Vehicle Tachometer

I'm a technical educator who likes to develop fun projects and share them.

This is a microcontroller powered electronic tachometer and rev counter for cars.

it has a unique self tune capability and can work with any engine with any number of cylinders. Just install it, rev the engine to mid level and press a button. The tachometer learns the signal/rev ratio of the engine and start displaying the tacho value accordingly. 

The circuit needs a pcb to be built. please sponsor me.

thanks.