(2020-11-04, 05:01 AM)Techstyle Wrote: I have removed the 470K resistor and replaced it with a 10K meaning both R1 and R2 of the circuit below has 10K resistors
I just got a new Pi 4 today, so just setting up and I will see if it works - Thanks
The second resistance - R2 - must not be changed.
The input is over 12 volts and that's too much for the optocoupler but the output works with the 3.3 volts of the Rpi and the original resistor is adequate.