. ppropriate part for the wireless sensor the performance and power consumption are the primary specifications to consider This is because the microcontroller with be mounted on a peripheral unit and act as part of a wireless transmitter The MCU should use a minimal amount of power to maximize battery life while being able to achieve the necessary performance standard needed for its actions The data processing required will have to do mostly with interpreting analog data coming off of multiple sensors measuring vital signs and position The microcontroller will communicate with the four sensors through a data bus The microcontroller will also interface with a Bluetooth wireless system and thus must have some form of serial or parallel data communication on it 3 3 7 1 TI MSP430 FRAM Series The MSP 430 FR59xx model has a 16 Bit RISC architecture It offers a low power option with a high speed It has a max speed of 24 MHz The FRAM series contains up to 64 KB of Non volatile memory and 2 KB of static RAM There are 17 40 general input output pins It is compatible with UART I2C and SPI data communication The controller features enhanced serial communication options This supports eUSCI_AO and eUSCI_A1 having a UART with automatic baud rate detection IrDA Encode and Decode and SPI with rates up to 10 Mbps The eUSCI_BO supports FC with multiple slaving addresses and SPI rates up to 8 Mbps This series also contains a 14 channel Analog to Digital co
167. prototyping and can be included in the final product if the mobile phone or tablet does not provide the best user experience There are several options for touch screens 4 1 5 1 Touchscreen In today s world a common user interface for everyday consumer smart phone applications is a touch screen due to its innately intuitive nature The tangibility of a touch screen creates a closer experience for the user and allows the developer to create applications that may be complex in the backend but have clear and concise availability on the front end facing the consumer This suits Baby Peas particularly well due to the strong date driven character of the unit All information gathered 1s quantifiable to both general statistics and to the individual s historical statistics To have a user shift through all that can create confusion Having a touch screen simplifies the process leaving the caretaker free to make higher level decisions As mentioned above one route for design is the mobile phone the second route is an LCD touch screen attached to a base station and the third route is a personal computer screen The next section goes over the finer points of the two types of touch screens and why resistive was selected 4 1 5 1 1 Resistive Touch Resistive touch screens comprise of electrically conductive and resistive layers on a glass panel Sometimes acrylic panels are also used Figure 65 shows a generalized picture of the glass material and two l
168. provides crystal clear audio signal to the paired unit with automatic channel selection Both the baby and the parent devices have a rechargeable battery pack with a low battery warning light The claimed operation duration is twenty four hours of usage and eight hours of battery recharging time This baby monitor uses DECT digital enhanced cordless communications frequency band 1920 1930 MHz in the US and Canada for encryption and clarity purpose The streamed audio signals are encrypted with 64 bit encryption LED lights on the parent unit are the indicators for baby environment sound level even when the units are muted Similar products with comparable features are ranged between 25 dollars to 120 dollars Baby movement monitors either utilize sensor enclosed pad or wearable 4 device on the body Angelcare Movement Monitor has sensor pad which is placed under the mattress to detect the body movements of the baby If no movement is detected for 20 seconds the LED light and a sound alarm will go off Snuza Halo Baby Movement Monitor uses flexible belt with onboard sensor attached to the abdomen of the baby It sends out alert signals if the baby does not move for 20 seconds or has less than 8 movements per minutes It is advertised to be small portable and easy to use Before sending alert to the parents Snuza baby monitor will vibrate gently when no movement is detected for 15 seconds 10 In summation the baby monitors in the existing docume
169. re four possible modes depicted in Table 22 for the SCON O Shift register baud f 12 9 bit UART baud f 32 or f 64 9 bit UART baud variable o jo o fji P Table 22 Possible modes of the SCON Register The TI bit is set high whenever data is transmitted and the SBUF register is clear to be written to The receive enable bit REN must be set to 1 for data to be received Once data is received receiver interrupt flag RI must be set to 0 to obtain new data after the previous data has been interpreted and dealt with Reception of data can start in modes 1 2 and 3 if RI is 0 RI must be reset by the program before the last bit of data is received or the incoming data will not be transferred to the SBUF register Serial Data Mode 0 Shift Register Mode Pin RXD is used to receive or transmit eight data bits The TXD is connected to the internal shift frequency pulse source The shift frequency in this mode is 1 12 the oscillator frequency The 8051 is the CPU core of the CC2541 and will thus act as the master device This gives it the authority to set the serial clock and baud rate 4 1 4 6 4 1 1 Serial Data Mode I Standard UART SBUF is a 10 bit full duplex receiver transmitter that can receive and transmit data simultaneously Pin RXD receives data and pin TXD transmits The transmitted data begins with a start bit followed by eight data bits and finally a stop bit After the stop bit the interrupt transmission fl
170. receive power levels are accurate with the ones provided on the data sheet Discrete inductors and capacitors can be used also if the murata balun proves to be difficult to install The antenna used will be constructed within the microstrip line itself Design details for the microstrip line are provided by Texas Instruments The remaining items on the schematic are talked about extensively in the following sections 4 1 4 2 Microcontroller CC2541 Design characteristics The CC2541 was determined to be the microcontroller with the specifications which is best suited for the Baby Peas peripheral sensor system The advantages to using this particular model include the Bluetooth module on the same chip large amount of memory and high efficiency through the flexible power modes The microcontroller itself supports enough flash memory and is fast enough to successfully handle the processes that are required of it The number of input output ports is also a sufficient number and resolution to support the sensors to be used The development kit comes T1 with examples of how to program biomedical devices which will be a valuable resource during the building phase 4 1 4 2 1 Electrical Characteristics The typical current consumption of the cc2541 in different settings are as follows In standard and RX mode with no peripherals active and low MCU activity the current consumption is typically 17 9 mA If the standard mode is switched to high gain mode ke
171. rformance under varying sunlight A charging unit has to sense the available current from the solar cells If the circuitry tries to pull the same amount of current under changing conditions then the voltage can collapse and the charging action is stopped This undermines efficiency Reverse leakage protection This actually is an issue when there is a storage element in the circuitry The stored element can leak charge back to the source if the stored element in the case the battery has a higher potential than the source _ X1 7 ON D1 5 IC2 Y MBR750 1 786TV aM n Y 1 3 31 Y O VI VO al gt i GND NI NI L ND ND L ND GND GND Figure 8 Schematic for phone charger Created by Xin Tong using Cadsoft Eagle 30 Figure 8 gives the circuit of a general solar to USB phone charger 54 The solar cell used here is the 750 00032 manufactured by Parallax and costs 59 99 per unit The specifications for this cell are 10W power 18V at Pmpp and 580 mA at Pmpp While this unit is very powerful a better price point could be found with less powerful solar cell that would use a switching regulator The switching regulator is a good recommendation for the charger due to high efficiency Noise is not a consideration because the satellite unit would not be transmitting or receiving information when it is docked in the charging station In addition to the basic phone schematic an energy storage unit needs to be added for flexibility in us
172. rom the fingertip or earlobe In a future design the AFE4490 would be re introduced or a better filtered and amplified design would have to be used to gather heart rate from the ankle 3 3 4 Body Position Sensor From an overview of relevant technologies consisting of accelerometers gyroscopes and IMU s it looks like choosing a component with IMU functionality will be the best choice for the ability to tell in which position the infant is in during the sleep cycle for the baby peas project IMU s can be extremely costly Through research it was found that accelerometer IC s were more available and low cost with only a few IMU devices in the price range compatible for this project A comparison of the IMU s and Accelerometers for this project will be considered Key factors which weigh on the decision will be accuracy cost size reliability ease of configuration ease of solder ability and of course power consumption Since the baby peas vital signs monitor is going to be wireless and battery powered the two most important factors will be power consumption and accuracy With a wide variety of sensor to choose from a lot of IMU s and accelerometers offer a 36 special function feature which allows the IC to be put into a sleep mode to conserve power Components which offer this feature will be given special consideration 3 3 4 1 Invensense MPU 60x0 series The MPU 6000 and 6050 are IMU s which are integrated onto one chip providing
173. ry function would have to be programmed from scratch taking up a large amount of time and resources to understand exactly how the memory is accessed and displayed Header files also ensure a common base language that can be easily read by the programming population For example the standard input output header file includes a print function called printf This function prints a string to the screen By using standard header files two different programmers can look at the printf function and know immediately what it is doing The alternative would be to have two programmers defining their own print functions and using it in their code The two unique print functions would not only be redundant in the code but might cause confusion between programmers A compiler comes with a number of header files that can be used to begin coding general projects These include the stdio h file and math h file To begin coding for a specific part such as the CC2541 the manufacturer provides a number of header files to use 10CC254x_bitdef h This header file contains the coding that defines the bit definitions of registers in the CC2540 CC2541 Each register in the RAM is located at a specific address in the internal memory This header file defines each location in memory that corresponds to its certain register Comments are provided that explain each definition and that specific register s function in the overall circuitry In addition each bit of the speci
174. s 8 1 Appendix A References 1 Children and Sleep Children amp Sleep N p n d Web 30 Nov 2013 lt http www sleepfoundation org article sleep topics children and sleep gt 2 Understanding Your Baby s Sleep BabyCentre N p n d Web 30 Nov 2013 lt http www babycentre co uk a558727 understanding your babys sleep gt 3 Why Does Your Body Temperature Rise When You Have a Virus Such as the Flu HowStuffWorks N p n d Web 30 Nov 2013 lt http science howstuffworks com environmental life cellular microscopic question45 htm gt 4 How to Take Your Baby s Temperature BabyCenter N p n d Web 30 Nov 2013 lt http www babycenter com 0_how to take your babys temperature_11508 bc gt 5 Motorola A Google Company Motorola_US N p n d Web 30 Nov 2013 lt http www motorola com us other baby monitors 1 gt 6 Philips AVENT Basic Baby Monitor with DECT Technology Toysrus N p n d Web 30 Nov 2013 lt http www toysrus com product index jsp productId 3471724 gt 7 Cole Madilyn New Student Invention to Cut down on SIDS Cases UNIVE RS E N p 29 Nov 2012 Web 30 Nov 2013 lt http universe byu edu 2012 1 1 29 new student invention to cut down on sids cases gt 8 Gallagher Alisha News While You Were Sleeping Monitor Alerts Parents If Baby Stops Breathing N p 26 Nov 2012 Web 30 Nov 2013 lt http news byu edu archive12 nov studentinnovator aspx gt
175. s a neat feature which allows the chip to go into a sleep mode when no motion is detected and has an adjustable threshold for when the chip should be woken up This way if the infant is motionless there is no need to run the accelerometer during motionless states The User Interface can recall the 38 previous data until the baby moves again and causes the chip to wake up and begin another sample to re adjust the position and update the user if the baby has turned to a harmful state position This could boost battery life r m i Figure 13 Possible PCB Layout for the ADXL362 Figure 13 of the possible PCB layout for the ADXL362 are the outer dimensions and recommended PCB layout design from Analog devices The package is small at 3 5 x 3 5mm denoted by A X B 16 pin LGA package with recommended trace widths of 3mm denoted by a The device could prove to be difficult to solder because of its LGA Land Grid Array package Soldering down the component with a soldering iron is not possible so it would have to be down with a solder reflow machine or hot air pencil Another negative to the LGA package is there is no way to tell if the part is soldered down correctly This could prove difficult during debugging of the system and rework if the part needs to be replaced The part costs roughly 10 dollars from Digikey and is stocked and ready for delivery 3 3 4 3 Freescale Semiconductor MMA8451Q The MMA8451Q accelerometer is low power and
176. s a precision analog to digital converter that comes with an 8051 microcontroller core and flash memory The analog to digital resolution is 24 bits with 22 bits effective resolution at 10Hz and a low noise level at 75nV The MSC1210 has 8 different ADC differential single ended channels Other features include an on chip temperature sensor and burnout sensor detection The memory capability is up to 32KB flash memory and 1 28KB SRAM There are 34 total Input Output pins and a 32 bit accumulator Serial and parallel communications are supported in the form of full duplex dual USARTs and Master Slave SPI This model operates on a range of 2 7V to 5 25V with a low power output at 4mW Idle mode current is less than 1mA and Stop mode current is less than 1 A 27 Advantages of the MSC1210 e Serial and parallel communication e On chip temperature sensor and burnout sensor e 8051 microcontroller core e High analog to digital converter precision The general characteristics of the preceding microcontrollers have been presented and were considered as viable implementation options for the project The chosen microcontroller is the CC2541 for its convenient Bluetooth SoC solution and acceptable CPU parameters 54 After Senior Design our implementation utilized the CC2541 but with the difficulties of implementation the Atmel Atmega328p was implemented due to the ease of use and the Arduino Development environment compatibility 3 3 8 Power Supply 3
177. s at 16 MHz with a 250 ns instruction cycle There is up to 4K x 14 Words of Flash Program Memory and up to 256 bytes of RAM Operating voltage range is 1 8V to 5 5V The PIC microcontroller also has multiple low power settings Standby mode typically runs at 50 nA at 1 8V Operating current is 100 uA The watchdog timer current is another low power feature that operates at 500 nA at 1 8V This microcontroller features 17 input output pins and 1 input only pin The analog to digital converter has an 8 bit resolution with 12 separate channels It supports Asynchronous Receiver Transmitter AUSART SPI Master Slave and I2C Slave data communication options 29 The advantages of the PIC16F720 e Low power usage e Cheap powerful microprocessor e Sufficient memory space e Sufficient amount of I O pins e RISC architecture o Reduced instruction set o Faster computations 3 3 7 4 CC2541 The CC2541 is a true system on chip SoC solution for Bluetooth low energy applications Another feature of the CC2541 is the Bluetooth system located on the chip which supports 250 kbps S500 kbps 1 Mbps and 2 Mbps data rates The microcontroller core is an enhanced 8051 MCU The 8051 microcontroller has a computer speed of 33MHz and MIPS at 8MHz It uses 8 bit architecture The memory contained within the 8051 is up to 32KB flash memory and up to 1 2KB RAM There are up to 8 analog to digital converters at a resolution of 24 bits It supports SPI IC an
178. s such as safety security and responsiveness a baby monitor requires the highest standards for human computer interaction HCI For Baby Peas ground station unit a number of choices exist the three most common ones are simple embedded LCD screens desktops and smart phones While the first option embedded LCD screens would be the cheapest selection it also tends to be the least attractive and least consumer friendly Intended for a more industrial settings or niche markets these screens would not function well for the needs of a baby monitor The chance of missing critical information undermines the safety and security goals In addition having a separate ground station to the peripheral ankle mounted sensor generates more clutter in the unit Parents of newborns would surely appreciate any effort in removing clutter Option two desktops has much potential and offers a greater power in applications and calculations In addition most households that would purchase the Baby Peas unit would have some version of a home pc However it does not matter how powerful the unit is if the unit lacks ergonomics Having mobility in baby monitors trumps the desktop option leaving smart phones as the best option having both clarity and mobility Despite the obvious suitability of cell phones or tablets LCD with resistive touch and personal computer options are still considered for the developmental portions of the peripheral sensors and microprocessor
179. s t4 ts and t describe the time necessary to send out the data bit through the bus The parameters te and tio are the time it takes either the master or slave device to set up the response signal to send the bit The corresponding t7 and ty describe the time needed to hold the signal high to confirm the state of the signal If the signal flips quicker than the hold time the sent bit may be untrustworthy data The duty cycle of both the master and slave serial clock is 50 percent figures 53 and 54 below show the SPI master and SPI slave AC characteristics The top waveform is the serial clock signal Shown in this diagram is one rising edge and one falling edge The second waveform is the select slave signal The selection signal is low to indicate the bus is clear to transmit The master output device has the data bit DO ready to transmit The master device inputs the bit as shown in the bottom MISO waveform The master device also presents its own data bit for output to the slave device This is shown in the third MOSI waveform eeo de gt ala pj ls gt MISO Figure 52 First SPI Waveform Reprinted without alteration with permission by Texas Instruments The second figure shows the same configuration and data transfer concepts except from the perspective of the slave device It makes sense that both the master and slave devices will have the configurations A difference in timing can result in a data transfer error w
180. s validates the TPS62740 is in Vin on the TPS62740 Ov circuit and verify battery is shut down mode during charging and proper battery charging via digital multimeter operations and the battery is charging operation is charging properly observed Table 27 Battery Regulator and Charging circuit Test Matrix 6 1 1 1 Temperature Sensor Hardware The temperature sensor will be the next system to be tested on the PCB For all the peripherals the Atmega328 software code will have to be completed and debugged at the same time as the peripherals are being added Once this is completed the data communication I C can be probed and evaluated using an O scope to check the SDA SCL and Chip select lines are operating properly For the hardware test the output of the data from the TMPO06 is inconsequential Hardware testing is making sure the device operates under the specifications in the data sheet Table 28 below transitions Test Procedure Description Expected Result 1 Proper Solder Measure the input resistance on This verifies the component Voltage High impedance connections Vin pin to ground with a DMM input is not shorted and should operate properly when powered 2 Chip Select Line Measure the chip select line with This verifies the ouput from the CC2541 High low transitions an O scope to verify proper high is controlling the chip select line from Ov to VDD low transitions square wave 3 SDA SCL line test Measure the chip sele
181. stem test parameters which have to meet a certain criteria before the product could be labeled as a success To such an end the Baby pea s project will take time to layout the PCB in a specific way which allows each sub system to be connected and disconnected from the CC2541 and power supply circuitry through the use of series O ohm resistors This way each sub system can be connected and tested separately from all other interactions with other subsystems This will allow individual sub systems to be brought up to specifications and debugged easily Any dysfunction can be located in a timely manner and either switched out or replaced with another component After all subsystem categories completed testing one subsystem at a time will be added in and retested for compatibility The test equipment used for evaluating the hardware will be oscilloscopes function generators digital multimeters power supplies spectrum analyzers and logic analyzers All the testing will be done with electrostatic protection in mind 6 1 1 Battery Regulator and Charging Circuits The first circuit to be tested is the battery regulator and charging circuit To test this circuit the TPS62740 will be soldered onto the PCB first with supporting circuitry CC2541 will also be soldered to the PCB On the switched output of the regulator there will be a O ohm series resistor which will not be placed This will allow isolation to the rest of the PCB and an external dummy lo
182. stems will be the different sensors attached to the central system This includes the pulse oximeter sensor body position sensor and temperature sensor Each of these components will obtain and consolidate their own data which will be sent to the central microcontroller The CC2541 will then have to organize that data from multiple sources within its memory The data will then be sent out to the user interface through the Bluetooth SoC module The CC2541 will continuously communicate with the user interface This way the data from the peripheral units will be constantly updating the display on the smart phone Input from the user will also be sent from the smart phone to the microcontroller via the Bluetooth wireless connection Considering the data transfers that are necessary for the project to work an outline of the software functions and header files can be created A huge emphasis will be put on data communication between peripheral components the central microcontroller and the user interface Therefore a number of functions must be defined that transfer data from the input pins connected to the peripheral components to a predetermined area in the internal RAM Each of the external components will need to have their own area in memory to write to Another group of functions will regulate the transfer of data from internal memory to output of the MCU This will ensure consistency in the output of data to the correct output pins so as not to conf
183. t cramirez36 cfl rr com gt Date Saturday 23 November 2013 3 43 PM To Steven Keeping lt steven keeping nordicsemi no gt Subject nRF51822 permission to use diagrams and figures from data sheet Hello My name is Christopher Ramirez and I m an electrical engineering student at the University of Central Florida I m currently working on our senior design project documentation We are designing a vital signs baby monitor which wirelessly transmits heart rate position and temperature of an infant while sleeping Of course we won t be testing this on any infants but we are looking at using the nRF51822 for our wireless communication to a smart phone or other peripheral device We were hoping we could get permission to use some of the layout diagrams in our senior design document Our design will not be used for consumer use and none of the diagrams or figures will be altered We will also properly cite Nordic Semiconductor for any information we use from the data sheet Thanks for your time Happy Holidays Christopher Ramirez 2 Freescale Semiconductors From Freescale_Customer_Supply freescale com mailto Freescale_Customer_SupplyOfreescale com Sent Monday November 25 2013 5 27 PM To cramirez36 cfl rr com Subject RE FSL SR 1 1214068461 Permission to use graphs figures tables information 132 Dear Christopher Ramirez Of course you can make reference to our documentation however we are not lable in any
184. te the PCB for any mistakes which could hinder the assembly of parts onto the board Custom Circuit Boards will be approached once the PCB layout design is completed to receive a price quote Once completed it will be a backup plan in case schedules start to become a problem and a PCB is needed quickly 109 5 2 2 PCB Assembly Houses For the PCB assembly the Baby pea s project wanted to approach local PCB assembly houses which provide component assembly to PCB services Two local companies were researched as possible candidates for assembly of the PCB due to the small nature of QFN package devices Pricing and turnaround times will be the driving factor in choosing an assembly service 5 2 2 1 QMS Quality Manufacturing Solutions Quality Manufacturing Solutions is a local PCB assembly house located in the Lake Mary Fl area which not only provides PCB assembly services but a host of engineering manufacturing test configuration control quality and supply chain management services to their customers They specialize in rapid prototype to medium volume production They have the ability to perform BGA rework and X ray services if needed Judy Kelch is a project manager at QMS and will be approached for sponsorship options with the Baby Peas project which could involve financial contributions or design advice for PCB layout and inspection services of the solder connections Pricing for QMS to perform a pick and place operation and run the boar
185. ters and transfer count Each channel is configured with DMA descriptors Can be located anywhere in memory o Accesses data using XDATA memory space allowing access to all physical memories o Many hardware peripherals are used with the DMA controller e Interrupt controller o Controls 18 interrupt sources o Further divided into 6 interrupt groups o 4 interrupt priorities o TO and sleep timer interrupt requests work when the CC2541 is in power mode 1 or 2 sleep mode to bring it into active mode e Debug interface o Two wire serial interface o In circuit debugging o Capable of erasing or programming the entire flash memory o Stop start execution of user program o Execute 8051 core instructions o Set code breakpoints o Single step through code instructions e I O controller o Controls all general purpose I O pins o CPU assigns control of pins to peripheral modules or software o Assigns input or output configuration of pins o Connects pullup pulldown resistors o Peripherals can choose between two I O pin locations e Sleep Timer o Ultralow power timer o Uses either external 32 768 kHz crystal oscillator or internal 32 753 kHz RC oscillator o Runs continuously in all modes except power mode 3 e Watchdog Timer 80 o Allows the CC2541 to reset itself Timer 1 o 16 bit timer o Timer counter PWM functionality o 16 bit period value o 5 individually programmable counter capture channels Timer 2 o 40 bit timer o 16 bit counter and 24 bit overf
186. than 1 uA The Figure is configured to 5 volts output This voltage regulator comes in a host of different voltage levels including 1 2V 1 5V 1 8V 2V 2 5V 2 8V 3V 3 3V and SV While the TPS62740 is the ideal regulator for the project a backup regulator has been chosen in the event TPS62740 does not work as promising as it looks on paper As discussed earlier in the section on regulator background switching regulator due to the frequency at which it opens and closes a switch can interfere with radio frequency signals In the case that the signal is noisy and the problem is determined to originate from the switching regulator a possible replacement linear regulator will be used The recommended linear regulator is the LT1761 3 3 According to the datasheet on Linear Technology s website this is a low drop out voltage regulator with low noise design Figure 23 shows the curve of typical drop out voltage in regards to the differing output currents For Baby Peas output current can range from 50mA to over 100mA At the lower end of that spectrum 250mW differential will be required from the input to the output While not ideal this is very low for a linear regulator At the higher end of the spectrum the cost differential is higher This is why the linear regulator is the backup choice Despite the cost the LT1761 is still lower than most of the competitors Dropout Voltage mV 350 4 300 250 4 200
187. that immunization can reduce the risk of SIDS by 50 6 e Do not expose the baby to second hand smoke In summary due to the varied factors of sudden infant syndrome it is difficult to pinpoint the exact cause and remove that cause If all the environmental causes are removed the baby could still have a defective arcuate nucleus If the arcuate nucleus is the culprit there s also hyper or hypothermia As such while it is possible to try to remove all factors that can contribute to SIDS it is difficult to make sure that all factors are completely removed Instead of preventing by factors prevention by monitoring and alertness is the best method due to the dynamic nature of the prevention Baby peas monitoring system will offer a four pronged approach to help with monitoring factors that affect SIDs Temperature pulse rotation and oxygen parameters touch on all of the risk factors mentioned above Having an empirical data stream of these factors could allow the caretaker make a much better decision on the wellbeing of the child 3 2 1 3 Vital Signs Vital signs are the initial measurements which represent the general health condition of an individual The four main measurements in most medical settings include body temperature heart rate respiration rate and blood pressure Pain level blood oxygenation may also be included if the appropriate medical devices are available The Baby Peas project aims to provide parents with reliable conv
188. the above paragraph The max range is approximately 100m Data rates of 1 3Mbits s It s voice capable but takes around 100ms to transmit data packets Its peak current consumption is around 30mA 3 2 5 1 2 Bluetooth Low Energy Bluetooth LE is the newest version of the Bluetooth standard It can also be called Bluetooth v4 0 and Bluetooth Smart It has some stark differences between previous versions One of them is Bluetooth LE is not backwards compatible with previous 17 versions of Bluetooth Bluetooth LE hardware is different from previous versions It still uses the same topologies but Bluetooth LE is geared heavily towards low energy consumption It has a reduced range of 50 meters which still meets our range specification While it still uses GFSK modulation the LE version does not transmit on 79 channels but rather on 40 channels which are 2 MHz wide It has a maximum transmit power out of 10mW The data transmit rate is 1Mbit s but the transmit time is only 6ms which contributes to less power consumption Most LE devices operate in single mode which means they only operate using the Bluetooth LE protocol stacks but there are devices which are dual mode which means they can operate either Bluetooth Classic or Bluetooth LE These devices are called Bluetooth Smart Ready 30 Pros Extremely Low Power Consumption Battery life using a CR2032 can last up to a year in some applications Data Rates needed meet specifications Protocol
189. to the scalability for future boards While current modules on the Baby Peas require voltages around 3V the future iterations or different models could require less or more voltage For example the pulse ox unit raises the voltage requirement for the entire unit The accelerometer and temperature sensors hover around 2 75 for voltage requirement but the pulse ox require a 3 3 3V input If a baby peas unit was built only around the accelerometer and temperature the regulator could be configured to select only pins VSEL 4 and VSEL2 That could length the battery life by a magnitude The ability of the pin select allows the designers to choose the best output voltage for the system Currently for the Baby Peas unit all the VSEL pins VSEL1 through VSEL 4 are going to be pulled high so the output voltage of the TPS62740 is going to be at 3 3 The overall efficiency of the regulator TPS62740 when all the VSEL pins are pulled up for an output of 3 3V is given in figure 34 As you can with the button batter LIR2477 the efficiency curve lies somewhere between the green and orange curve The LIR2477 outputs 3 7 potential This is close to a 95 percent efficiency meaning 66 OUT VSEL3 o o o o o Ji o 1 0 o o o o o a 1 o o TPS62740 a ae EI ECOS CI CS 27 1 Jo jo Ji 28 1 0 1 JO 29 11 0 1 01 30 j 1 O Jo 31 1 1 O 1 32 1 J1 fji i Ja ff Ja Table 18 Different Voltages Based on the Selection of the Pins with the Highlighte
190. tor my child window which shows all Body Position and 4 sensors bemg Temperature are all monitored and their displayed in the diplay respective information device window Shutdown A stop operation is made by Verifies the application Application closes the user and Shutdown can be disabled and device is chosen closed out Table 32 User Interface Software Test Matrix 6 3 System Level Testing System level testing can be completed once all the individual subassemblies are proven to be operating properly System level testing verifies our project meets all the design parameter specifications and goals required to be a successful product System level testing also needs to be tested in a variety of scenarios to allow for proper testing of the different situations which may occur during the night 1f the product were to be placed on a sleeping child While child testing will not be taken the peripheral device will be worn by the project members and monitored throughout sleeping to validate some of the tests Most of the tests can be accomplished in a lab environment Environmental temperature testing will occur at L 3communication Cyterra division in South Orlando They have 116 graciously allowed the baby peas project to utilize their temperature test chambers for environmental test validation 6 3 1 Skin Temperature Final Test Skin temperature final testing will be accomplished by connected the peripheral sensor onto a group memb
191. tors such as pulse temperature weight and blood monitors 56 APIs for the health profile include BluetoothHealth BluetoothHealthCallback and BluetoothHealthConfiguration The arrangement of the two devices is of source and sink the source is the measuring device and the sink is the home station that is receiving the data 56 5 Project Prototype Construction and Coding 5 1 Parts Acquisition and BOM 5 1 1 Part Vendors To ensure uninterrupted progress in the project we have to find reliable part and components providers Newark Digikey and Sparkfun are the main distributors along with local hobby stores like Skycraft Part and Supply 5 1 2 Newark Newark Corporation Newark element 14 is an electronic component distributer based in Chicago Illinois Founded in 1934 Newark Electric was a small shop mainly selling radio parts It is one of the major distributors of electronic components and testing hardware today One of the advantages of using Newark is its affiliation with Cadsoft Eagle schematic capture software Cadsoft Eagle has an option provided by Newark which allows the designer once the schematic is complete to assign specific manufacturing part numbers from its database to easily create a bill of material This feature alone could save hours in looking up each individual component on the 3 different websites and then comparing costs Newark provides both the manufacturing part number and the Newark assigned part number T
192. ts the connection the BluetoothSocket is connected and the server side can stop BluetoothServerSocket so additional requests will not be honored Some commands used are listenUsingRFcommWithServiceRecord String UUID accept and close For the first one the string is the name of the service The accept command will initiate connected BluetoothSocket only if the query was accepted Finally the close call sets down the query and no additional connections will be made In the case of multiple satellite units the close call can be adjusted so that more connections can be made To the right is a sample connection code from android developer site Connecting device as client side 105 The ground station must first get BluetoothDevice that represents the satellite device Several commands used are creatRfcommSocketToServiceRecord UUID listenUsingRfcomm WithServiceRecord String UUID and connect Figure 71 below is sample code for Android applications on how the Bluetooth connection could be made The Baby Peas project could use this as a platform in helping the development of the smart phone application 56 Private class AcceptThread extends Thread private final BluetoothServerSocket mmServerSocket public AcceptThread ff Use a temporary object that is later assigned to mmServerSocket because mmServerSocket is final BluetoothServerSocket tmp null try 1 MY UDID is the app s UUID string also used by the client code
193. uld go with the 48 pin QFN package One careful consideration for using this part is an external antenna must be integrated for proper operation to occur Nordic Semiconductor examples for designing an external 50 ohm antenna and the schematics and gerber files are available for download from their website The part dimensions are 6mm by 6mm Figure 22 is the dimensions of the device TOP VIEW BOTTOM VIEW SIDE VIEW Figure 12 QFN48 6x6 mm package 0 80 0 00 4 0 0 35 Min 0 85 0 02 t 0 20 A A E 0 40 Nom 0 90 0 05 ad 0 45 Max OFN48 6 x 6 Figure 21 QFN48 Device Dimensions for nRF51822 Reprinted without alteration with permission from Nordic Semiconductors From Figure 22 all dimensions are in mm The b and E2 D2 values are our main concerns when creating the PCB design The b measurement is very small at 20mm nominal so a hot air pencil or solder reflow machine will be needed The individual pins 50 are visible on the outside of the component which will make realization of good solder connections easier to decipher E2 and D2 are the dimensions of the ground plane which needs a solid solder connection for the device to work properly Nordic Semiconductor states the PCB must have a minimum of two layers and a ground plane for optimal performance PCB specifications can be downloaded at www nordicsemi com to aid in the RF layout and the surrounding components The following Table 16 below is a comparison of the three devi
194. until the data pad direction is changed from input to output Then data can be transferred out from the system CN Command Time Debug Clock caste TO Data l Data Pad Direction _ PM 7 ae o e Figure 62 Typical Debug commence sequence Reprinted without alteration with permission from Texas Instruments 4 1 4 9 CC2541 debug device The CC2541 requires a programming application to implement the software designed to run the microprocessor The CC debugger is a device that is used to run debugging software and for flash programming There are two PC tools that couple with the CC debugger to run the software on the microprocessor the SmartRF Flash Programmer from Texas Instruments and the IAR Embedded Workbench for 8051 from IAR Systems 97 The SmartRF Studio is the preferred PC tool in this project due to the cost of the IAR Embedded Workbench In the beginning the understanding was extremely thin on the use of SmartRF Studio This only allows for projects to be loaded onto the CC2541 rather than a development environment so IAR embedded workbench was used because the code needed to be changed to work with our design The minimum connection for the connecting the CC Debugger to the System on Chip device requires the Debug Clock signal and Debug Data signal connected from P2 1 and P2 2 respectively on the SoC to pin 3 and 4 on the Target Connector Resetn must also be connected between devi
195. urns ventricular fibrillation cardiac arrest and death 42 As table 4 lists a current as low as 5 mA can cause a painful shock to an average adult individual At around 6 16 milliamps the victim will start to lose control of their muscles and this is known as the let go range due to the fact that any higher amperage can cause spastic contraction of the muscle fibers and prevent the victim from letting go of the live wire The range of effects is listed in Table 4 Although fat tissue is a bad conducting material and the baby might be protected somewhat due to high fatty tissue the overall threshold for damaging current level is undoubtedly lowered for a baby due to a much lower body mass A shock that will not cause lasting effects in an average adult can irreparably harm a child According table 4 a current as low as 100 milliamps can cause ventricular fibrillation in healthy adults That is enough to kill the said adult In a child with a mass order of magnitude smaller than a healthy adult the100 milliamps potentially becomes lethal by the same order of magnitude In addition even if the shock does not cause visible signs the perception level will cause discomfort to the baby For a portable circuit there 1s no way to bond the circuit to an effective ground fault path If the unit inadvertently gets knocked around and expose circuitry the baby might very well exposed to a lethal current and the 23 Current Level in Probable effect o
196. use the data that shows up on the output display For example if the data from the temperature sensor accidentally ended up be sent to the output for the pulse oximeter the user might interpret the data as their child being in danger The coding that dictates the techniques for accessing the memory can be grouped together as memory management functions Any change or access of memory will be tracked and monitored by these functions Another set of functions will handle interrupts in processing priority Interrupts will come from either the central computing unit or from the user The interrupt functions must be created to deal with a range of interrupt scenarios A couple scenarios might be that an alarm is triggered or the user requests specific historical data at a time A final group of functions will deal with instructions coming from the user Input requests originated from the GUI must be interpreted on the mobile phone application and sent to the microprocessor to be executed by these functions Each group of functions can be described as a class Each class will also include multiple functions to check for legitimate function execution to ensure there isn t 91 a mistake in the coding These will act as debugging functions that will seek out any flaws in the programming and correct them Header Files The header files are the pre coded portions of C code that are used to define basic functions and type definitions Without header files eve
197. user interface Table 38 Software Tasks Milestones Chart Senior Design 1 In addition to the hardware schedule the software schedule for senior design 1 was a rough guideline for the development life of this product Like the hardware schedule the software also starts by researching through similar projects This was to gain both an understanding of the available resources and also help formulate the framework for this project In addition to software research the group needs to learn some sort of object oriented language as most of the mobile platforms operate on object orient languages such as Java or C As the group is composed of electrical engineering students who have a foundation in C and little to no experience in object oriented programming this is a critical step in the developmental cycle In addition while the prototype will not be built until second semester of senior design it is feasible to look for development kits to 121 test out the software portion Usually companies such as Texas Instruments or Freescale will have developmental kits for developers and hobbyists to write applications for Below are tables 39 and 40 for the milestone charts and weekly schedules for Senior Design 2 Spring 2014 l6 Dec 30 Dec 13 Jan 27 Jan 10 Feb 24 Feb 10 Mar 24 Mar 7 Apr 21 Apr Hardware Tasks W1 2 W3 4 W5 6 W7 8 W9 10 W11 12 W13 14 W15 16 W17 18 W19 20 Order Long Lead Parts Order Common Parts PCB design Layout PCB Design Review PCB for
198. usually consist of two shift registers set up in a circular buffer The SPI bus is programmed to send a predetermined amount of data per transmission At the end of the entire cycle the slave device register will have the data from the master device and vice versa This setup is full duplex since data is being passed between the master and slave device Figure 52 is an example of Master Slave interactions and shift registers Master Slave Figure 51 Master Slave Interactions Reprinted without alteration with permission from Texas Instruments Table 21 below lists the AC characteristics of the CC2541 for the SPI data bus The parameters for each of the variables t are shown in table 21 and in figures 54 and 55 Test Conditions Master RX and TX o Slave RX and TX SCK duty cycle Master a Nvo nci Slave i Master t SCK to SSN high Slave Master load 10 pF Master load 10 pF Slave Slave Slave Slave load 10 pF Master TX only Master RX and TX Slave RX only Slave RX and TX Table 21 AC characteristics Min Typ Max 250 250 Unit 50 N N N gt nin pa UN IA IA IVAN IM _ UI DADO O Gd Gd Go Go ey Elo lies 5 UN T N Operating Frequency 4 85 The SCK period is the set period coming from the master device namely the CC2541 Parameters tz and t are the time it takes the master device to respond to the slave select signal notification Parameter
199. vasive and wireless technologies they do not provide the necessary tools for gathering heart rate oxygen levels and skin temperature but do provide baby positioning information if a video option is taken Although a product offering a video monitor does not provide positional data unless the user is explicitly looking at the video screen of the monitor Thus the user could be unaware of the position of the infant because the display device will not actively warn when the infant has turned to the side or stomach So to avoid the clunky and extremely evasive technique used in hospitals and doctor offices wired the project has to use a wireless technology to be able to monitor the sensors implemented without much intrusion In doing this some hurdles must overcome There are 8 main areas of concern to include battery life range data transfer rates data security ease of implementation according to project schedule limits heat dissipation and network topology constraints Finding a wireless technology which supports all these features in an advantages way requires consideration of all relevant wireless technology and a final comparison to see which one fits best for the specifications and cost requirements 3 2 5 1 Bluetooth Bluetooth is another widely used wireless technology It like WI FI utilizes a Master Slave network Bluetooth can have master and 7 slaves which are formed into a piconet 30 It has an IEEE 802 15 1 standard protocol certi
200. ve 90 of document done Have 100 rough draft done and edited A ame Table 37 Hardware Tasks Milestones Chart Senior Design 1 120 The hardware portion schedule is primary driven by research on three sections sensor components central processing unit and power unit The sensor component and the microcontroller that controls them should be researched and procured in conjunction with each other as both will have to mesh for the entire unit to work Power source research must wait until the parameters for each sensor the central processing unit and wireless protocol are determined In addition to the component selection the hardware schedule also includes the documentation required at the end of senior design 1 This massive document will require a lion s share of work and work needs to start on that as soon as possible 5 Aug 2 Sep 16 Sep 30 Sep 14 Oct 28 Oct 11 Nov 25 Nov 2 Dec Software Tasks W1 2 W3 4 W5 6 W7 8 W9 10 W11 12 W13 14 W15 16W17 18 W19 Research similar projects Determine appropriate platform for development Determine appropriate language for development Look for code resources for similar projects Order sensor tag from TI Understand the loading mechanism for android Run sample code on galaxy nexus Have successful handshake with developmental kit Start parsing through existing code Start writing code specific to Baby peas Have user interface design started Have working
201. way for th use or missuse of it attached to this e mail l m sending you an executable file including the tables from Apendix B which assume ar ethe one syu need all the schematic files are icluded in compressed file AN4327 zip please read carefully the disclaimer and make sure you fully understand its implications and limitatioms the disclaimer will pop up once you execute the file had to chage the file s extension from exe to doc in order to avoid rejection from your e mail filter just change it back and you will be able to use it hope you find this information useful Shall any question arise feel completely free to contact me through this service request Thank you for your interest in Freescale Semiconductor products and for the opportunity to serve you Best Regards Augusto Panecatl Technical Support Freescale Semiconductor This message has been sent in reply to the following service request SR Number 1 1214068461 Date Opened 20 Nov 2013 04 01 33 PM Subject Permission to use graphs figures tables information Description Hello My name is Christopher Ramirez and am currently a student at the University of Central Florida I m in Senior Design 1 and we are designing a device which monitors infant heart rate and transmits the data over bluetooth to a smart phone We have a senior design paper to write and was hoping we could have permission to use some of the figures tables and graphs from the ANA432
202. wer longevity of operating hours easy and fast recharge time and noninterference with the other modules on the unit 3 2 9 1 1 Safety Safety is first and foremost due to the sensitive nature of the environmental conditions during operation The satellite unit not only functions in close proximity to humans 1t is primarily designed for users with limited verbal communication making it hard for the caretaker to gauge feedback on operation and physical status of the unit in the event of a malfunction In the worst case scenario a runaway heating issue could cause burns on the baby or a shock hazard could happen and cause irreparable damage The unit has to have safety measures in all aspects taking in considerations such as shorts and unduly dissipation Admittedly there is little chance for arc flash or arc blasts due to the voltage being less than 240 according to the National Fire Protection Association 42 The baby pea unit itself limits the voltage to a much lower 3 7 volts However since the unit is worn against the skin electric shock and thermal damage does exist In addition it is not the voltage that is the primary concern but the delivered amperage that can harm or kill a person According to an Ohio State University resource a shock as low as 10 milliamps can cause a painful shock to an adult Lethal currents occur starting at 100 mA Some of the symptoms of electric shock include muscle paralysis difficulty in breathing severe b
203. will have enough space on the PCB to also utilize the TMP103 by Texas Instruments Texas Instruments TMP103 is a four ball wafer chip scale package features two wire interface digital output temperature sensor that may be used for Baby Peas monitor The simple and straight forward design is easy to integrate with Atmega328p The interface is I2C and SMBus protocol In the schematic diagram shown in Figure 45 the supply voltage 3 6 V 1s connected to V port and ground has been connected The resistor 1s recommended to have value equal or less than 5 K Ohm and capacitor in parallel value of greater or equal to 10 nanofarad Because of the simplicity nature of TMP103 it has low noise level An additional RC filter may further reduce the noise level 4 1 4 Communications Microcontroller Design Due to the nature of the Bluetooth Module and Microcontroller being on the same integrated circuit the communications design and microcontroller design specifications and characteristics will be discussed and explained in the same section 4 1 4 1 Communications The CC2541 was decided at first to be the Bluetooth Low Energy RF module used by Baby Peas project team As in all RF designs careful consideration was adhered to during the layout process to ensure proper impedance matching is upheld on the output RF pins of the CC2541 Figure 47 shows the block diagram for the configuration of the communications section of the Baby Peas project 75 Data Inputs Fr
204. xis plane system Sometimes these axes can be referred to as roll pitch and yaw The Gryo measures the angular velocity in units of degrees per second The Baby pea s project can use this information to determine the position of the infant Gyroscope devices like accelerometers offer analog and digital outputs So the design would be similar either for an accelerometer or gyroscope 3 2 4 3 IMU Accelerometers and Gyroscopes both offer unique measuring tools on their own but looking for a device which combines both into one would be the ideal situation for the Baby pea s project An IMU is such a solution The IMU combines both the accelerometer and gyroscopes functions to provide the designer with 6 axes to derive positional data from Now these calculations can be determined by using both an accelerometer IC and Gyroscope IC on the baby pea s printed circuit board and utilizing the data from both sensors to determine position or a combined one chip solution can be realized which gives a digital output over SPI C or UART to the microcontroller 3 2 5 Wireless Technology One of the striving features for the Baby pea s project was to create something that was non evasive Conventional baby vital sign monitors are almost exclusively wired technology and only available by going to the doctor The commercial industry standard for monitoring anything in the home setting is with video and audio streaming While 16 these are non e
205. yer a certain pressure threshold must be met before the circuit registers the touch In addition the screen might not have as great of a contrast due to internal reflections In addition because the top layer is flexible enough so that it can deform to a closer position with the bottom layer it damages more readily than capacitive screens Finally a resistive screen captures one touch a time and will not support multi touch 49 4 1 5 1 2 Capacitive Touch The capacitive touch has two layers of glass spaced out slightly and coated with a conductor This basically forms parallel plate capacitor As the user touches the screen the capacitance changes and the microprocessor can sense the change in the electrostatic field While the screens look very sharp due to the rigid nature of the two glass layers and lack of deformation from the stylus or finger capacitive touch screens are rather expensive and require the user to employ finger or other conductive material to register touches The other upside of capacitive touch is the ability to multi touch However due to the nature of the project developing a capacitive touch screen would be prohibitively expensive 50 4 1 5 1 3 Touch Screen kits It is recommended to buy a kit rather than develop a prototype touch screen due to cost time and expertise There are several kits available in the market for purchase For example 4D systems makes a resistive LCD that interfaces with a Raspberry Pi a chea
206. you for using TI products You are free to use materials from our datasheet so long as you properly credit TI when doing so and do so without manipulating altering skewing or otherwise misrepresenting the images and figures Have a great evening Regards Siebel Administrator TI Customer Support Americas Customer Support Center 512 434 1560 Ue Engage in the FR iif TI E2E Community Support Forums Ti E2E search for solutions get help and share Community knowledge with fellow engineers http www ti com e2e support http www k ext t1 com sc technical support pic americas htm Tl makes no warranties and assumes no liability for applications assistance or customer product design You are fully responsible for all design decisions and engineering with regard to your products including decisions relating to application of Tl products By providing technical information Tl does not intend to offer or provide engineering services or advice concerning your designs Please do not delete the below Thread ID when replying to this email doing so will delay our response to your inquiry SR THREAD ID Service Request Id THREAD ID 1 K3H2DC 134 THREAD ID 1 K3H2DC From cramirez36 cfl rr com Sent 11 21 2013 08 17 23 AM Cc cramirez36 cfl rr com lt cramirez36 cfl rr com gt Subject GEN Email Technical Support www ti com n a This Email Sent From Email Technical Support http www ti com ww e

BABY PEAS (Pulse Early Alarm Sensor)

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