I have made and ECM test bench, that has been useful for testing code and learning about how ECMs function.
I started with a MegaSquirt JimStim 2.0, and have made some jumper harnesses for different GM ECMs. I plan to use this to learn about other manufacturers ECMs as well.
I started with the JimStim 2.0, since it had trigger wheel simulation, for simulating engine RPM.
Here are some old pictures, I will get some new ones soon.
Anyone else use a test bench?