Old code for the simple 4d display <> RS232 <> Megasquirt attached if anyone wants to take a squiz.
Links for displays:
I am actually working away at a new version implemented slightly differently:
* More code space and RAM for more features. (Using only the display gives only 400 bytes of RAM to play with)
I always wanted to add a graph feature, so if you felt an engine glitch or hesitation whilst driving you could quickly (whilst taking due care on the road) flick through some key parameter histories to see what just happened. Ran out of RAM trying to implement it in the display alone.
* Uses CAN interface to Megasquirt. (Its not as complicated or difficult as it sounds)
* Simple one wire bus over clock spring for steering wheel switches instead of analog multiplexing. (which was terrible.) Puts ~120ma of current through the clock spring contact to keep it clean.
* Code written in arduino IDE for fast OO code implementation and hopefully opens it up to a wider range of people to have a go at adding their own features.
* OLED display is shut down properly when IGN > off. (Apparently this can damage the display of not performed)
* Don't have to sacrifice horn function to use the clock spring for display functions.
Almost ready to start laying out a PCB which I will make available on batchpcb.com hopefully I can get it nice and small so it can be tucked in a corner of the cluster discretely with a short ribbon cable to the display - so minimal internal hacking of cluster required.
I've attached a pdf of the hardware schematic, feel free to critique.