Using Arduino (i got leonardo and uno), I'm looking for a way to get the RPM of my car's engine. I know this can be done using an OBD2 connection however i'm looking for a different way.
I need a reference for a sensor / a creative way to get this data.
Having said that, these approaches came up:
- guessing the RPM by reading the amps in the car's 12V connection
- recording the sound of the engine using a microphone and setting thresholds for certain RPM values