Coil triggering solution

[hemiaction]

On my Harley davidson we decided too control fuel only with the microsquirt and tryed too get the rpm signal from the coil , everyone that have tryed that mabe have burned the resistor R 20 or burned the optoisolator inside microsquirt, after struggeling alot with this issue i ended up with a very good signal from the coil that i could use , i think this will also work for others that wanted too run on "fuel only" . When we hooked up optin+ too the coil negative and the optin- too a switched 12v+ we get a very
strange rpm signal , the rpm was nearly doubled and everything was wery erractic , not useful at all everything hooked up after the manual, We put a 4.7kohm resistor between optin- and the 12v+ switched , On the other side i used a 500 ohm resistor between the coil negative and the optin+ This worked for me and the rpm signal is clean all over the rpm band , i am using a 2.4 ohm coil on this bike , I hope somebody will have help of this posting here , i should like too see more postings with good solutions , not only trouble, when people have come too and end post your setup , it could be of good help for somebody.
Thanks Lars