Crank / Cam VR Signal Generator
Posted: Sat Mar 24, 2012 6:40 pm
I would like to make a Crank / Cam signal generator to feed the VR inputs of an ECM. The crank pattern is 60 - 2, and the cam signal is either 1 or 7 pulses per 720 degrees of crank rotation (job related).
I'm not looking to accurately simulate the behaviour of a VR sensor, I just want to generate a signal that the VR input on the ECM would be happy with.
A +/- 5V sine wave pattern is what I think would be appropriate / acceptable.
We already have a couple of in-house designed signal generators.
One is a bit old and "funky" (generates appropriate pattern of square waves with a PIC and then run it through some op-ampery to generate a trapezoidial looking, bi-polar signal). The other generates the signals by driving coils surrounding actual VR sensors, but the design files are lost.
My initial idea is to generate the signals by using a sine lookup table and an R2R topology on 8 output pins of a uC and then couple the signal to an audio differential line driver IC.
Any suggestions would be appreciated.
Thanks,
Huff
I'm not looking to accurately simulate the behaviour of a VR sensor, I just want to generate a signal that the VR input on the ECM would be happy with.
A +/- 5V sine wave pattern is what I think would be appropriate / acceptable.
We already have a couple of in-house designed signal generators.
One is a bit old and "funky" (generates appropriate pattern of square waves with a PIC and then run it through some op-ampery to generate a trapezoidial looking, bi-polar signal). The other generates the signals by driving coils surrounding actual VR sensors, but the design files are lost.
My initial idea is to generate the signals by using a sine lookup table and an R2R topology on 8 output pins of a uC and then couple the signal to an audio differential line driver IC.
Any suggestions would be appreciated.
Thanks,
Huff