I've converted an old EM pinball machine using arduino mega. Inputs are digital and they and the scoring works perfectly. Problem is the left flipper and at least one of the pop bumpers will false trigger a digital input and score 1,000 points.
All solenoids run off 24VDC. Score reels and chimes are controlled via MOSFETS via the arduino.
Flippers, pop bumpers and kickers (sling shots) are operated by directly applying 24VDC.
I've opto coupled the digital inputs, changed from active low to active high, run the switch contacts wires away from the wires to the solenoids, put a 10,000uF cap on the 5VDC rail, powered the arduino mega on the PC USB port, run the 24VDC solenoids on a 24VDC battery, I've got a cap across the EOS contacts on the flipper, separated the two voltage grounds, connected the two voltage grounds. It's hard to run the flipper solenoid via a MOSFET but I did with the offending pop bumper and the false triggering still occurred.
I can't think what else could be causing this issue.
Does anyone have any ideas before I burn this pinball machine to the ground?
The solenoid operated scoring reels don't effect the digital inputs and most of the other solenoids on the play field don't affect the digital inputs, just seems to be the left flipper and one pop bumper.