This is a quick look at how I bring the RPM signal into the Raspberry Pi data acquisition computer.
Items Involved:
MAX 9926 development board for converting the analogue signal to a digital signal.
Adafruit: Logic level converter TXB0108: for converting from 5.0-volt logic to 3.3-volt logic.
Link to pigpio library:
abyz.me.uk/rpi/pigpio/
Click on Examples
Then Python Code
Then scroll down until you see RPM Monitor,,,, that will be the one I used.