Wavecom GR64 UART Sleep Protocols Especificações

Low CostPenguin RFID Readerwith GSM UplinkbyJason Ryan ManleySubmitted to the Department of Electrical Engineeringin partial fulfillment of the require

LIST OF FIGURES7.1 Block diagram of uplink module’s hardware interconnect . . . 687.2 I2C master to slave multi-byte data exchange . . . . . . . . . 7

7.5. RELIABILITYThe presence and status of the power supply is also checked. If the batteryis low and there is no mains power supply, the peripherals

7.6. CONCLUSIONS AND POSSIBLE IMPROVEMENTS7.6 Conclusions and Possible ImprovementsThe uplink module performs as expected, meeting all device s pecific

Chapter 8Power Supply8.1 IntroductionBattery backup is required because of the poor reliability of the main powersupply on the island. Furthermore, if

8.3. REGULATOR SELECTIONDevice Voltage Ave Current Ave PowerGSM Module 3.8V 0.2% × 850mAa1.7mWMicroprocessor 5.0V 12mAb60mWLEDs 5.0V 1mAc5mWLCD displa

8.3. REGULATOR SELECTIONDevice Voltage Ave Current Ave PowerRFID Co-ordinator 5.0V 50mAa250mWMicroprocessors & misc Logic 5.0V 2×50mAb500mWOutput

8.3. REGULATOR SELECTION8.3.2 ST Microelectronics’s L4976ST Microelectronics’s L4976 devices operate at frequencies up to 300kHzand are capable of del

8.3. REGULATOR SELECTIONFigure 8.1: DC rail output of SMPS.• Adjustment in the size of the inductor - decrease from 260µH to 80µHto suit the new highe

8.4. BATTERY SELECTION AND CHARGINGFigure 8.2: Circuit diagram of switching DC-DC converterfor the GSM module (3.8V).8.4 Battery Selection and Chargin

8.4. BATTERY SELECTION AND CHARGINGdetermined based on the open circuit (or very light load) potential difference.This relationship is not linear, howe

8.4. BATTERY SELECTION AND CHARGINGThe charging of SLA batteries is well-understood and relatively simple:the battery should be charged with a constan

List of Tables5.1 Active vs Passive Tags . . . . . . . . . . . . . . . . . . . . . . 255.2 ISO 11784 64bit Transponder ID data fields. . . . . . . . .

8.4. BATTERY SELECTION AND CHARGINGconsidered is paralleling two or more such batteries to further boost backuptime. Refer to Section 8.5 for power co

8.4. BATTERY SELECTION AND CHARGINGconnected to PortA.RA4 on the GSM Logger’s Microprocessor. This is anopen collector output with FET output. It is t

8.4. BATTERY SELECTION AND CHARGINGFigure 8.6: finite state machine of charging algorithm.99

8.5. MEASUREMENTS8.5 Measurements8.5.1 Power Supply EfficiencyThe total efficiency of the converters is measured to be approximately 85%when the GSM modul

8.6. CONCLUSIONFigure 8.7: Discharge periods vs. discharge ratesat various temperatures for a Panasonic LC-R127R2P 12V 7.2Ah SLAbattery. Diagram from

Chapter 9Enclosure Selection andMounting MethodsThis chapter will discuss the recommended methods for mounting the RFIDantennae and housing the system

9.2. RECOMMENDATIONS9.2 RecommendationsBased on the aforementioned considerations, and the device specification asoutlined in Section 3, the following

9.2. RECOMMENDATIONS• The antennae windings can be sealed in epoxy to prevent corrosionof the copper wire. Careful attention must be paid to the conne

Chapter 10South African RegulationsThe Telecommunications Act of 1996 stipulates “regulations in respect of useor possession of certain radio apparatu

10.1. GSM MODULE10.1 GSM ModuleThe GSM module used in this project is purchased fully assembled, with allradio-frequency stages and the controlling fir

GlossaryADC Analogue to Digital Converter. In the context of this project, one ofthe microprocessor’s on-board peripherals.APN Access Point Name. Requ

Chapter 11Conclusion and SystemEvaluationOver five thousand lines of code were written for the four microprocessorsemployed in the system. The prototyp

The system has an expected lifespan of three years, limited by the lead-acid battery. All other components are solid-state and, bar corrosion ormechan

Appendix AAppendix: RFID ReceiverA.1 PCB Layout of Push-pull Output Readerwith Single-channel ReceiverFigure A.1 shows a reduced circuit diagram for a

A.2. PCB LAYOUT OF SINGLE-ENDED OUTPUT READER WITHDUAL-CHANNEL RECEIVERFigure A.1: Schematic of push-pull output single channel receiver readerA-2

A.2. PCB LAYOUT OF SINGLE-ENDED OUTPUT READER WITHDUAL-CHANNEL RECEIVERFigure A.2: PCB Layout: push-pull outputwith single channel receiverA-3

A.2. PCB LAYOUT OF SINGLE-ENDED OUTPUT READER WITHDUAL-CHANNEL RECEIVERFigure A.3: PCB Layout: single-ended outputwith dual channel receiverA-4

A.2. PCB LAYOUT OF SINGLE-ENDED OUTPUT READER WITHDUAL-CHANNEL RECEIVERFigure A.4: Populated dual channel receiver boardwith no top silkscreenA-5

Appendix BAppendix: RFID Co-ordinatorB.1 Circuit DiagramFigure B.1 shows the complete circuit diagram for the RFID co-ordinator asdiscussed in Section

B.2. PCB LAYOUTFigure B.1: RFID co-ordinator circuit diagramB-2

B.2. PCB LAYOUTFigure B.2: RFID co-ordinator PCB top solder sideFigure B.3: RFID co-ordinator PCB bottom solder sideC-1

LIST OF TABLESFIFO First In, First Out. Term used to describe a buffering techniquewhereby the data which was first buffered is also the first to be repla

Appendix CAppendix: Uplink ModuleDesignC.1 EEPROM Data StorageThe data backed-up in the uplink module’s onboard E EPROM is listed intable C.1. The tab

C.2. LIST OF UPLINK COMMANDSC.2 List of Uplink CommandsAll commands are issued in the formCOMMAND “space” ARGUMENT 1 “space” ARGUMENT 2 ... “CR”.Comma

C.3. PCB DESIGNCommand Argument(s)start gsm noneset time HH:mm:ss DD/MM/YYget status noneget record record number (decimal, two digits)get all records

C.3. PCB DESIGNFigure C.1: Uplink module PCB top solder sideC-5

C.3. PCB DESIGNFigure C.2: Uplink module PCB bottom solder sideC-6

C.3. PCB DESIGNFigure C.3: Uplink module full circuit diagramC-7

C.3. PCB DESIGNFigure C.4: Uplink module populated boardC-8

Appendix DAppendix: Power SupplyThe devices shown in table D.1 were all considered for use in the system’spower supply, however, due to a lack of loca

Device Manufacturer Max Freq Max I Special FeaturesMAX5072/3 Maxim 2.2MHz 2A +1A Dual channelMAX5082/3 Maxim 250kHzMAX5088/9 Maxim 2.2MHz 2A Thin QFNL

Appendix EAppendix: SoftwareThe following software was used to complete the project design:• Microchip’s MPLAB v7.4 with C18 compiler• Eagle CAD v4.11

LIST OF TABLESused to as a temporary store for variables. It is usually volatile innature.Reader Term used to describe a device which is able to read/

References[1] Texas Instruments, Series 2000 RFM Sequence Control ReferenceManual, first ed., October 1999.[2] U. o. C. T. Avian Demography Unit, “Eart

REFERENCES[11] Various Authors, “Cyclic redundancy check,” Wikipedia, 2006.[12] A. S. Tanenbaum, Computer Networks. Prentice-Hall, 1981.[13] M. Ossman

Chapter 1IntroductionThis project discusses the design and construction of a device for logging thetimes and movements of the Robben Island penguin co

1.2. OBJECTIVES AND DELIVERABLESalong various paths on the island to better track their comings and goingson the island.1.2 Objectives and Deliverable

1.4. PROJECT BACKGROUND AND JUSTIFICATION1.4 Project Background and JustificationOnce a year (between November and December), penguins come to RobbenIs

1.5. PROJECT CHALLENGESFigure 1.2: Penguin ne st on Robben IslandWe believe that a solution can be found using RFID technology. Identificationtags are

1.5. PROJECT CHALLENGESFigure 1.3: Penguins at SANC COB showing steel identifier tags.These tags are non-electronic. Picture courtesy of Simon Katz.Rem

AbstractThis project designs and implements an electronic system for automaticallylogging the movements of penguins on Robben Island using RFID and GS

1.6. REPORT STRUCTUREEnvironmental considerations The environment where the devices willoperate is harsh; physical construction requires special atten

Chapter 2Analysis of Existing SolutionThere is already a system in place which logs the birds’ movements, however,there are problems associated with i

2.1. ANIMAL DETECTION AND IDENTIFICATIONFigure 2.1: Existing system: OverviewThe second infra-red beam is interrupted as the bird leaves the gate. Thi

2.2. POWER SUPPLYFigure 2.2: Existing system: close-up of the gateshowing the Texas Instruments Series 2000 “small” loop antenna and thetwo infra-red

2.3. DATA PROCESSING AND STORAGEFigure 2.3: Existing system: Power supply and backup system• The backup system consumes much more space than it needs

2.4. DATA DELIVERYMarkham modified this original system by replacing the desktop computerwith a microprocessor which logs the data in the its on-board

Chapter 3Device SpecificationHaving reviewed the operation of the existing solution and identified itsshortcomings, this chapter aims to produce a desig

Low cost hardware It would be advantageous to install additional deviceson the island to better track the animals’ movements. This will not bepossible

Unobtrusive The device will be installed in a national heritage site. Itshould not damage the aesthetics of the environment, nor should itintrude on t

Chapter 4Overview of Proposed Solution4.1 IntroductionThis chapter discusses the overall design methodology and illustrates theoperation of the propos

AcknowledgementsThe author would like to acknowledge contributions from the following individuals:Dr Andrew Wilkinson as supervisor, for always taking

4.2. RFID DETECTOR, IDENTIFIER AND CO-ORDINATORsections in this report where the design detail for that component maybe found. A brief overview of the

4.3. UPLINK MODULEFigure 4.2: System overview: Logical connectionsIncluding the chapters where the component design is discussed.Based on the ordering

4.4. INTERCONNECTIONSbe found in Section 7.4.4 InterconnectionsThe RFID and uplink modules will need to communicate with each other.As they will not b

Chapter 5RFID Reader DesignThe following subsections give a brief overview of RFID systems, their strengthsand weaknesses and suitability for this pro

5.1. INTRODUCTION• ROM memory, often EEPROM• Power supply (in the case of active tags);2. Receiver• Antenna• Analogue interface circuitry• Digital con

5.1. INTRODUCTIONhave short read ranges of only a few centimetres [5]. Fixed installations oftenhave higher power outputs and larger antennae with inc

5.1. INTRODUCTIONFigure 5.1: Popular Texas Instruments Series 2000 AntennasFull duplex systems do not require the tags to be charged before transmitti

5.1. INTRODUCTIONenter the reading field.Passive devices typically offer limited user-programmable data storagecapacity of less than 128 bytes, and ofte

5.1. INTRODUCTIONPassive ActiveTag power source External RF field Self-contained(battery)Memory capacity Less than 128B Over 128kBCost Low HighRange Sh

5.2. SELECTION OF THE RFID SYSTEM5.2 Selection of the RFID systemWhen selecting the RFID system for the island, it is important to consider thecost of

DeclarationThis document and all of its contents represent my own work unless otherwisestated. I acknowledge that all contributions made by others hav

5.3. TRANSPONDER DATA FORMAT AND PROTOCOLbands are detrimental to the penguins. The newwer e lectronic system alreadyin place is ISO 11784/85 complian

5.3. TRANSPONDER DATA FORMAT AND PROTOCOLIf the transponder’s capacitor has be en sufficiently charged, it immediatelybegins transmitting after detectin

5.3. TRANSPONDER DATA FORMAT AND PROTOCOLwill be able to determine that at least one penguin was within range. Theantennas and gates thus need to be c

5.4. HARDWAREError Type Errors DetectedSingle bit errors 100%Double bit errors 100%Odd-numbered errors 100%Burst errors (<16bits) 100%Burst errors

5.4. HARDWAREaccommodate the RFID readers (all other system components require 5V orless). The potential differences across the antenna terminals are e

5.4. HARDWAREFigure 5.4: Overview of proposed microprocessor-based RFID readerheat would be dissipated in the power output devices as they linearly co

5.4. HARDWAREin turn drive the MOSFET. Figure 5.5 shows a circuit diagram illustratingthe operation of the antenna driving circuitry:Figure 5.5: RFID

5.4. HARDWAREFigure 5.6: RFID antenna driver circuitry using push-pull output stageresonant circuit, tuned to 130kHz. Thereafter, the signal is again

5.4. HARDWAREstage is AC coupled to the previous one to prevent DC bias offsets frombeing amplified. Low value resistors are used to prevent noise from

5.4. HARDWAREFigure 5.7: RFID receiver circuit showing amplifier stages and tuned circuit36

Contents1 Introduction 21.1 Terms of Reference . . . . . . . . . . . . . . . . . . . . . . . . 21.2 Objectives and Deliverables . . . . . . . . . . .

5.4. HARDWAREstick antennae placed in a vertical orientation. Figure 5.9 illustrates the readfields generated by the two antenna designs in both horizo

5.4. HARDWAREFigure 5.9: Detection of penguins with various antennae.Horizontal and vertical orientations are considered.38

5.4. HARDWARESince the Series 2000 tags do not allow for the reading of multiple tagssimultaneously, both reads will fail and no penguin will be detec

5.4. HARDWAREresult in a high received voltage at the transponder. As outlined in Section5.6, the number of turns on the antenna had very little influe

5.4. HARDWAREsquare-wave edges. An on-board RS232 interface will be used to transmitthe decoded data to the RFID co-ordinator.Included in all designs

5.4. HARDWAREsamples5.Thus, a faster device, or one with more memory was required. Mr AndrewMarkham recommended Microchip’s PIC 18F series and althoug

5.4. HARDWAREchannel c annot be allowed to reset the timer upon receipt of an edge as itwould interfere with the results of the second channel), each

5.5. SOFTWAREPlease see appendix A.1 for a complete circuit diagram and PCB layoutof a push-pull output, single receiver channel interrogator (with no

5.5. SOFTWAREgeneration of these signals (since they can be muxed together to produce out-of-phase waveforms), they were reserved for receive channels

5.5. SOFTWAREPeripheral FunctionCCP1 Generate interrupt on every fourth e dgeTimer0 Implement timeout (20ms)Timer3Elapsed time between CCP interrupts(

CONTENTS5.1.2 Active versus Passive Systems . . . . . . . . . . . . . . 225.1.3 Operating Frequency . . . . . . . . . . . . . . . . . . . 245.1.4 Modu

5.5. SOFTWAREFigure 5.10: RFID receiver decode state flowchart47

5.5. SOFTWARE5.5.3 Decode StageFigure 5.10 shows a simplified flowchart of the decoding stage. Decodingbegins by looking for a start byte. The Read-Only

5.5. SOFTWAREFigure 5.11: CRC verification flowchart3. No tag detected within read rangeAll responses are sent across RS232 in plain ASCII followed by a

5.6. DESIGN EVALUATIONNo tag found.This response is also possible if the antenna becomes open loop or an internalcircuit fault exists.5.6 Design Evalu

5.6. DESIGN EVALUATIONFigure 5.12: FFT of the 134.2kHz transmitted waveform.Centre frequency of the image is 127kHz with a span of 50kHz. Notice thest

5.6. DESIGN EVALUATIONFigure 5.13: Received waveform from an RFID transponderthe claims made in the article. Maximum read range was approximately100mm

5.6. DESIGN EVALUATIONclear that in order to achieve additional range, the receiver chain must beoptimised.5.6.3 Reader Range and OptimisationWith the

5.7. CONCLUSION AND RECOMMENDATIONS5.6.4 Power ConsumptionThe push-pull RFID reader consumes 420mA (at 12.5V) when transmittingand the logic consumes

5.8. IMPROVEMENTS AND FURTHER WORKThe reader should be well shielded and the area of operation shouldnot contain switching devices in these frequency

5.8. IMPROVEMENTS AND FURTHER WORKto be connected, either in a different orientation or in another location.This has the potential to decrease system c

CONTENTS6.3 Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627 Uplink Design 637.1 Introduction . . . . . . . . . . . . . . . .

Chapter 6RFID Co-ordinatorThe co-ordinator device acts as an intermediary between the RFID readersand the uplink module. It must thus be able to commu

6.2. SOFTWAREdoes not need to be fast and an RS232 standardised communication speedof 9600bps with e ight data bits, no parity and one stop bit is use

6.2. SOFTWARE2. RFID reader3. Received data processor4. Upload data preparation6.2.1 TimersThe Timer FSM can be in one of three states: either “stoppe

6.2. SOFTWAREFigure 6.1: Global timer flowchartIn one of the two trigger states, a general purpose IO pin is pulled high totrigger the connected RFID r

6.2. SOFTWAREthe buffer and compared to entries in an array of records with the datacomponents as outlined in table 6.1.Size (bits) Name Contents8 Stat

6.3. EVALUATIONindefinitely for this animal at the second gate, a time-out is implemented.If the animal does not trigger both gates within approximatel

Chapter 7Uplink Design7.1 IntroductionHaving reviewed the system specification in Section 3, and considered theimplementation of the proposed solution

7.2. DESIGN OPTIONSGSM and GPRS network coverage. Combined with TCP/IP, such a systemoffers the ability to upload the data to any device with internet

7.2. DESIGN OPTIONSat 50c per SMS, this would result in a monthly cost of R150 per month perstation1. Also, since this data would be in raw hex format

7.2. DESIGN OPTIONSLow power Communication should consume as little energy as possible toconserve battery lif e in backup conditions.Flexible It shoul

CONTENTS8.4 Battery Selection and Charging . . . . . . . . . . . . . . . . . 948.4.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . 948.4.

7.3. HARDWARE DESIGNstandard for the bus would exist. A custom design was thus not an idealsolution.A CAN or RS485 system would require additional lin

7.3. HARDWARE DESIGNFigure 7.1: Block diagram of uplink module’s hardware interconnectto have local support for the unit as well as local stock (due t

7.3. HARDWARE DESIGNperform audio functions (such as microphone and hands-free connections)and links to peripherals such as cameras or additional SIM

7.3. HARDWARE DESIGNconsidering these attributes, it was considered it the ideal solution. Theantenna is attached to the sides of the enclosure with d

7.3. HARDWARE DESIGNReal Time Clock There should be some means of timekeeping – be thisin the form of a local real time clock or a dedicated IC to whi

7.3. HARDWARE DESIGNSimple The operator should be presented with a clear, simple interface withthe minimum number of buttons and displays.Easily under

7.3. HARDWARE DESIGN7.3.5 Peripheral Communication BusThe choice to use I2C as an interface bus to the uplink module greatlysimplifies the hardware des

7.3. HARDWARE DESIGNFigure 7.2: I2C master to slave multi-byte data exchangeDiagram based on illustration from [19]An exchange from slave to master is

7.4. SOFTWARE DESIGNthe master (the uplink module ) to a slave (any attached peripheral), followedby nine data bytes from the slave to the master. It

7.4. SOFTWARE DESIGNThe processor executes the following FSMs, where each FSM is steppedonce per main loop cycle4:1. Status display update2. Poll peri

List of Figures1.1 Penguins’ moulting season on Robben Island . . . . . . . . . . 41.2 Penguin nest on Robben Island . . . . . . . . . . . . . . . . .

7.4. SOFTWARE DESIGNconfiguration, including GSM SIM card PIN number, the address of theSMTP server, GPRS configuration and details of attached peripher

7.4. SOFTWARE DESIGNAlthough a library is provided with Microchip’s C18 compiler for controllingsuch LCD displays, we opted to write our own functions

7.4. SOFTWARE DESIGNinterrupt, thereby providing exactly one second de lay between decrements.Once the timer value has decremented down to zero, it is

7.4. SOFTWARE DESIGNfunctions. As outlined in the hardware design section (Section 7.3.5), anexchange consists of one byte transmitted to the slave fo

7.4. SOFTWARE DESIGNthe RTC’s interrupts (“timer s”). It uses an eight bit counter and thushas a maximum period of 256 seconds. Also provided is the a

7.4. SOFTWARE DESIGNof approximately 50 possible states.InitialisationOrdinarily, the GSM state is “powered down”. Any software component mayinvoke th

7.4. SOFTWARE DESIGNEmailIn order to initiate an email send, the module must have successfully attachedto the GPRS APN and obtained an IP address. Ori

7.4. SOFTWARE DESIGNwill await further instruction f rom the host application.SMSIf the application requests an SMS check, the GSM FSM extracts a list

7.5. RELIABILITY7.4.9 Command Processing and Device ConfigurationThe command interface is in the form of a terminal window across RS232, orvia a combin

7.5. RELIABILITY7.5.1 SoftwareWatchdog timer A watchdog timer resets the device should a softwareerror occur, or the program get stuck in a loop. This