Formula SAE Ryan Langley 2104584 GPS & Sensor Telemetry HPV Sensor Suite Thomas Cross 2107294 Formula SAE Ryan Langley 2104584

HPV Super Series Human Powered Vehicle Multiple riders per vehicle Endurance races Manual lap timing

Project Aims Sensor suite onboard vehicle Location, speed and lap times Data logging Display data to pit crew

Vehicle Module GPS + Accelerometer Speed display Data logging Data communications Pit Module Graphical User Interface View real-time data Log/display lap times Data communications

Hardware Firmware GUI

Hardware Firmware GUI

Reverse Polarity & Overvoltage Protection Input Power Reverse Polarity & Overvoltage Protection Switched-Mode Power Supply (5V) Linear Regulator (3.3V) GPS Module Accelerometer UART I2C Microcontroller Microcontroller UART I2C SPI RF Module Liquid Crystal Display SD Card

Reverse Polarity & Overvoltage Protection Input Power Reverse Polarity & Overvoltage Protection Switched-Mode Power Supply (5V) Linear Regulator (3.3V) GPS Module Accelerometer UART I2C Microcontroller Microcontroller UART I2C SPI RF Module Liquid Crystal Display SD Card

Circuit Protection Reverse polarity protection Overvoltage protection Transient suppression

Reverse Polarity & Overvoltage Protection Input Power Reverse Polarity & Overvoltage Protection Switched-Mode Power Supply (5V) Linear Regulator (3.3V) GPS Module Accelerometer UART I2C Microcontroller Microcontroller UART I2C SPI RF Module Liquid Crystal Display SD Card

Power Supply 3.3V and 5V rails Linear regulator for each rail 5V SMPS powering 3.3V linear regulator SMPS for each rail 3.3V @ 0.1A 5V @ 0.9A   Ploss (W) Efficiency Cost($AU) 2 x Linear 7.17 40.3% $3.30 1 x SMPS 1 x Linear 1.42 77.3% $9.41 2 x SMPS 1.21 80% $15.52

Reverse Polarity & Overvoltage Protection Input Power Reverse Polarity & Overvoltage Protection Switched-Mode Power Supply (5V) Linear Regulator (3.3V) GPS Module Accelerometer UART I2C Microcontroller Microcontroller UART I2C SPI RF Module Liquid Crystal Display SD Card

Inputs GPS Module Accelerometer Updates at 10Hz UART - NMEA Data and checksum 2.5m location accuracy Accelerometer MMA8451Q 3-Axis I2C

Reverse Polarity & Overvoltage Protection Input Power Reverse Polarity & Overvoltage Protection Switched-Mode Power Supply (5V) Linear Regulator (3.3V) GPS Module Accelerometer UART I2C Microcontroller Microcontroller UART I2C SPI RF Module Liquid Crystal Display SD Card

Outputs LCD SD Card RF Module - RFD900 UART 40km LOS I2C Displays data to rider SD Card SPI microSD

Reverse Polarity & Overvoltage Protection Input Power Reverse Polarity & Overvoltage Protection Switched-Mode Power Supply (5V) Linear Regulator (3.3V) GPS Module Accelerometer UART I2C Microcontroller Microcontroller UART I2C SPI RF Module Liquid Crystal Display SD Card

Microcontroller 2 x UART - GPS & RF Module 1 x SPI - SD Card (SPI Mode) 1 x I2C - Accelerometer, LCD PIC18F46K22 2 x UART, 2 x SPI/I2C 64KB Program Memory 64MHz oscillator

Protection Circuitry 5V SMPS GPS Programming Header 3.3V Linear Regulator Accelerometer SD Card

Hardware Firmware GUI

Hardware Firmware GUI

Formula SAE Design & build race car Students of all disciplines Annual competition Flinders’ first year

GPS Telemetry Project Basis for sensor addition Build car and driver feedback Improve performance of team

Firmware Goals Configure sensors Read in, send and process data Log data Handle errors All in real time – or close to

GPS Configure UART peripheral Configure GPS module Receive NMEA data Process & Send data

Configure UART 1 start – 8 data – 1 stop – no parity 115,200 baud Interrupt based Ring buffer TAIL HEAD $ G P R M C

Configure UART

GPS Configure UART peripheral Configure GPS module Receive NMEA data Process & Send data

Configure GPS Module Send only GPRMC and GPGSA Lat & long Date & time Speed, heading Precision Configure baud to 115,200 Send data at 10 Hz

GPS Configure UART peripheral Configure GPS module Receive NMEA data Process & Send data

Receive NMEA Data $ \n GPS_msg_flag Receive ISR N N Y Y RXIF Framing error? Buffer overflow? ‘$’ or ‘\n’ Put in buffer Exit Flush buffer Receive ISR N N Y Y $ GPS_msg_flag \n

GPS Configure UART peripheral Configure GPS module Receive NMEA data Process & Send data

Process & Send Data Pull msg from RX buffer N Y Y N $ G P R M C … \n Pull char from buffer Is it ‘$’ Place in array Is it ‘\n’ Place 0 in array Check Checksum N Y Y N $ G P R M C … \n

Accelerometer Configure I2C peripheral Configure Accelerometer module Obtain data

Configure I2C 400 kHz speed Set as Master device Generic code

Accelerometer Configure I2C peripheral Configure Accelerometer module Obtain data

Configure Accelerometer Read latest data (not FIFO) 8G, 4G, or 2G mode 8-bit resolution

Accelerometer Configure I2C peripheral Configure Accelerometer module Obtain data

Obtain data Read the values at 10 Hz Use ‘get’ functions to access X, Y, and Z values.

The Main Loop

The Results

The Results ACC IN RFD OUT GPS IN

Data Logging Easy to use Windows compatible file system Different files for GPS and ACC data

Data Logging Main Loop SD_Card.h SD_Card.c FatFs Files diskio.h diskio.c SPI.h SPI.c

Main Loop SD_Card.h SD_Card.c FatFs Files diskio.h diskio.c SPI.h SPI.c

SD Card Provides high-level logging functions Create/open files Log ACC data Log GPS data Save files

Main Loop SD_Card.h SD_Card.c FatFs Files diskio.h diskio.c SPI.h SPI.c

FatFs Generic FAT File System Module Designed for embedded systems 3rd party open source Platform independent

Main Loop SD_Card.h SD_Card.c FatFs Files diskio.h diskio.c SPI.h SPI.c

Disk IO Provides low-level disk IO functions Initialize Read Write Disk Status

Main Loop SD_Card.h SD_Card.c FatFs Files diskio.h diskio.c SPI.h SPI.c

SPI Portable SPI peripheral code Various initialization options Byte transmit, receive and exchange

Logging Result

Hardware Firmware GUI

Hardware Firmware GUI

10 Hz New Message Received? No Update Lap/Race Timer Yes No Valid Message Header? Get Message Type Plot GPS Location Display Acceleration Yes Reset No Valid Message? Lap Detected? Yes Yes Extract Message Data Log Lap Time

Receiving Data Scan until new message is received Check for valid header e.g. “$GPRMC…” Check for correct length and checksum Extract message data Lat & long Date & time Speed, heading

Update GUI Update lap/race counter every 0.1s Plot most recent GPS location Display accelerometer data Display heading/speed

Lap Detection Check if travel line crosses finish line Log lap time and display on graph/table Reset lap timer

GUI

Summary Designed generic hardware Data processing and transmission Display real-time data on user interface Autonomously log lap times