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Design Constraint Analysis

1. Rabbit Semiconductor Softec Microsystems N A Packaging Core Module Board Core Module Board 112 Pin LQFP SRAM 512K Program 512K data 8K 8K Flash 512K 64K 64K Extended Memory 4 Mbyte Serial Flash single chip 8 Mbyte Serial Flash 1 Mbyte x 8 None General Purpose I O 49 Up to 70 Up to 70 Serial Interfaces 5 total with 5 configurable as SCI 3 as SPI 2 SCI 1 SPI 1 PC 2 SCI 1 SPI 1 PC Real Time Clock Yes No No SRAM Battery Backup Yes No No Timers Ten 8 bit and one 10 bit Ten 8 bit and four 16 bit Ten 8 bit and four 16 bit Pulse Width Modulators 10 bit free running counter and 4 PW registers None None Analog to Digital No Yes Yes Quadrature Decoder Yes No No Ethernet 10 100 10 100 10 100 Power 3 15 3 45V DC 275 mA 3 3V 3 3V 3 3V Cost 99 600 120 each Minimum Qty 5 8 25 for components Figure 3 0 1 Feature Comparison of Microcontroller Modules LCD Selection Figure 3 0 2 shows a feature breakdown of three LCD modules from ezLCD Apollo Displays and Crystalfontz The ezLCD module contains a Sony 2 7 240x160 pixel active matrix TFT screen The Apollo Displays module contains an Optex 5 7 240x64 pixel STN transmissive screen Finally the Crystalfontz module is based off of their 320x240 STN transmissive screen 6 7 LCD screens is a place where bigger is not always better As you can see from figure 3 0 2 both the Optrex and Crystalfontz screen are significantly larger than the Sony screen in terms of both
2. cm 15 4cm 10 cm Transponder Samples Yes Yes Yes Software Yes No Yes Cables Yes Yes Yes Cost 284 76 95 625 350 for students Figure 3 0 3 Feature Comparison of RFID Readers 4 0 Summary The DRINK system design constraints and component selection rationale have allowed us to select the Rabbit RCM3315 as our microprocessor the ezLCD 001 as our graphical LCD and the RI K3A 001A Low Frequency Micro RFID Kit as our RFID solution These components were selected based off of their appropriateness for our application based off computational capabilities hardware interfacing considerations packaging needs and electrical characteristics ECE 477 Digital Systems Senior Design Project Spring 2006 List of References 1 EarthLCD 2005 ezLCD 001 Data Sheet Available http www earthcomputer com public_html downloads ezLCD 001_DataSheet pdf Feburary 10 2005 Data accessed 2 Digi Key 2005 Volume pricing information Available http www digikey com Feburary 10 2005 Date accessed 3 Rabbit Semiconductor 2005 RCM User Manual Available http www rabbitsemiconductor com products rcm3305 Feburary 10 2005 Date accessed 4 Softecmicro 2005 CM HCS12NE64 Product Brief Available http www softecmicro com downloads doc cm hcs12ne64_brief pdf Feburary 10 2005 Date accessed 5 Freescale Semiconductor 2005 MC9S12NE64 Product Summary Available http www freescale com webapp s
3. diagonal screen size and total screen area The Crystalfontz screen even has more pixels than the Sony screen But after examining the contrast ratio and response times of both the Crystalfontz and Optrex LCD screens we can see that they are both dismal compared to the Sony The Sony LCD s response time is over twenty times faster and the contrast ratio is over twice that of the alternatives The result is that the Sony is much more viewable and capable of refreshing the screen much faster 8 9 But perhaps the most important aspect of our LCD component selection is the interfacing and control options available on each module The Crystalfontz module only allows parallel communications with no high level control functions or additional features The Apollo Displays module is significantly more advanced with both serial and parallel along with the capability to plot lines from X Y coordinates draw circles and upload bitmaps The ezLCD display is the most advanced of the three with a whole variety of interfacing options including parallel serial USB and VC It allows shape and graphics drawing functions ECE 477 Digital Systems Senior Design Project Spring 2006 that are similar to the Apollo Displays module but its control feature that places it firmly above the rest is the ability to flash the firmware of the device with your own fonts and bitmaps This means you can almost instantly recall frequently used icons and bitmaps without having t
4. ECE 477 Digital Systems Senior Design Project Spring 2006 Homework 3 Design Constraint Analysis and Component Selection Rationale Due Friday February 10 at NOON Team Code Name Digital Real time Intelligent Networked Kegerator Team Member Completing This Homework Ian Snyder Group No 4 Evaluation Component Criterion Score Multiplier Points Introduction 0123456789 10 xX 1 Analysis of Design Constraints 0123456789 10 X3 Rationale for Component Selection 012345678910 X3 List of Major Components 012345678910 XI List of References 012345678910 X1 Technical Writing Style 012345678910 X1 TOTAL Comments ECE 477 Digital Systems Senior Design Project Spring 2006 1 0 Introduction The Digital Real time Intelligent Networked Kegerator is a modular addition to any existing beverage dispensing device With the DRINK system the owner is able to control monitor and record draft beverages on a per user basis through a web interface Users are able to view various consumption statistics and other information through a graphical LCD interface and pushbutton RPG The system authenticates users by using a short range low frequency RFID located on the bottom of their cup and a PIN entered via the system s pushbutton RPG 2 0 Design Constraint Analysis This report outlines the software hardware product packaging and cost requirements of our design Computational require
5. e lines are locked out and the solenoids are on the bill acceptor will be shut down via software This will save 3A of current at 12V and insure that we do not approach our DC power supply s maximum current rating of 8 3A Total Current Requirements mA 3 3V 375 5V 462 12V 7960 12V Supply Current 8349 Figure 2 5 2 System Current Requirements Worst Case 2 6 Packaging Constraints This device needs to be designed in a modular fashion to allow easy installation and expandability Installation constraints require that the entire module consisting of the PCB LCD bill acceptor and RPG bolt directly to the top of any standard freezer The power supply will be placed in the bottom of the freezer and plug into the top unit Solenoids flow meters temperature probes and all additional hardware must have consolidated wiring that minimizes the amount of plugs to the top unit All electronics need to be sealed from the outside world to guard from potential spills The top unit must have a locking door for bill retrieval 2 7 Cost Constraints Due to the fact that our product is designed for the high end consumer and commercial applications we have set our prototype budget goal to 1000 Primary reasons for our project s high cost include the need for support on two beverage lines rather than one our RFID reader s evaluation kit our high quality graphical LCD LCD controller and our storage abundant microcontroller module We feel comf
6. e devices in our design call for the same operating voltage Table 2 5 1 summarizes the individual device voltage and maximum current requirements Our device will have a 12V DC power supply that is capable of providing 8 3A of current This power supply will tap into the freezer s AC power line from the inside of our refrigeration device near the compressor This area must be able to dissipate heat efficiently enough to keep the compressor temperature below 65 degrees C its operating maximum This temperature will be monitored by the microcontroller Fans on the existing vents may be required if the temperature is increased due to the heat dissipated by the DC power supply Be ECE 477 Digital Systems Senior Design Project Spring 2006 Part Voltage V Max Current mA Quantity Total Current mA ezLCD 001 Display Module 3 3 100 1 100 Rabbit RCM3315 3 3 273 1 273 RS 232 Transceiver 3 3 1 2 2 Vision 2000 Flowmeter 5 80 4 320 TI S2000 Microreader 5 100 1 100 Grayhill RPG 5 30 1 30 Maxim Digital Thermometer 5 4 3 12 Solenoid Valve 12 1200 4 4800 ICT Bill Acceptor 12 3000 1 3000 Omicron SPST NO Contactor 12 160 1 160 Figure 2 5 1 Individual Component Current Requirements Figure 2 5 2 shows the total current requirements by voltage along with the total current required from our 12V power source assuming 90 efficient onboard DC to DC transfer of 12V to 3 3 and 5V Due to the high maximum current requirement in the scenario where all beverag
7. ed 14 Texas Instruments 2005 S2000 Low Frequency RFID Reader Datasheet Available http www ti com rfid docs manuals pdfSpecs RI STU MRD1 pdf Feburary 10 2005 Date accessed ECE 477 Digital Systems Senior Design Project Spring 2006 Appendix A Parts List Spreadsheet Vendor Manufacturer Part No Description Unit Cost Qty Total Cost EarthLCD ezLCD ezLCD 001 ezLCD 001 Intelligent Display Module 150 1 150 N A Remag AG Vision2000 4F23 3 8 Inline Flow meter 25 3 75 00 Newark Omron 89C758 30A Contactor Normally Open 19 66 1 19 66 Texas Instruments Texas Instruments RI K3A 001A Texas Instruments S2000 Micro RFID 284 29 1 284 29 Digi Key Maxim DS18S20 Maxim IC THERM MICROLAN HI 5 04 4 20 16 PREC TO 92 McMaster Carr Delrin 7876K24 Delrin Solenoid Valve Normally Open 56 15 2 112 30 3 8 NPT thread with quick disconnects N A Rabbit Semicond RCM3315 Rabbit 3315 Microcontroller 99 1 99 Newark Grayhill 62S 11 M5 050C Grayhill Series 62S Optical Encoder 37 81 1 37 81 Newark XP AED100US12 12V 8 3A DC Power Supply 88 1 88 Newark N A MC18S 2D Aluminum Knob with Indicator Line 2 26 1 2 26 Lowes Various N A Tubing and Hardware 30 1 30 Newark N A N A Optocouplers 0 50 8 4 ICT ICT A623 SOR US4 ICT Bill Acceptor donated 0 1 0 TOTAL 922 48 10 ECE 477 Digital Systems Sen
8. een as a user operates the device Depending on the screen type the transmission of graphic data from the microprocessor to LCD controller can be a significant resource requirement For example assuming that we have a color screen using an 8 bit color depth drawing a bitmap would require at least the start x y position of the picture picture dimension information and a byte for the color of each pixel 1 Refreshing a screen in this manner would quickly saturate a serial communications interface even at 115 2k baud Depending on the size of the screen it is possible that one could only refresh a fraction of the screen at one frame per second In order to support fast screen redraws our LCD controller must be advanced enough to allow either an SPI interface from the microcontroller or provide onboard flash or SRAM to offload some of the bandwidth requirements Advanced LCD controller functions that allow capabilities such as the ability to draw lines from point to point are also favorable ECE 477 Digital Systems Senior Design Project Spring 2006 The microprocessor must have enough processing capability left after all of these tasks to host the administrator s webpage Commands sent from the administrator via the web interface must update the system in real time 2 2 Interface Requirements General I O pins will be needed for each of the flow meters and solenoids Each beverage line will require one flow meter and one solenoid Since we wo
9. ing Quantity Produced and Number of Beverage Lines 3 0 Component Selection Rationale Microprocessor Selection Figure 3 0 1 shows a feature breakdown between two core module boards based off the Rabbit 3000 and Freescale HCS12NE64 microprocessors and the individual HCS12NE64 The RCM3315 is a Rabbit 3000 module featuring 512K of SRAM flash and program memory Five serial ports provide extensive interfacing capabilities The CM HCS 12NE64 is a core module produced by Softec Microsystems which offers significantly less on chip memory and serial interfacing resources This module only offers 8K of SRAM 64K of flash memory and three serial ports Both modules feature extended flash memory through an on module serial interface and Ethernet capability The Rabbit product has 4 Mbytes while the Softec module has 8 Mbytes of additional storage The individual HCS12NE64 does not include extended flash memory but is capable of supporting it with an external boot loader much like the hardware on both core modules 3 4 5 We have selected the RCM3315 as our microprocessor of choice The large battery backed SRAM will allow us to store comprehensive user and system statistics without having to parse through a large pour log stored in flash to update calculations Additionally the large SRAM will allow us to avoid 100 000 write cycle limitation of flash because we will be updating our flash infrequently In the event of power loss the SRAM data will be p
10. ior Design Project Spring 2006 11
11. is approximately four centimeters While this could work we believe that a larger detection range would be more appropriate for our application The antenna is non removable and the interfacing is only offered through USB 12 That leaves us with the two Texas Instruments kits Both have comparable read ranges of at least 10 cm Both come with everything you need to get setup and running The only real difference in reading capability is the RX MFR RNLK s ability to read both high and low frequency transponders As far as packaging the RI K3A 001A comes with a DIP packaged reader that would be easy to solder into our PCB The RX MFR RNLK comes with a small PCB module that would have to be screwed down to our board 13 14 We have decided to go with the RI K3A 001 based on its adequacy for our application since we do not believe we need high frequency capability The price point on this reader is more attractive even after receiving a student discount on the RX MFR RNLK ECE 477 Digital Systems Senior Design Project Spring 2006 Device Model RI K3A 001A Low Frequency Micro RFID Kit Phidget USB RFID Kit RX MFR RNLK Module Manufacturer Texas Instruments Phidget USA Texas Instruments Module Package 32 pin DIP PCB PCB Frequency 134 2 kHz 125 kHz 134 2 kHz 13 56 Mhz Antenna 80mm Disk 63mm Onboard Coil LF HF Antennas Replaceable Antenna Yes No Yes Interface Board RS232 IF Port Power and Antenna Connectors USB RS 232 RS 485 Typical Read Range
12. ments and limitations are discussed followed by requirements for hardware interfacing between the system components and microcontroller peripherals Maximum current requirements and heat dissipation are presented along with packaging and cost limitations This report also details our rationale for selecting our microcontroller LCD screen and RFID reader 2 1 Computation Requirements During operation the kegerator will be responsible for logging pours and calculating user statistics All pour logging will be stored into flash memory with a time stamp Many common calculations using this data will require a significant amount of unit conversion and averaging of data over multiple time periods Some example calculations include predicting when a keg will expire under current average consumption rates creating data points for the plotting of a user s blood alcohol level and converting statistics from the metric system to the English standard system This information will be constantly calculated and updated for all users in the system Interrupts from flow meters must be counted as they are triggered Each flow meter I O line can potentially send one hundred pulses per second to the microprocessor Temperature readings will need to be polled at various intervals and inputs from the user interface s control knob and pushbutton will trigger changes in the system The kegerator s user interface will be able to redraw portions the graphical LCD scr
13. o send serial data from the microprocessor The end result is a more interesting and interface user interface The ezLCD 001 is our LCD of choice Device Model ezLCD 001 F 51851GNFQJ LY AND CFAG320240C FMI T Module Manufacturer ezLCD Apollo Displays Crystalfontz Screen Manufacturer Sony Optrex Crystalfontz Screen Technology Active Matrix TFT STN Transmissive STN Transmissive Color Yes No No Resolution pixels 240x160 240x64 320x240 Diagonal Size 2 7 5 7 5 7 Viewable Area cm 37 03 48 96 110 4 Contrast Ratio 13 to 1 6 to 1 3to1 Response Time ms 15 310 350 Controller ezLCD 001 CDS 51405 1D3305 Controller Flash 94k None None Interface Serial USB I C Parallel Serial Parallel Parallel High level control functions Yes Yes No Evaluation Board Yes No No Samples Available Yes Cannot get controller Yes Cost 200 150 for students 171 142 73 Figure 3 0 2 Feature Comparison of Graphical LCD Modules RFID Selection Figure 3 0 3 shows a feature comparison of three RFID evaluation kits Unfortunately the market s current selection of low cost RFID reader modules is very limited We were able to limit the possible choices to two Texas Instruments RFID evaluation kits and a kit offered by Phidget USA All of the kits operate at low frequencies with the exception of the RX MFR RNLK kit which read both low and high frequency transponders 10 11 While the Phidget USA module is by far the cheapest solution the read range
14. ortable with this prototype s cost due amount of added value and functionality that it will be able to contribute to users and the fact that crude commercial versions of our system retail for prices upwards of 4000 Figure 2 7 1 shows estimated costs of various single build systems and various mass produced Qty 1000 systems The cost to produce a second unit with one beverage line is 738 but if that unit is produced in a quantity of 1000 the production cost would only be 404 On ae ECE 477 Digital Systems Senior Design Project Spring 2006 the other side of the spectrum a mass produced commercial system with 32 beverage lines could be produced for 2 125 95 A system of this size could commercially sell for tens of thousands of dollars This chart does not include packaging costs 2 Part Prototype Qty1 Qty 1000 Microcontroller 99 99 69 Graphical LCD Display Controller 150 200 00 100 00 Temp Sensors 3x 15 12 15 12 6 84 Optical Encoder Switch 36 99 36 99 22 20 Flow meters each 25 40 26 Solenoids each 56 15 56 15 30 Bill Acceptor Free 200 00 100 RFID 284 71 48 40 Contactor 19 66 19 66 10 Total Cost for 1 Beverage N A 738 404 Total Cost for 2 Beverage 767 07 815 39 451 35 Total Cost for 8 Beverage N A 1 411 45 792 52 Total Cost for 32 Beverages N A 3 719 05 2 125 96 Note Prototype costs reflect student discounts Select Qty 1000 prices are estimated Figure 2 7 1 Cost Breakdown Vary
15. ps site prod_summary jsp code MC9S 12NE64 amp srch 1 Feburary 10 2005 Date accessed 6 Apollo Displays 2005 Available http www apollodisplays com pdf OPA stepprod pdf Feburary 10 2005 Date accessed 7 Crystalfontz 2005 CFAG320240CFMIT Data Sheet Available http www crystalfontz com products 320240c CFAG320240CFEMIT pdf Feburary 10 2005 Date accessed 8 Optrex 2005 51553 Product Information Available http www optrex com pdf 5 1553 pdf Feburary 10 2005 Date accessed 9 EarthLCD 2005 Sony ACX705AKN 7 Product Datasheet Available http www earthlcd com downloads acx705akm 7 pdf Feburary 10 2005 Date accessed 10 Texas Instruments 2005 S4100 Multi Function RFID Evaluation Kit Available http www ti com rfid docs manuals pdfS pecs RF MFR RNLK 00 pdf Feburary 10 2005 Date accessed 11 Texas Instruments 2005 S2000 Low Frequency RFID Micro Evaluation Kit Available http www ti com rfid docs manuals pdfS pecs RI K3A 001Apb pdf Feburary 10 2005 Date accessed ECE 477 Digital Systems Senior Design Project Spring 2006 12 Phidgets 2005 RFID Reader Product Datasheet Available http www phidgets com documentation 1023 pdf Feburary 10 2005 Date accessed 13 Texas Instruments 2005 S4100 Multi Function RFID Reader Datasheet Available http www ti com rfid docs manuals refmanuals rf mgr mnmn_ds pdf Feburary 10 2005 Date access
16. reserved due to the battery backup The HCS12NE64 based solutions do not offer us this flexibility The Softec module s 4 MByte flash memory lead over the Rabbit does not offer a significant advantage as 4 MBytes is already enough memory to store hundreds of thousands of time stamped pour database entries customizable user icons pictures and a robust web interface Using the additional 4 Mbytes for more complex LCD graphics is not practical due to our 4 ECE 477 Digital Systems Senior Design Project Spring 2006 115200 baud communication limitation It is simply not possible to refresh the screen fast enough with large bitmaps being sent from flash to the LCD Finally the RCM3315 decision was strengthened due to the availability of a 3300 series Rabbit development board and the large cost of acquiring a Softec module The lab staff was able to provide the 3300 series Rabbit development board free of charge The cost to purchase the AK S12NE64 A development kit from Softec is 450 Also Softec has a minimum order quantity of five units for their CM HCS12NE64 modules The cost for the Rabbit was only 99 The individual HCS12NE64 is only 8 but requires at least 25 in additional components to achieve the same functionality as the Softec module Due to availability issues for the supporting components and added complexity of implementation we have ended our pursuit of this option Device Model Wk CM HCS12NE64 HCS12NE64 Module Manufacturer
17. uld like to support up to four beverage lines with our design 8 general I O lines will be required Two additional I O pins will be needed for our temperature probe network and contactor Some of the remaining I O pins will be used to interface to a PLD to allow future beverage line expandability All I O pins will accept 5V All off board inputs must be optically isolated to help reduce noise and prevent damage from ESD This means all flow meters solenoids and PLD pins will need optocouplers 2 3 On Chip Peripheral Requirements An embedded web server with an Ethernet connection to the internet will be at the heart of our system Additionally three serial communications interface ports will be needed for an RFID reader graphical LCD display and bill acceptor A single quadrature input will be required to interpret signals from the optical encoder knob that will provide our human machine interface Multiple timer channels will be essential for tracking the time between system events 2 4 Off Chip Peripheral Requirements Data stored in SRAM will need to be backed up by a battery to prevent data loss in the event that the system loses main power An LCD controller will be required to accept serial communication from our microcontroller and drive the LCD to create text and graphics RS 232 transceiver chips will need to be used to communicate with serial devices if our microcontroller lacks of transceivers 2 5 Power Constraints Not all of th

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