UM Space REU Final Report
Contents
1. void WriteSinglePATable unsigned char value void WriteBurstPATable unsigned char buffer unsigned char count code for utilities c again some stuff was omitted but is left in the actual code file include utilities h RF_SETTINGS rfSettings 0x08 FSCTRL1 Frequency synthesizer control 10 0x00 FSCTRLO Frequency synthesizer control 0x23 FREQ2 Frequency control word high byte 0x31 FREQi Frequency control word middle byte 0x3B FREQO Frequency control word low byte OxCC MDMCFG4 Modem configuration originally OxCA OxFF MDMCFG3 Modem configuration originally 0x83 0x90 MDMCFG2 Modem configuration originally 0x93 0x22 MDMCFG1 Modem configuration OxF8 MDMCFGO Modem configuration 0x00 CHANNR Channel number 0x34 DEVIATN Modem deviation setting when FSK modulation is enabled 0x56 FREND1 Front end RX configuration 0x10 FRENDO Front end TX configuration 0x18 MCSMO Main Radio Control State Machine configuration Ox16 FOCCFG Frequency Offset Compensation Configuration Ox6C BSCFG Bit synchronization Configuration 0x43 AGCCTRL2 AGC control 0x40 AGCCTRL1 AGC control 0x91 AGCCTRLO AGC control OxE9 FSCAL3 Frequency synthesizer calibration Ox2A FSCAL2 Frequency synthesizer calibration 0x00 FSCAL1 Frequency synthesizer calibration OxiF FSCALO Frequency synthesizer calibration 0x59 F2. lt lt pin_out turn on clk out pin P20UT amp 1 lt lt pin_clk 1 lt lt pin_out turn off everything WDTCTL WDTPW WDTCNTCL volatile int 1 0 j 0 for i 0 i lt 100 i wait a second for the i o to transition loop to print out data for i 0 i lt 16 i 15 i current bit thats being output if 1 output 1 on pin_out otherwise output O on pin_out if data amp 1 lt lt 15 i P2OUT 1 lt lt pin_out else P2OUT amp 1 lt lt pin_out update the clock and wait a short while for the i o transitions P2OUT 1 lt lt pin_clk WDTCTL WDTPW WDTCNTCL for j 0 j lt 100 j P20UT amp 1 lt lt pin_clk 1 lt lt pin_out void InitRadio void Set the High Power Mode Request Enable bit so LPM3 can be entered with active radio enabled PMMCTLO_H OxA5 PMMCTLO_L PMMHPMRE_L PMMCTLO_H 0x00 WriteRfSettings amp krfSettings WriteSinglePATable PATABLE_VAL Here is a flow chart for how the send_tone_with_adc function works 14 7 Appendix C Data collection via arduino Below is the code used to get data off of the CC430 via the arduino There are three pins used The ground pin of the arduino is connected to a grounded i o pin on the CC430 pin 7 is used as input for the clock and pin 2 is used as input for data Also there are two modes by which the arduino sends data over the serial port to the computer One is sensor mod
3. PAtable set to 0x70 820 840 860 880 900 920 940 960 25 870 840 860 880 900 9270 940 960 25 9 EESE o PAtable set to 0x3E PAtable set to 0xB5 6 Appendix B RF tone generation and ADC12 code There are three files used in the RF tone generation code main c utilities c and utilities h main c has the overall structure of the code and calls the utility functions in utzlitzes c The most important function in utilities c is the send_tone_with_adc function which is described in more detail below Code for main c include utilities h void main turn off the watchdog timer WDTCTL WDTPW WDTHOLD send byte OxCC to arduino dataWrite 0x03 0x05 OxCC turn on the LEDs BIT6 on port 3 is the red one and BITO on port 1 is the green one P3DIR BIT6 P1DIR 0x01 setup the switch on pinO and pin7 of port 3 to turn on and off the sensing device P3DIR BITO P3DIR amp BIT7 P3REN BIT7 P30UT BITO P30UT amp BIT7 Initialize the pins for the ADC12 P2SEL BITO pinO is the input P2REN BIT1 pini is connected to ground via pulldown resistor P20UT amp BIT1 sets pini to be pulled down as opposed to pulled up P2DIR BIT7 set pin7 as output P20UT BIT7 turn pin7 on this is to power the switch turn on 2 5V internal reference REFCTLO REFMSTR REFVSEL_2 REFON REFTCOFF setup the ADC12 see datasheet for more info on what settings are used ADC12CT
4. interference The rectifier itself gives an output which is proportional to the amplitude of the incoming wave but this proportionality constant depends on frequency to some small degree Furthermore the rectifier can only reliably measure amplitude if the amplitude is sufficiently high so if the power drop across the rectifier or some other element of the circuit is too great then the data becomes useless Also the resonant sensor itself is very sensitive so it is important to isolate it as much as possible from nearby objects One tool we used to attempt to eliminate some of the interference was a 3db attenuator on the out put of the CC430 RF emitter This helped to remove any part of the wave which was reflected by the resonator and in some cases was had a significant effect Power ve Freq Power ws Freq ait 900 Bao ggg Freq in Mhz Freq in Mhz Data collected with two cables in series Two cables in series a 3db attenuator Power vs Freq Power ve Freq Bao 8 69f0 S46 860 BBO 690g Freq in Mhz Freq in Mhz Bao g Bao 900 Szo 940 9g6 Freq in Mhz Freq in Mhz Data collected with resonator no cables Same experiment but with 3db attenuator A large amount of data was gathered over several days Here is a table that briefly summarizes what sorts of experiments were run on which days jul jull3 Tests with one cable two cables and attenuator Direct connection at different power settings and resonator
5. of digital output pins on the CC430 was used to send data to a computer One pin was designated the clock and the other the data pin and these were hooked up to two digital input pins on an arduino The arduino had code to read the data and then to send it via a serial to usb cable to a computer 3 Results After the sensor was put together several tests were run The most simple and primary test was to just simply check that the resonance curve of the resonator as measured by the sensor matched that of the network analyzer in Chris Ruf s lab Initially it did not and this was because other elements of the circuit were causing interference A lot of time was spent in debugging these issues and characterizing them Once that was taken care of some experiments were run with the resonator dipped into a few types of solvents hexane heptane and toluene Harvey Elliot wrote a report Characterization of a Microwave Resonator in April 2011 in which he describes experiments that he performed on some of the very same resonators that we were using to test our sensor He collected data using a network analyzer on the response of the resonator to the same solvents that we used so his paper was used as both a guide and a basis for comparison to our own results In debugging the sensing device several things were noted The blue cables see picture we were using have some kind of response in the frequency range we are using so they cause some
6. output 0x51 orig RRR AKA RRR k k k Function Definition void Transmit unsigned char buffer unsigned char length void ReceiveOn void void ReceiveOff void void InitButtonLeds void void InitRadio void void InitRadio_pwr int pwr void dataWrite int pin_clk int pin_out int data void send_tone char freg_h char freq_m char freg_l int duration void send_tone_with_adc char freq_h char freq_m char freq_l int duration define PMM_STATUS_OK O define PMM_STATUS_ERROR 1 J K k k kk kk kk RR kk KK K KK x Variable definition typedef struct S_RF_SETTINGS unsigned char fsctrli Frequency synthesizer control unsigned char fsctrl0 Frequency synthesizer control unsigned char freq2 Frequency control word high byte unsigned char freq1 Frequency control word middle byte unsigned char freq0 Frequency control word low byte unsigned char mdmcfg4 Modem configuration unsigned char mdmcfg3 Modem configuration unsigned char mdmcfg2 Modem configuration unsigned char mdmcfgi Modem configuration unsigned char mdmcfg0 Modem configuration unsigned char channr Channel number unsigned char deviatn Modem deviation setting when FSK modulation is enabled unsigned char frend1 Front end RX configuration unsigned char frend0 Front end RX configuration unsigned char mcsm0 Main Radio Control State Machine configuration unsigned cha
7. with without cables or attenuator at different power settings jull4 Resonator without cable Attempts to shift the peak with various objects jull9 RF switch by itself and with resonator jul21 Not entirely sure Probably just more random testing jul22 Full setup of prototype sensor with resonator in beaker Tests done with Hexane 3dbm attenuator used and beakers filled to various levels full quarter etc jul25 Data collected with cables again but this time in the beaker All three resonators were Pe tested when emersed in hexane Some random tests with resl and res2 Resonator 2 tested with heptane and toluene Several runs were done with both fluids at various emersion levels resonator right above fluid just touching slightly below Icm below etc To illustrate the sensitivity at the very tip of the resonator chips here are some experiments done with resonator 2 and hexane The first run was done with the resonator slightly above the fluid and then each successive run was done by lowering it very slightly less than 5mm each time Power vs Freq Power ws Freq Bao 8 69f0 Bao 900 970 940 960 Freq in Mhz Freq in Mhz Bao 8 69f0 afo 6940 Bat ggg Freq in Mhz Freq in Mhz Resonator right below fluid Resonator slightly more below fluid 4 Conclusion The sensor in its current state still needs a lot of work before it can be put to use in the field One very important thing that needs t
8. LO ADC120N ADC12SHTO2 ADC12CTL1 ADC12SHP ADC12CTL2 ADC12REFOUT ADC12MCTLO ADC12SREF_1 __delay_cycles 75 enable the ADC12 so that data capture can be turned on later ADC12CTLO ADC12ENC setup radio SetVCore 2 set the voltage of the radio to 2V ResetRadioCore reset all the settings on the radio InitRadio setup the radio using the settings in utilities c turn on interrupts __bis_SR_register GIE __no_operation volatile int 1 3 k 0 j 0 while 1 depending on the input to Port3 7 turn on off the snow sensor if P3IN amp BIT7 P20UT BIT7 P30UT BIT6 else P20UT amp BIT7 P30UT amp BIT6 turn on the radio at the set frequency and send 1000 bytes of the message bbbbb After first 100 bytes the ADC12 captures the voltage on the rectifier and then after the 1000 bytes are transmitted the ADC12 reading is sent to the arduino send_tone_with_adc 0x20 k 16 i 0x00 1000 Itt if i 16 i 0 k if k 5 k 0 code for utilities h some pieces are omitted as not really relevant but are left in the code as examples of other things that can be done include cc430x513x h define PACKET_LEN 0Ox3C PACKET_LEN lt 61 define RSSI_IDX PACKET_LEN Index of appended RSSI define CRC_LQI_IDX PACKET_LEN 1 Index of appended LQI checksum define CRC_OK BIT7 CRC_OK bit define PATABLE_VAL OxCO O dBm
9. STEST Frequency synthesizer calibration 0x81 TEST2 Various test settings 0x35 TEST1 Various test settings 0x09 TESTO Various test settings Ox47 FIFOTHR RXFIFO and TXFIFO thresholds 0x29 IOCFG2 GDO2 output pin configuration 0x06 IOCFGO GDOO output pin configuration Refer to SmartRFA R Studio User Manual for d 0x00 PKTCTRL1 Packet automation control 0x00 PKTCTRLO Packet automation control originally 0x04 0x00 ADDR Device address 0x30 PKTLEN Packet length 2K 2K 2K AK OK OK 2K 2K K K K OK OK K K FK OK OK K 2K K K K 2K 2K K K K OK 2K K K FK OK OK K FK K K K 2K 2K K K FK 2K OK K K FK OK OK 2K FK K K K 2K 2K K K OK OK OK K K K OK OK 2K OK 2K K OK OK OK K fn Strobe brief send a command strobe to the radio Includes workaround for RF1A7 param unsigned char strobe The strobe command to be sent return unsigned char statusByte The status byte that follows the strobe 2K 2K 2K AK OK OK 2K 2K K K K OK 2K K K FK OK OK K 2K K K K OK 2K K K K OK 2K K K FK OK OK K FK K OK OK OK 2K K K OK 2K OK K K FK OK OK 2K K K OK K OK OK K K FK OK OK K K K OK OK OK OK K OK OK OK K unsigned char Strobe unsigned char strobe unsigned char statusByte 0 unsigned int gdo_state Check for valid strobe command if strobe OxBD strobe gt RF_SRES amp amp strobe lt RF_SNOP Clear the Status read flag RF1AIFCTL1 amp RFSTATIFG Wait for radio to be ready for ne
10. UM Space REU Final Report Eric Haengel August 11 2011 Contents 1 Introduction 1 2 Design and Methods 1 3 Results 4 4 Conclusion 6 5 Appendix A Power Output control for the CC430 radio T 6 Appendix B RF tone generation and ADC12 code 8 7 Appendix C Data collection via arduino 15 8 Appendix D How to put together the sensor 18 1 Introduction The purpose of this project was to develop a prototype sensing device which would be able to measure accurately the dielectric constant of a surrounding fluid over a period of time The ultimate goal is to create an implementation of the device specified in Professor Roger DeRoo s proposal A low cost sensor to quantify spatial and temporal variability of snow packs for SCLP validation In brief this device will be able to measure locally in a snow pack the snow density moisture content temperature grain size and packing density of the snow The device will be small and self contained so that it can be left in a snowy region for some duration of time to capture data The sensor has several components to it the main component being an open circuit resonator tuned to resonate in the ISM band When this resonator is immersed in a dielectric material the change in resonant frequency and Q value can be related to the dielectric constant of that material In this way one can study the properties of a surrounding fluid or snow pack using this sensor Other important components of the
11. ator There are three of them so far The Rectifier and the cable that connects to it The Arduino o N Oo Cr A Q The battery pack and its cable for connecting to the CC430 board 18 9 Lots of alligator clips to connect various components together Here are some hopefully useful pictures to guide someone towards putting together the current version of the device 19 Here is a table of the various chips used and their pinouts 20 ceas0 COCOONS _RFSwiteh OOOO o o Rectifier O vec SSP S end Common grounds SS EN Bis i Yor the mome tie ted fo VOC Here are two pinout diagrams one for each of the two cables ADC12 60 8 B GND CLK DATA TXEN se o Rainbow connector pinout Rectifier cable pinout Finally some notes Make sure to connect power to the rectifier or your data will come out as completely flat every time its very easy to forget To write a program to the board connect it to the programming cable and make sure that the programming cable is connected to the computer Right click on the project folder you wish to compile in the Code Composer window and choose Set as Active Project if it is not already set as the active project The project that is used for collecting sensor data is CC430 ADC12 Once you have done this to upload the program to the CC430 go to one of the menues on the top and click Debug Active Project After everything settles and the pro
12. e and the other is bit mode see code int old_state state int count 0 unsigned int value 0 mode 0 means sensor mode it will output the data in the format frequency voltage where voltage corresponds to the voltage measured on the rectifier mode 1 means bit mode and it just prints out bit by bit the word sent by the CC430 int mode 0O initialize the pins on the arduino void setup pinMode 2 INPUT Data pinMode 7 INPUT Clock 15 Serial begin 9600 void loop read from the clock state digitalRead 7 if clock transitioned read data if state old_state int buf digitalRead 2 if in bit mode just send each bit as it comes if mode 1 Serial print buf keep track of the overall word by setting bits in value if buf 1 value 1 lt lt 15 count else value amp 1 lt lt 15 count countt if count 8 amp amp mode 1 Serial print if count 16 if mode 0 print out the frequency voltage if mode 0 if 2 5 float value 4095 0 lt 5 4 Serial print value is just an integer so convert it to actual voltage Serial print 2 5 float value 4095 0 DEC else Serial print value is just an integer so convert it to the actual frequency Serial print float value 0 1015625 DEC Serial print n value QO count 0 F hold the current stat
13. e so that it can be compared to the old one old_state state The format of the serial output in sensor mode from the arduino is Frequency in Mhz Voltage on rectifier Frequency in Mhz Voltage on rectifier The CC430 constantly sweeps across the frequency range There is a C program which was used to get data from the arduino over the serial port The syntax is resonance serial port output file The output can be graphed with a python program graph res py but any graphing program can be used 16 The python program uses the pybiggles library to graph the data Resonance cpp include lt termios h gt include lt stdlib h gt include lt string h gt include lt unistd h gt include lt fcntl h gt include lt stdio h gt include lt math h gt include lt time h gt int main int argc char argv int fd open argv 1 O_RDWR O_NOCTTY if fd 1 printf Could not open s n argv 1 return 1 struct termios config if isatty fd printf Invalid serial device s n argv 1 return 1 tcgetattr fd amp config config c_iflag amp IGNBRK BRKINT ICRNL INLCR PARMRK INPCK ISTRIP IXON config c_oflag 0 config c_lflag amp ECHO ECHONL ICANON IEXTEN ISIG config c_cflag amp CSIZE PARENB config c_cflag CS8 config c_cc VMIN 1 config c_cc VTIME 0 if cfsetispeed xconfig B9600 lt O cfsetospeed amp con
14. e of around 1V has to be supplied and no more than 50ma at this voltage should be allowed After some playing around we figured out that the PIN diodes can be powered by the digital output pins on the CC430 because when they are used to draw current their output levels drop to around 0 8V which is enough to turn on the RF switch figure out what the attenuation of the switch is again The RF Rectifier The resonator chip has two ports one of which was connected directly to the CC430 RF emitter The other end was connected to an LT C5505 RF Power Detector which outputs a voltage signal proportional to the amplitude of the incomming wave By connecting the output of the LTC5505 to an analog to digital converter the ADC12 module on the CC430 we were able to characterize the response of the resonator at different frequencies Early on testing was done on the rectifier to understand how its output relates to the amplitude of the incoming wave It was found that the output is directly proportional to the amplitude but that the constant of proportionality depends slightly on frequency In the end product an entirely different rectifier chip may be used but in any case it will be important to understand how the rectifier responds at different frequencies 6 00E 02 5 00E 02 4 00E 02 3 00E 02 a 2 00E 02 1 00E 02 0 00E 400 025 03 0 35 04 045 05 055 06 065 OF O75 Plot of voltage output of the rectifier vs amplitude of incoming wave The am
15. fig B9600 lt 0 4 printf Could not set correct baud n return 1 if tcsetattr fd TCSAFLUSH amp config lt 0 printf Error initializing device n return 1 int len 0 char buf 1024 buf 0 1 printf d n write fd argv 2 1 FILE handle fopen argv 2 w int count 0 do len read fd buf 1024 buf len 0 fprintf handle s buf if strstr buf n count while len amp amp count lt 400 17 fclose Chandle close fd return QO graph res py usr bin python import biggles sys handle open sys argv 1 r lines handle readlines lines pop 0 freg amp for line in lines line line replace n if float line lt 500 amp append float line if float line gt 500 freq append float line while len amp gt len freq amp pop len amp 1 while len amp lt len freq freq pop len freq 1 print len amp len freq p biggles FramedPlot p title Power vs Freq p xlabel Freq in Mhz p ylabel Volts p add biggles Points freq amp print max freq amp freqlamp index max amp max amp p show p write_img 400 400 sys argv 1 replace dat png 8 Appendix D How to put together the sensor Here is a list of all of the components of the sensor 1 The CC430 2 The programmer cable The rainbow colored ribbon cable The RF switch The Reson
16. g FIFOTHR pRfSettings gt fifothr WriteSingleReg IOCFG2 pRfSettings gt iocfg2 WriteSingleReg IOCFGO pRfSettings gt iocfg0 WriteSingleReg PKTCTRL1 pRfSettings gt pktctr11 WriteSingleReg PKTCTRLO pRfSettings gt pktctr1l0 WriteSingleReg ADDR pRfSettings gt addr WriteSingleReg PKTLEN pRfSettings gt pktlen void send_tone_with_adc char freq_h char freq_m char freq_l int duration Strobe RF_SIDLE WriteSingleReg FREQ2 freq_h WriteSingleReg FREQ1 freq_m WriteSingleReg FREQO freq_1 WriteSingleReg PKTCTRLO 0x02 WriteSingleReg PKTLEN duration 256 Strobe RF_SNOP unsigned char buffer unsigned char ab volatile int i 0 j 0 Strobe RF_STX while RF1AIFCTL1 amp RFINSTRIFG Wait for the Radio to be ready for next instruction RF1AINSTRW RF_REGWR RF_TXFIFOWR lt lt 8 duration Send address Instruction for j 0 j lt 1500 j dataWrite 0x03 0x05 freq_h lt lt 8 freq_m for j 0 j lt 1500 j for j 1 j lt duration j after 100 bytes turn on the ADC if j duration 100 ADC12CTLO ADC12SC RF1ADINB buffer 1 while RFDINIFG amp RF1AIFCTL1 13 j RF1ADOUTB while ADC12IFG amp BITO dataWrite 0x03 0x05 ADC12MEMO Strobe RF_SIDLE WriteSingleReg PKTCTRLO 0x00 Strobe RF_SNOP void dataWrite int pin_clk int pin_out int data P2DIR 1 lt lt pin_clk 1
17. ject is compiled you will have to either click the green arrow that appears in the debug window or use the shortcut key F8 to actually start the code running on the CC430 21
18. o be done is to design a better resonator chip which would be more suitable to the end goal The frequency band that the CC430 can emit RF tones at is rather limited so the resonator will need to be tuned carefully to resonate in that frequency range whether it is surrounded by air or densely packed snow The resonator will likely need to be very carefully designed with electromagnetic modelling software There are many other smaller issues to be worked on as well such as making the device run on very low power so that it can survive in a snow pack for a long period of time It also is important to figure out how to get the CC430 to reliably transmit receive information over the radio so that a base station can be used to control several sensors remotely It will be nice and much more convenient if the serial communication module on the CC430 is figured out so that an arduino is not necessary to read data off of it Another important thing to consider will be the possible inclusion of an amplifier on one end of the resonator device The rectifier can only reliably measure amplitude of an incoming wave if the amplitude is sufficiently high and this has lead us to at least for now always use the CC430 radio at max power when running the sensor This may not be the ideal situation if we wish to conserve power over time it may be more efficient to run the radio at low power but to use an amplifier to boost the output of the resonator Two more sen
19. or data transmission between devices not for continous tone generation It took some toying around and work to figure out a way to make it generate a tone but we were eventually successful The CC430 is able to enter infinite packet length transmission mode if certain registers are set in the right way and by sending a null packet the CC430 will emit a continuous tone at a set frequency see Appendix B It is also possible to control the power level of the output of the device but this is also a bit complicated see Appendix A The RF switch Inthe end product the RF transmitter on the CC430 device will have a dual purpose It will be used to generate an RF tone to measure the resonant peak of the resonator and it will be used to send receive information to from a base station In order to have both functions available it is necessary to have some kind of switching device on the RF transmitter which can be used to turn on or off the antenna and resonant sensing device Professor DeRoo designed such a switch and created a small chip that can do this by using two RN731V PIN diodes When DC current flows through one of the PIN diodes on the chip RF signals are able to transmit through it but when there is no DC current flow then the PIN diode allows no transmission One of the problems in getting the switch to work however is that it has a fairly specific power input requirement In order to get the PIN diodes to transmit a voltag
20. plitude of the incoming constant frequency wave was measured with a high quality RF power sensor The Sensor Code The CC430 microcontroller has on board a 12bit analog to digital converter and this was used to capture the output from the RF rectifier A basic flow diagram of code used for sensing is below The CC430 sends 100 bytes of a null message at a set frequency and then the ADC12 is turned on to capture the voltage of the rectifier The CC430 continues to send another 900 bytes of a null message and then waits for the ADC12 data to be available It then sends this data then to a computer picks a new frequency and repeats In this way the device sweeps through the entire frequency range within a about a minute and by using a program on the computer to store the output as it comes it is possible to create a graph of the response of the resonator at different frequencies see Results Data Output The CC430 actually comes with several ways of implementing serial communication so that it can communicate with a computer For example there is an entire module on the CC430 dedicated to UART serial communication However the CC430 does not come with a logic level conversion chip and RS232 uses a very different set of voltages than the CC430 so one had to be purchased separately Near the end of the project we did purchase such a chip but it has yet to be implemented In the mean time a really simple hack with a couple
21. r foccfg Frequency Offset Compensation Configuration unsigned char bscfg Bit synchronization Configuration unsigned char agcctrl2 AGC control unsigned char agcctrli AGC control unsigned char agcctrl0 AGC control unsigned char fscal3 Frequency synthesizer calibration unsigned char fscal2 Frequency synthesizer calibration unsigned char fscal1 Frequency synthesizer calibration unsigned char fscal0 Frequency synthesizer calibration unsigned char fstest Frequency synthesizer calibration control unsigned char test2 Various test settings unsigned char test1 Various test settings unsigned char test0 Various test settings unsigned char fifothr RXFIFO and TXFIFO thresholds unsigned char iocfg2 GDO2 output pin configuration unsigned char iocfg0 GDOO output pin configuration unsigned char pktctrl1 Packet automation control unsigned char pktctrl0 Packet automation control unsigned char addr Device address unsigned char pktlen Packet length RF_SETTINGS void ResetRadioCore void unsigned char Strobe unsigned char strobe void WriteRfSettings RF_SETTINGS pRfSettings void WriteSingleReg unsigned char addr unsigned char value void WriteBurstReg unsigned char addr unsigned char buffer unsigned char count unsigned char ReadSingleReg unsigned char addr void ReadBurstReg unsigned char addr unsigned char buffer unsigned char count
22. sensor include a temperature sensor a diode photo detector pair to measure snow density and grain diameter and an RF transmitter to contact and send data periodically to a base station Significant development was only made on the open circuit resonator component of the sensor 2 Design and Methods The MSP430 _ In order to create a standalone device which could measure the resonant frequency of a resonator a stable microprocessor capable of controlling an ISM band RF transmitter was necessary After some shopping around it was decided to use TI s CC430F5137 which is a relatively new device that integrates an MSP430 microprocessor and a CC1101 RF transmitter onto the same board This device is able to transmit in three seperate frequency bands but as for the band relevant to this project it is able to transmit between around 820mhz and 960mhz with a resolution of less than 1mhz More specifically the device we used was the EMCC430F5137 development kit which included two boards two antennae two battery packs and some pin headers The cost of this develoment kit was 150 and the programming cable the MSP FET430UIF cost another 100 The RF transmitter The next step was to get the CC430 to act as a controllable RF tone generator but this was not the purpose that the CC430 was designed for If one reads the user guide for the CC430 it becomes clear immediately that the main purpose of the RF transmitter on the CC430 is f
23. sing components need to be worked out as well the temperature sensor and the packing density grain diameter sensor These are theoretically simpler to implement than the resonant sensor but will still require some amount of work More details on how these components will work can be found in Professor DeRoo s proposal 5 Appendix A Power Output control for the CC430 radio In order to control the power output of the RF module on the CC430 a register called the PAtable must be set The PAtable actually have eight channels and there is another register that allows one to choose which power setting is actually put to use but so far it hasn t been necessary to make use of this feature The way that the register value corresponds to output power works is a bit unclear and complicated but luckily some nice person wrote a report TI report swral51la which lists the various output powers one should expect for different PAtable values The output power of the RF emitter is frequency dependent and this may be an important fact to consider later Below are some graphs of frequency vs emitted power Note that a 30dbm attenuator was used so as to not overload the expensive RF power measuring device 18 4 30 gg ttl 840 860 880 900 920 940 960 255820 840 860 880 900 920 940 960 18 8 30 4 19 30 6 EE g C O 19 2 poo Ea 30 8 E m 194 31 O 19 6 O 31 2 m 19 8 314 20 3 L6 20 2 oO 316 E 20 4 32 PAtable set to 0xC0
24. teRfSettings RF_SETTINGS pRfSettings WriteSingleReg FSCTRL1 pRfSettings gt fsctr11 WriteSingleReg FSCTRLO pRfSettings gt fsctrl0 WriteSingleReg FREQ2 pRfSettings gt freq2 WriteSingleReg FREQ1 pRfSettings gt freq1 WriteSingleReg FREQO pRfSettings gt freq0 WriteSingleReg MDMCFG4 pRfSettings gt mdmcfgA4 12 WriteSingleReg MDMCFG3 pRfSettings gt mdmcfg3 WriteSingleReg MDMCFG2 pRfSettings gt mdmcfg2 WriteSingleReg MDMCFG1 pRfSettings gt mdmcfg1 WriteSingleReg MDMCFGO pRfSettings gt mdmcfg0 WriteSingleReg CHANNR pRfSettings gt channr WriteSingleReg DEVIATN pRfSettings gt deviatn WriteSingleReg FREND1 pRfSettings gt frend1 WriteSingleReg FRENDO pRfSettings gt frend0O WriteSingleReg MCSMO pRfSettings gt mcsm0 WriteSingleReg FOCCFG pRfSettings gt foccfg WriteSingleReg BSCFG pRfSettings gt bscfg WriteSingleReg AGCCTRL2 pRfSettings gt agcctr12 WriteSingleReg AGCCTRL1 pRfSettings gt agcctr11 WriteSingleReg AGCCTRLO pRfSettings gt agcctrl0 WriteSingleReg FSCAL3 pRfSettings gt fscal13 WriteSingleReg FSCAL2 pRfSettings gt fscal2 WriteSingleReg FSCAL1 pRfSettings gt fscal1 WriteSingleReg FSCALO pRfSettings gt fscal0 WriteSingleReg FSTEST pRfSettings gt fstest WriteSingleReg TEST2 pRfSettings gt test2 WriteSingleReg TEST1 pRfSettings gt test1 WriteSingleReg TESTO pRfSettings gt test0 WriteSingleRe
25. xt instruction while RF1AIFCTL1 amp RFINSTRIFG 11 Write the strobe instruction if strobe gt RF_SRES amp amp strobe lt RF_SNOP gdo_state ReadSingleReg IOCFG2 buffer IOCFG2 state WriteSingleReg IOCFG2 0x29 chip ready to GD02 RF1AINSTRB strobe if RF1AIN amp 0x04 0x04 chip at sleep mode if strobe RF_SXOFF strobe RF_SPWD strobe RF_SWOR else while RF1AIN amp 0x04 0x04 chip ready Delay for 810usec at 1 05MHz CPU clock see erratum RF1A7 __delay_cycles 850 WriteSingleReg IOCFG2 gdo_state restore IOCFG2 setting while RF1AIFCTL1 amp RFSTATIFG else chip active mode SRES RF1AINSTRB strobe statusByte RF1ASTATB return statusByte L aeaa OOOO GOO E k kk kkk kkk k kk kk kkk kk kk kkk kkk kk kk kkk kk k fn ResetRadioCore brief Reset the radio core using RF_SRES command param none return none L OOOO OOOO OOOO OOO k kk kk kkk kk I ARK void ResetRadioCore void Strobe RF_SRES Reset the Radio Core Strobe RF_SNOP Reset Radio Pointer L OOOO EEE o EE E kkk k kk kkk kk kk kk kkk kkk kk kk kkk kk k fn WriteRfSettings brief Write the minimum set of RF configuration register settings param RF_SETTINGS pRfSettings Pointer to the structure that holds the rf settings return none L aeaa aaoo EEE E EE E k kkk k kk kk kkk kk kk kkk kkk kk kk kkk kk k void Wri
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