Am not quite sure if this is HW problem, but i can not detect any impulse. The tested code is working OK when i try to read impulse changes manually ( over switch ). But when i hook up coin machine, nothing happens.
I use pin 5 of coin acceptor which is passed to pin2 of arduino board. GND is also connected between PIN2 - GND.
The coin acceptor outputs are all open collector so i put 5,4kOhm resistor on the coin line.
Now, if i measure voltage before the resistor and when i insert coin, i get readouts from 1,14 - 0,2V so it sends signal. I have measured between coin power supply (GND ) and pin 5 of coin selector.
So, why can i not read out this change on digital pin ? EDITED: If i measure voltage change directly on pin 5 of coin acceptor and GND of c.a. i get "correct " voltage values: 1Euro = 0.2 V 2euro = 0.45V 5euros= 0.67V
So the impulses are here...