ElectricToyCar

(Car 1)

ProtoV1

Code implemented with intent to test control with IR and on-board user controls of the vehicle

Encountered Issues:

• IR controls send different hex code stead FFFFFF when held in testing

ProtoV1.1

Code implemented with intent to just the rider’s controls of the vehicle (speed & driving modes)

Encountered Issues:

• Motors shaking/jittery in fwd & bwd = PWM given to motor needs to start from low value so motors have time to speed up

• Motors run smoother independently -> since they are lower speeds there is less time needed to speed up

• When Arduino is reset, M2 is given power due to unallocated states of pins = since connected to LED takes a high during reset, reallocated pin 13 to pin 7

• Multiple buttons touched should keep system idle but instead triggers one/a mix of the button’s functions

ProtoV2

Encountered Issues:

• Arduino must be off to send serial output to battery
• Battery has automatic shut off when pedal switch has not been pressed for longer than ~10 minutes
• When starting up the car, pedal switch is to be pressed first while the switch for power to the Arduino and H-Bridge (Red Switch on the back of the car) is off.
• 60kg servo does not function with the Arduino library, but works if it connects to the RC receiver
• Small servo jitters when RC is shut off
• Small detail, hidden speed control switch can be implemented as a small feature incase client wants to increase the speed of the car

(Car 2)

ProtoV1

Encountered Issues: N/A

Pedal Signal Analysis

Oscilloscope Serial Plotter

Schematics

Motors Dashboard PCB

Useful Links:

• 7A/160W L298 Motor Board (https://amzn.to/2WCc6RT)
• Tesla Club Forum (https://bit.ly/2KY1rN8)

Outline

1. Disassembled car by removing unnecessary wires in the dashboard and the pedal switch. Black serial wire should be left untouched.
2. Disconneted connectors from the motors and batteries. Used quick connects on 14 AWG wire, with a crimpping tool, to connect motor connectors to L298 Motor Board. Parallel connections are made from battery connectors to split power supply to pedal switch and to Vin of L298 Motor Board and Buck Converter.
3. Modified switch that originally controlled the speed of the car to act as an on/off switch. Added a second parallel connection at the point before the Vin of the Buck Converter and Motor Board. Refer to diagrams for parallel connections and on/off switch hookup.
4. Implemented ciruit on Arduino Shield(s) (Car 1 has two Arduino Boards, Car 2 has one). For Car 1, Buck Converter has Vout split into parallel to supply power for both Arduinos.
5. Mounted Arduino(s), Buck Converter, and L298 Motor Board in front storage compartment with M3 screws and stand-off spacers, drilled in holes through the bottom of the car for a nut to be attached on the spacers. Cut a hole for power supply wires to be routed inside the side of the car.
6. On the bottom of the car two holes were drilled for the steering linkage and servo. Servo horn and steering linkage are secured with lock nuts.