Phantom Inputs with a USB Encoder

[Mystrandir]

So I've been having an issue with a Pi build and I'm curious if anyone else has experience it or has advice. I'm using a Pi 3b with Retropie and this encoder: https://www.amazon.com/Reyann-Arcade-Encoder-Joystick-Fighting/dp/B00UUROWWK/

When hooked up my controls (Sanwa stick, Happ buttons) are responsive and read input correctly. The problem is that when the controls are idle the system is reading phantom inputs from the device. Using evtest and watching the output I'm getting approximately 1-2 false inputs per minute. Some of the inputs are by themselves and some are multiple buttons being activated at once. This is causing an issue as periodically the buttons mapped to Start and Select are activated together, causing games to exit erroneously, as well as all the other problems you'd expect from a game getting input you didn't give it.

Does anyone happen to have experience with something like this? The research I've done makes me think that there may be an issue with the power from the Pi USB ports not being consistent, which causes the encoder to think a button is being pressed. I'm inclined to try a powered USB hub but wanted to see if anyone else had advice before making that purchase.

[Namco]

I would double check your grounding. Make sure all buttons' connection to ground is good and solid. Use both ground connections on your encoder. Also make sure you don't tie the encoder ground with any other ground on the cabinet like chassis or audio or PC ground or anything.

Also keep your wires to each button short. Long runs might be causing an intermittent voltage drop. If you need long runs, consider adding some capacitors to the mix. Maybe the whole encoder board seeing a voltage drop? Maybe the encoder board is faulty or there's a bad cap on the board itself?


EDIT: Oh, hey just saw the pic of the encoder. It's probably one of the caps on that board or USB ground is intermittent. Those are cheap enough

EDIT: Check out the 1-star reviews. Some good suggestions in there, one says one of the connections doesn't have enough solder. Maybe reflow the headers. https://www.amazon.com/Reyann-Arcade-Encoder-Joystick-Fighting/product-reviews/B00UUROWWK/?ie=UTF8&filterByStar=one_star&reviewerType=all_reviews#reviews-filter-bar

[Mystrandir]

I would double check your grounding. Make sure all buttons' connection to ground is good and solid. Use both ground connections on your encoder. Also make sure you don't tie the encoder ground with any other ground on the cabinet like chassis or audio or PC ground or anything.

Also keep your wires to each button short. Long runs might be causing an intermittent voltage drop. If you need long runs, consider adding some capacitors to the mix. Maybe the whole encoder board seeing a voltage drop? Maybe the encoder board is faulty or there's a bad cap on the board itself?


EDIT: Oh, hey just saw the pic of the encoder. It's probably one of the caps on that board or USB ground is intermittent. Those are cheap enough

EDIT: Check out the 1-star reviews. Some good suggestions in there, one says one of the connections doesn't have enough solder. Maybe reflow the headers. https://www.amazon.com/Reyann-Arcade-Encoder-Joystick-Fighting/product-reviews/B00UUROWWK/?ie=UTF8&filterByStar=one_star&reviewerType=all_reviews#reviews-filter-bar

I appreciate the reply. If I was to attempt reflowing (first time I've heard of this but I believe I understand after researching) would I want to apply additional solder and then go through the heating process, or just attempt to melt the existing solder and more firmly set the headers? I assume the former since the issue could be a lack of solder.

I actually have two of these encoders since my first thought was that the one I'd purchased was defective, but they both behave the same way.