Keyboard and Mouse Not Working Together?

TPR

Having a strange problem I've never noticed before. I'm using a fairly standard no-frills Logitech wireless mouse with a fairly standard, no frills wireless keyboard. Both use USB dongles. I've had these working together for quite some time on my Pi 4 build, but today, I noticed that if both of them are plugged in together. The mouse no longer works, for example in light gun games like Duck Hunt or T2. But if I unplug the keyboard dongle, it works just fine.

Like if I'm in Duck Hunt, and both USB dongles are plugged in, the mouse doesn't work. The second I remove the keyboard dongle, the mouse works just fine.

Oddly enough, it does not seem to be the other way around. The keyboard will work just fine even if the mouse dongle is attached.

This only started happening recently and I have not made any changes to my RetroPie setup. Any ideas or things I can try to fix this?

TPR

OK, I've got an update... and this makes no sense to me, but...

If one of the dongles is plugged into the Pi 4 board and the other dongle is plugged into a USB hub. They work fine together.

It gets even weirder...

If the Mouse USB dongle is plugged into the Pi 4 board and the keyboard dongle is plugged into the USB hub, they do not work.

It HAS to be the mouse USB plugged into the hub and the keyboard USB dongle plugged into the Pi 4. And then they both work perfectly fine together... no issues.

What would cause this to be happening?

mitu

@tpr said in Keyboard and Mouse Not Working Together?:

What would cause this to be happening?

What kind of keyboard are you using ? It may add an additional mouse-like device which shifts the mouse index used by the actual mouse. The index is used by the emulator to know which mouse is the lightgun.

YFZdude

Another possibility: This reminds me of an RF noise issue I had.

I've noticed that when I have a wireless keyboard plugged into a USB port on the front of my PC, and I also plug in the wireless Logitech F710 controller to the second port right next to it, they don't always respond properly, even if I use an extension cable on one of them. But if I move one of them to a different USB port in the back of the PC which would have a different controller chip on the board, they play nice.

If one of your devices is emitting a lot of noise, the USB hub could either be cleaning up the noise before passing the signal to the Pi, or amplifying the noise as it passes the signal. You could try plugging one of them into the USB 3.0 ports and the other into the USB 2.0 ports to see if that helps, but it could still be a problem due to how close they are together.

TPR

@mitu It's honestly just a super basic, no frills, nothing special keyboard. I did also think about that whole mouse index and wonder if it was maybe giving priority to the keyboard, but then I actually did a test with a simple Dell wired keyboard and it did the same thing. It was seriously weird af.

Here's the keyboard I am using:
https://www.amazon.com/gp/product/B073TSKFRX/