alright, i'm back at coding and my plan is to add chris' air pump controller to my solenoid controller for a unified controller that takes less space than the two separate controllers. the hope is to add the following functionality:
RPM telemetry back to the transmitter (because, why not since we'll have that data)
prime the engine from the transmitter (chris already has this)
use a single transmitter channel for both mixture control and for priming (why not use a 2000uS pulse to initiate priming, after all, we would never need a 2000 uS pulse for the solenoid channel anyway and the solenoid should be fully opened during priming procedures anyway.)
i have a few questions for you chris. i haven't connected one of my ignitions to one of my oscilloscopes. i believe your design uses an optocoupler for the RPM signal from the ignition to the controller, and i believe you're using a 5v arduino pro mini (maybe not). the seeeduino xiao will only allow 3.3v max into a pin before letting the magic smoke out so i was planning on using a simple 2 resistor voltage divider to scale the RPM signal to less than 3v, and likely closer to 2 or 2.5v for a bit of safety since 1.8v or above is considered a logic high input. did you take any measurements of the RPM signal and if so, what voltage can i expect on that wire from the CDI?
your code has 255-40 = 215 distinct steps for the air pump output. have you found that to be sufficient or should i attempt to get a higher resolution from the pin controlling the air pump like i did with the solenoid control pin on my controller?
i seem to recall you were using a needle valve bleeded to allow the tank pressure to drop when the pump slows down. did you just guess at the setting or did you measure the pressures attained with muffler pressure and try to duplicate that with the pump?
does this setup eliminate the need for a crap trap all together or did you still require something to keep fuel from backing up into the air pump? it's been a while and my memory is no longer fresh.
you've been using this method for a while now. if you were to make any other changes to your setup, what would they be, because now's the time to implement new functionality while i'm at it.