Hello I have done small projects with arduino but now I am stuck at Everest. I do a lot of car mechanics and sometimes I swap engines and with the newer cars the gauges cluster work with canbus signal. I can't find a way to convert analogue signals such as speed or rpm to canbus. Thanks for your time
it all starts with sensors. need to be able to read the RPM from some source. oil pressure, not an oil switch, and so on.
get that data into some sort of microcontroller.
the interaction with the CAN bus and automotive use is common and has a large community. spend some time searching for arduino CAN bus.
I have no experiance, but the first thing that comes to mind is the CPU in the car. do you have to alter that to add the data points so your sensor can post data to it.