[Second Series]

A 5volt regulator to feed the square wave into the Arduino. The signal can be converted from 40 pulse per driveshaft rev to 128,000ppm, 4,000ppm and 2,000ppm in the software. A potentiometer can be used to adjust for tire size and gear ratio. The 128,000ppm looks like a modified square wave on my truck, A differentiator will produce that signal. It looks like the 4,000ppm is 5v, and the 2,000ppm is 12v. The Arduino operates at 5v so a transistor switch can bump the signal up to 12v.
I’ll need to order some components and breadboard this. I’d like to set up a reluctor ring and sensor on my bench so I don’t need to jack up the truck when I’m trying to figure this out.