LOL, I like the "Space Shuttle" characterization
I did try it, and it was still bouncy (would drop to 17 from 27mph on occasion).
Tried a couple other things:
1. track the last 3 pulse time stamps and do a "vote", still wonky
2. track last 4 vss pulse lengths and average. Better, but jumpier than just vss tic count per half second.
3. keep track of the minimum pulse timing (max speed), reset when instantmph() is called (every 1/2 second). Actually was pretty consistent reading, a couple minor jumps, but it was really off. @20mph the guino was saying 35mph.
4. keep track of the maximum pulse timing (min speed), reset when instantmph() is called. Even more consistent, but also off. @20mph the guino was saying 12mph.
So something to mull over anyway.
I also did some coasting with the raw instant screen to see how the vsspulse looked. The number of pulses per half second would drop smoothly, not dropping more than 1 pulse at a time when slowly decelerating. So the counter logic looks good, just this instant timing is hard to nail down.
I got some metro bits from coyote (thx coyote/shultz!) so will probably hook up a reed switch on the bench and hack at it, and dissect an ECU