Mechanical to Electrical Tachometer Conversion

I'm doing this at the moment - My Renault originally had a cable driven speedo and a coil driven tacho. I've now got an engine with coil-on-plug and a gearbox with no speedo drive, so neither work.

I'm using Arduinos to count pulses from an ABS sensor for the speedo and a supplementary crank sensor reading a custom toothed wheel attached to the crank pulley for the tacho. These arduinos drive little stepper motors mounted behind the instrument face to move the needles.

Have a look at this:

retromini.weebly.com/blog/arduino-speedometer

That's not my page/conversion, but my own conversion is 'inspired by' (read: basically copied lock, stock & barrel) that person's work which he's graciously made available for the less electronically adept of us! Luke Hurst, if by some chance you're reading this - thanks

My own setup adds a MAX9926 VR sensor conditioner board to pass the ABS signal to the arduino. I'm using an Uno to easily get everything working but it'll be changed to Nanos for integration into the cluster.