I need some advice from you guys.
I want to make a digital tachometer for my motorcycle. After some research, for most modern bike, we can read the pulse signal from pickup coil instead of ignition coil.
From my understanding, the pickup coil will send (12v?) signal to CDI unit, then send signal to plug coil to fire at correct timing.
I found this (See image: Instrustable.jpg) on Instructables. As you can see he connect the wire from ignition coil > R1 > R2 and feed arduino nano.
So my question is..... Can I follow his method? Use resistors to pull down the voltage from 12v to 5v to feed arduino nano to read the pulse signal? is it safe?
I have drawn the schematic. see image "RPM.jpg".
Thanks in advance guys!