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Originally Posted by dcb
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Thanks. That's an interesting thread. I recall reading it early on.
Unfortunately, I have a huge amount of time invested in tracing the wiring harness on my vehicle, searching for alternate vss sensors, combing the service manuals for information, searching under the dash for speedo signal driver boxes (that don't exist in my model year), etc. Documenting in the wiki that mpguino does not directly support reluctor output would be a great addition. If I'd known that early on, I might not have gone that route.
So what I have is a reluctor vss sensor located in the differential that has worked reliably for 170,000 miles. I'd rather not kludge up additional hardware. It should be possible to get this very nice sine wave into a TTL form that mpguino can parse. And the results of that effort should be useful to others.
Is the frequency limit of the VSS input known? My biggest concern is that everything I've been doing is pointless because the input can't handle the frequency I need - 10 pulses/mph, or 700 hz at 70 mph. That's 36,000 pulse/mile.
I've had a few circuits that output decent TTL, but all of them seem to hit a wall on frequency with mpguino. It could just be that my voltages weren't in the right range, etc.