Uhcoog, I may finally be able to make some progress on the knock sensor front. I got a little digital oscilloscope for Christmas, so I've been trying to figure out things to use it on. It was mainly needed to help with my speedo conversion I've been working on, but I realized it would probably work well with the knock sensors as well. If I can make any sense of the stock wiring, I might be able to finally read some kind of signal out of them.
The premise seems easy enough. The Megasquirt additional knock circuitry should work if I'm interpreting it correctly. To my eye, it basically reads a signal and when any portion of the signal exceeds a threshold value (tuneable by the circuit), it triggers a pulse from a timer circuit to the MS processor. The trick is knowing what signal the sensor outputs so you can determine the threshold value for the trigger. A GM one wire might be a 1-5V kind of signal (total guess, probably wrong), and the Hemi might have more like a 0-1V output for all I know. An amplifier in line might be all that's needed to make the signal easier for the circuit to see. Hopefully the scope will be sensitive enough to catch a pulse where my analog ohmeter wouldn't. Unfortunately, I still have no idea if my sensor are even good to begin with.
