The TouCAN-Pi is one of a range of Dual CAN boards currently in development. The dual transceiver allows the following features:
- CAN bus interrogation / message injection
- Bus splitting / node isolation
- Joining of buses
The TouCAN-Pi variant is designed specifically for the Raspberry Pi Zero W. Supporting software allows communication over Bluetooth or WiFi. The board supplies 5V power to the Pi from the vehicle, (through an onboard regulator), and receives 3.3V from the Pi for the two MCP25625 CAN Controller/Transceiver chips. Bus termination of 120ohms can be disabled via on board DIP switches, and bus power can be passed between buses/nodes or isolated via an onboard switch.
The supporting software comprising of a Python program and libraries for the Raspberry Pi and a JavaFX analysis tool for a laptop or PC will be available on Github. A 3D printed case will also be available on Thingiverse.
Note: The power regulation is suitable for nominal 12V or 24V vehicle supplied power, but there is no over or under voltage protection, nor is there any protection against power being fed back from the Raspberry Pi should it be connected to a USB supply. The intention is that it is powered from the vehicle and communication is wireless negating the need for a USB connection or power to the Pi.