@nzmikec said in EXT unit to measure engine RPM:
..... i2c device to count these pulses and send my device an RPM value.
What is the device you're going to use to receive the values on I2C?
Maximum RPM (and pulses per minute) would be 11,000RPM.
Maybe you don't need an external device for counting. 11,000 RPM with 1 pulse pr revolution is about 190 Hz which an ESP32 should be able to count directly by it self via one of its GPIO's.