Wireless Data Acquisition for SAE Car Project by: J.P. Haberkorn & Jon Trainor Advised by: Mr. Steven Gutschlag

Presentation Outline Project Overview Project Overview –Functional Description Hardware Description Hardware Description –Wireless Transceivers Software Description Software Description Current Progress Current Progress Future Work Future Work

SAE Formula Car Ongoing Senior Design Project at Bradley University Ongoing Senior Design Project at Bradley University Needs a system that can track the car’s behavior in real time and record data for future analysis. Needs a system that can track the car’s behavior in real time and record data for future analysis.

Benefits of System Accurate data logging Accurate data logging Stored in Excel Spreadsheet Stored in Excel Spreadsheet Safer for car driver Safer for car driver Real time viewing Real time viewing

Wireless Data System Use the EMAC to interface with the sensors on the car. Use the EMAC to interface with the sensors on the car. Transmit the data wirelessly to a laptop computer and store it for further analysis. Transmit the data wirelessly to a laptop computer and store it for further analysis. Use the Aerocomm AC Wireless Transceivers. Use the Aerocomm AC Wireless Transceivers. Update the laptop frequently to observe and record car behavior. Update the laptop frequently to observe and record car behavior.

Data to Acquire Car Velocity Car Velocity –Acceleration Computation Engine Speed Engine Speed Engine Water Temperature Engine Water Temperature Oil Pressure Oil Pressure Suspension travel Suspension travel –Four Sensors

Functional Description

Aerocomm AC MHz Transceivers 900 MHz Transceivers Range of about 1 mile. (4 miles with external antenna) Range of about 1 mile. (4 miles with external antenna)

Aerocomm AC Use RS232 Com Port 2 to communicate serially with Transceivers.

Aerocomm AC Chips must be initialized to same settings. Chips must be initialized to same settings. Use AT Command Mode to Initialize AC4790. Use AT Command Mode to Initialize AC4790. AC4790 responds back to Host when issued a command. AC4790 responds back to Host when issued a command.

Aerocomm AC Initializing the AC4790 for Data Transmission Initializing the AC4790 for Data Transmission

Aerocomm AC AT Command Example AT Command Example WriteRead

Aerocomm AC

Transmitting Data 256 Byte Buffer Set threshold on buffer for transmission initiation – –Set RF Packet Size Each hop takes 50ms

Additional Hardware One on-board EMAC Microcontroller Development Board to process sensor signals and transmit them through the RS232 Com Port 2. One on-board EMAC Microcontroller Development Board to process sensor signals and transmit them through the RS232 Com Port 2. One additional EMAC Microcontroller Development Board to test the receiving end of the system before interfacing the transceiver directly with a laptop. One additional EMAC Microcontroller Development Board to test the receiving end of the system before interfacing the transceiver directly with a laptop.

Equipment List (2) EMAC Microcontroller Development Boards (2) EMAC Microcontroller Development Boards  (2) Aerocomm AC Transceiver Chips  (2) MC1488 and MC1489 Drivers  Various Analog Components for Protection Circuitry  Function Generator  Digital Multi Meter Oscilloscope Oscilloscope Laptop Laptop  High Current Power Supply (to run wheel sensor motor)

Software Requirements Utilize A/D Converter and interrupts to interpret the signals from the SAE car. Utilize A/D Converter and interrupts to interpret the signals from the SAE car. Use Com Port 2 to interface the transceiver with the EMAC board. Use Com Port 2 to interface the transceiver with the EMAC board. Update information as required by the Mechanical Engineers. Update information as required by the Mechanical Engineers. –Different Priorities

Updating Priority Priority ONE Priority ONE –Car Velocity –Engine Speed –Suspension Travel –Lap Timer Priority TWO Priority TWO –Engine Water Temperature –Oil Pressure

Transmitting Flow Chart

Receiving Used EMAC board to receive data from the transceiver. Used EMAC board to receive data from the transceiver. Ideally, the transceiver will be directly connected to a laptop through the RS232 port. Ideally, the transceiver will be directly connected to a laptop through the RS232 port. –MATLAB can provide this functionality. –Program would store data in some usable form (i.e. Spreadsheet, notepad file) –Program would display critical information on laptop screen and update as new information is received.

Current Progress Completed task of getting two EMAC boards to communicate with each other via RS-232 ports. Completed task of getting two EMAC boards to communicate with each other via RS-232 ports. –Sine wave applied to A/D converter and transmitted out through COM2 port. –Second EMAC board receives converted signal and sends it back to the first EMAC board. –When the signal is received by the first EMAC, the transmission is sent out through the D/A converter and compared with the input signal on an oscilloscope.

Current Progress

Established serial communication with AC4790 Transceivers. Established serial communication with AC4790 Transceivers. AT Command Mode mastered. AT Command Mode mastered. Successfully initialized both transceivers. Successfully initialized both transceivers.

Current Progress Wirelessly transmitted and received data. Successfully sent and received 40 continuous bytes of data in one packet. No errors in data

Current Progress Attempted to send continuous streaming data Attempted to send continuous streaming data –100Hz Sine Wave Buffer filling up Buffer filling up –Data loss occurring

Current Progress Simulated car signals on transmitting end. Processed signals and sent out in a packet. – –Updated every 0.5s

Future Work Implement MATLAB Software to display data in real time on off-track computer. – –We already have program information Testing with actual car sensors Design and build casing for inside the SAE Formula Car – –Install hardware on formula car

Questions?