Hi forums!
I'm trying to read engine RPM by sensing a pulse.
The pulse i was taken from Tachometer i took 1 wire that sending pulse to Tachometer
( i've tested attaching led )
So the goals is to receive that pulse signal into arduino, i can't just connect it directly to arduino since the pulse is using working with different voltage , so I'm using optocoupler to sending the pulse to arduino.
I'm using
attach interrupt() function to calculate the rpm
The program works but the reading is not accurate, i assume there's still a noise signal ? Since the optocoupler operated from engine power supply ?
No, i don't have any oscilloscope so i can't figure out.
I was wondering is there any shield isolated shield available for arduino? So each IO input is isolated
Edit :
The Tachometer is digital, the engine itself has 12 pulse per rotation, how do I know ? Because the engine has 12 magnet for pulse pickup for the ECU
I'm using optocoupler module that already has resistor to operate from 12v