Nyemi, thanks for your help.

If the hall input is really as dirty as the trace Nyemi posted then I think that is a problem. It would be good to put some low pass filtering on the hall input. Perhaps someone can do some calculations to find the proper cutoff and values.

Maybe some experimentation with the pull-up resistor on the hall line could also help with this.

One thing I can try is turning off the INTE in the GP2 ISR and then turning it back on after the spark fires. That should make sure that no interrupts are generated from random noise while the hall is on (low).


I've got some time today and the engine is here with me for testing. As soon as the locktite on the hall sensor mount dries I'll start testing things out. Should have done it last night, but didn't think of it.

It won't hurt to think of ways to possibly make the hardware setup a little smoother. A wee bit of analysis and tweaking might make things more reliable as far as the signals that the PIC sees. I really should have scoped things out better, but now that I have the engine running I'll have a better idea of the actual signal environment. If the hall signal really is that dirty then I think the falling edge is the way to go since it seems like a dirty signal when it's activated (low), but clean when it's off (high).

In any case stay tuned to the thread, the problem will be solved today.


-Jake