Issues reading multiple analog inputs from a pinball machine

I'm reaching out with a bit of an S.O.S.

I am part of a team based in Toronto who are working on an art installation reappropriating and old early 80’s Bally pinball machine to trigger a new set of sounds and to provide a novel game experience.

Currently, we are having an issue generating useful trigger data from various switches on the play field, into an Arduino Mega, and using those impulses to trigger sound events on a Tsunami Super Wave Trigger.

Essentially the challenge we’re facing right now is converting the raw analog electrical impulses into useful digital impulses. We are able to get a signal from a single trigger source (voltage drop). But once we introduce multiple simultaneous sources, the data becomes erratic and unusable.

If you might have any insight, we would very much appreciate your consultation on this project.

Obviously this is a general description of the issue we are facing and we would be happy to expand upon/answer any questions you may have about previous attempts and methodology.

Thank you for your time.

Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html.

You could us opto-couplers to interface between the PinBall circuitry and the Mega, this will provide isolation electrically so you do not have problems with circuit voltage/current glitches/transients that the machine may have due to solenoid operation.

Can you tell us your electronics, programming, Arduino, hardware experience that members of your group may have?

Can you please post a copy of what you have tried with a circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Are all the signals gnd to supply transitions, AC or DC, what voltage?

Thanks.. Tom... :slight_smile:

Switches produce a digital (on/off) signal by nature, not an analog signal.

Indeed you will have to use optocouplers to isolate the electrical systems, as pinball machines are very noisy. High powered electromagnets switching on and off all the time and so.

Just an optocoupler may not even be enough - you may need additional filtering (either in hardware or software).