Direction controller
The direction controller is a small PCB used as a driver interface to select drive direction. It does not contain any logic, just enough to make 3 buttons and 3 LEDs available to the driver:
- Forward
- Neutral
- Reverse
The button state is communicated to the VCM which control the state of the LEDs.
Hardware
The hardware is crated using KiCad and can be found in in the vehicle controller GitHub repository
PCB
TBD
Connectors
The direction controller has four 4-pin JST-PH connectors
- Connector housing: JST PHR-4
- Crimp contact: JST SPH-002T-P0.5S
Main connector
| Pin | Function |
|---|---|
| 1 | CAN High |
| 2 | CAN Low |
| 3 | +12 V (Ignition) |
| 4 | GND |
3 x Button connectors
Thee button connector has the same pinout for:
- Forward button
- Neutral button
- Reverse button
| Pin | Function |
|---|---|
| 1 | LED Anode |
| 2 | LED Cathode |
| 3 | Button |
| 4 | Button |
The current limiting resistors on the PCB is adapted to provide ~10 mA to the following LED forward voltages. If any other LEDs are used, the resistors R?, R? and R? may need to be replaced with other values.
- Forward: 2.8 V (blue)
- Neutral: 3.5 V (white)
- Forward: 2.8 V (blue)
Firmware
The firmware for the STM32G431CB is written in rust using Embassy and is very simple. It listens to the TBD frame from TBD CAN containing state for the LEDs and response with a frame containing the state of the pushbuttons.
The firmware can also be found in the vehicle controller GitHub repository