After getting familiar with CAN bus usage in my MX-5, I decided to build a universal module, based on $10 Raspberry Pi Zero W microcomputer.

My first project will be to integrate the front and rearview cameras, adding guiding moving lines. In order to do this, I need to intercept CAN bus communication with CMU and manipulate with CAN traffic to make the main display available when the car moves forward with a speed limit of 5-7 mph.

For video switching between front and rear cameras, I decided to use NTSC to CSI-2 convertor.  I can manipulate with video images on the Raspberry Pi processor, to overlay computer-generated images; to make adjustable guiding lines, controlled by steering wheel angle. Raspberry Pi has NTSC output, which can be connected to rearview camera input on CMU.

Here is a block diagram of my board:

This device can be used as a “black box” recorder, or as an OBD2 Wi-Fi adapter, with a simple way to install any custom application, designed on the Raspberry Pi platform.

I have a few extra boards available. If you’re interested in designing your own application, use this form to contact me.