Overdrive control circuit for the C4 Corvette with the 4+3 transmission.
Tinker Circuit available here: https://www.tinkercad.com/things/iZJR47I1peG
main.cpp is the code as it was written.
whatiflashed.cpp includes a few adjustments I needed to make for quirks in my hardware, specifically inverted first gear detection and some weirdness with my relay control.