I'm trying to build a digital tachometer for my motorcycle using an Arduino nano. I have researched a lot on how to reduce the 12 volts from tach signal to 5 volts to be read by the arduino. One post here suggests using a voltage divider using zener diode.
The tach signal from the motorcycle is a square wave and quite high frequency. I'm not sure if the zener diode can handle frequencies like this. I'm not sure how the frequency is calculated but if its coming from the alternator, it will be very high.
Since I'm completely new to electronics, I would like to know if this will work with a zener diode or i should be changing something?