P-REV Initial PCB

1. P-REV Initial PCB Michael Connaboy Stephen Schiffli Ram Hudiara Win Than Aung

2. Design Considerations(I) • Microcontroller Peripheral Usage • Input Interfacing • 9 ATD • 3 UART (1 for GPS,2 for left/right motor controller) • Output Interfacing • 1 USB (micro to atom board) • 2 PWM (motor controller output adjustment) • 1 UART (Xbee wireless module) • Atom Peripheral Usage • 1 USB to MIMO touch screen • 1 USB to microcontroller

3. Design Considerations(II) • Microcontroller Code • Polling loop + interrupt-driven • Using vectored interrupts for all digital inputs • Using a polling loop to grab all analog sensors’ data • Atom Code/Basestation • Polling loop

4. Hierarchical Diagram

5. Flow Chart – Main Loop • The main iterative loop • Average buffered analog data • Retrieve the GPS data and steering angle data (interrupt driven) • Calculates power ratio • Power distribution ratio to the rear wheels based off of the steering angle and the geometry of the car • Transmit the data

6. Flow Chart - Sensor Gathering • Sensor gathering routine • Interrupt driven by a timer • Captures analog sensor values and stores them into a circular buffer • Sets a flag if the buffers are full

7. Flow Chart - Traction Control • Traction Control algorithm • Looks for an RPM sensor update • RPM sensor reports a time stamp every 8 pulses • Calculates the RPM • Finds difference between desired power ratio and actual power ratio • Calculates appropriate adjustment • Scales adjustment based on throttle position • Updates the motor controller

8. Flow Chart - Calibration • Receives data from the atom via USB • This includes calibration data for throttle and break position, steering angle, and kart geometry

9. Current Status • Done • GPS • UART • Xbee • Winapplication GUI • In Progress • Researching USB communication ( bidirectional microcontroller & atom) • Main loop • Traction Control

10. Q&A • Questions?