I’m creating a rain curtain, 64 x 12V solenoids switched through 8 x 8way relays, these are controlled by an Arduino UNO through 8 x extender modules (FR12C PORT iNTERFACE pcf8574t i/o)
The relays run perfectly until I apply voltage to the 12V side, then it stops.
I’ve watched videos about grounding issues between the relay and the UNO that suggest seperating the power to the relay control from the UNO, but I can’t get it to run without ground coming back to the UNO.
Any ideas?
Nick