GPSCOMM Critical Design Report Taylor Hughes Andy Merritt Adrian Migacz Adam Preeo

System Layout 68HC11 LCD SPI 68HC11 RF Transceiver RS-232 GPS RF RS-232 RF Transceiver RS-232 GPS Delorme

Laptop Station Laptop Computer GPS Receiver HC11 Transceiver RF Link to Field Unit

GPS / Laptop Link DeLorme GPS receiver communicates with Serial port on Laptop. GPS data uses the Rockwell GPS Protocol. GPS data updates every second. GPS initialization procedure takes about 30 seconds if there is a clear view of the sky. Laptop Computer GPS Unit

RF / Laptop Link Data from transceiver is also in RS232 format, so it can be read in on another serial port. Data coming from transceiver to laptop contains the NMEA Protocol Data from field GPS unit. HC11 used to coordinate data between multiple field units and laptop. Laptop Computer HC11 Transceiver

Serial Connections The base station will use two serial port connections to communicate with external devices for data collection. Local GPS connection – The local GPS unit uses the Rockwell Protocol for transmitting GPS data, therefore the incoming byte- stream must be parsed to extract the Rockwell GPS data. Receiver Connection – The receiver will also be connected to the base station by a serial cable. The GPS unit located on the field unit uses the NMEA format for transmitting GPS data. So, the base unit must also be able to parse the incoming byte- stream for NMEA GPS data. The base unit will also send data to the receiver of the serial connection.

Base-Station HC11 Pseudocode HC11 initialization procedure LOOP (while not signal.STOP) { FOR(1 to Number of Field units) {Read in data from Field Unit N Send data from Field Unit N to Laptop} Receive data from Laptop FOR(1 to Number of Field units) {Prepare all data for Serial Communication Store Data in memory, indexed by field unit number Send data for Field Unit N to appropriate Transceiver} }

Laptop Station Send initialization to GPS units LOOP (while not signal.STOP) { Read in data from local GPS receiver Extract relevant data from local GPS data FOR (1 to Number of Field Units) { Read in data for GPS receiver N from HC11 Extract relevant data from GPS data N } Perform Calculations Send data to field unit over RF link Update GUI with current GPS data }

GPS Communication Demonstration

GPS Parts List U-Blox RCB-LJ GPS receiver board U-Blox ANN Active GPS Antenna Connects to RCB-LJ

GPS Schematic Data sent from GPS in NMEA TTL serial protocol Must send initialization sequence

ANN Active GPS Antenna Schematic

Transceiver Parts List Low Power Radio Solutions 2 Easy Radio 900TRS FM transceivers Easy Radio Development Kit Antenna Initialization and Interfacing board

900TRS Schematic and Timing Diagram Data transmitted serially on 914MHz Data sent/received, encoded/decoded Sent out on RS232 and into MAX233

GPS and Transceiver Interfacing GPS transmits NMEA protocol HC11 via TTL serial connection 9600 Baud HC11 interfaces with the transceiver via MAX233 serial connection Transceiver interfaces with base station via RF link 914 MHz(user programmable) 9600 Baud(user programmable)

Current GPS and Transceiver Data Flow GPS Receiver MAX233 Transceiver Data flow converted to and from TTL and RS232 GPS data converted to NMEA protocol and setup to transmit Data encoded/decoded and Tx/Rx at 914MHz. Data sent out at RS232 protocol Received data sent to memory on microcontroller Data sent and Received from base station Initial data flow for testing purposes. Final data flow will include HC11

Micro-controller Data Flow HC11 PROM SRAM EPROM Xilinx GPS Data Transceiver Data Memory Mapping Xilinx Boot Code HC11 Code Data Storage

Microcontroller Data Motorola 68HC11 MCU (52-pin PLCC) 8-bit Data Bus, 16-bit Address Bus 64k Addressing Space SCI (Serial Communications Interface) GPS and Transceiver data SPI (Serial Peripheral Interface) LCD interface

MCU Characteristics Operating Voltage Range 5.0 (V) +/- 10% Current Drain/pin25 (mA) Operating Temperature-40 to 105 (°C) Supply Voltage Range-.3 to 7 (V)

Micro-controller Components List ComponentPart NumberFunction Micro-controller UnitMotorola HC11Controls data flow ClockECS 2200BSets operating frequency of MCU – 8Mhz SRAMHM6264LP-15External Memory – Store coordinates of base station and mobile units – 8k x 8 FPGA UnitXilinx Spartan XCS10, XV1800 PROM Maps data to memory EPROMTI27C256Stores boot code - – 32k x 8

CPU

HC11 timing diagrams

External EPROM and SRAM

Memory Mapping and Layout Memory Mapping/CS for external devices AS, R/W, E pins from MCU Decoder and Logic programmed in Xilinx Project Manager Tentative Memory Layout 0H FFFFH B600H512 Bytes EEPROM B600H - B7FFH 512 Bytes Internal RAM 0000H - 01FFH Reset Vector FFFEH - FFFFH 64 Byte Register Block 1000H -103FH1000H External SRAM 2000H H2000H External EPROM 3000H-A600H 3000H Extra EPROM, interrupt vectors, I/O for external devices C000H- EFFFH C000H

Xilinx FPGA

HC11 Field Unit Pseudocode Initialize HC11 -Define addresses of external components LOOP(While not signal.STOP) { Read in GPS Data from GPS to Memory Read GPS Data from Memory and Send over RF-Link to Base Station Read LCD Data from RF-Link and store in memory Read LCD Data from Memory and send to LCD via SPI }

Power Components TTL – RS232 Voltage Converter MAX233 Converts TTL and RS232 logic Voltage Regulator 7805CT Steps 12 volts down to 5 volts Supplies all components on mobile unit

LCD 4x16 character display from Crystal fontz Serial SPI interface. This will interface with HC11 SPI requires ASCII protocol to Note: Slow LCD reaction time – update speed about 16ms = 63Hz. Clock runs at max frequency of 18 kHz Backlight takes 5V, 600mA- need separate source

LCD - SPI timing diagrams

Division of Labor Andy Merritt Adam Preeo Adrian Migacz Taylor Hughes GPS Board XX Transceiver XX Memory Mapping XX Micro Controller XX Base Station XX LCDXX

Schedule

Parts Price List LCD Screen - $75 Transceivers - $200 GPS Board - $160 Miscellaneous - $10 TOTAL - $445 Opportunity to Work in the basement of the Engineering Center - PRICELESS