I have a Raspberry Pi 4 running Raspbian Lite. On that I soldered an Adafruit Hat + RTC and connected Adafruit 64x32 RGB Matrix. I have also connected a GPIO push button to pin 5 & GND#4

For the software, I'm using the python3 bindings from hzeller's rpi-rgb-led-matrix library.

The issue I am having is the matrix is interfering with the GPIO button. When the matrix is not configured, the button signals successfully (python print statement fires) when the matrix IS configured, the print statement does not fire and the top of my matrix flickers green. See attached images.

Matrix when button is not pressed: button not pressed Matrix when button is pressed: button pressed My configuration: my configuration

Bonus scenario: alternate pins I found if I move the pins my button is wired to, I can cause different affects on-screen. Switching to this pin and pushing the button caused every other line to be cut off.

I don't know if it's a software issue or a hardware issue causing the inputs to clash. Any ideas what would cause this?

  • 2
    The Adafruit HAT documentation tells you which GPIO it uses. Make sure you don't use them.
    – joan
    Jul 25, 2022 at 9:47
  • 1
    According to the schematic, the hat uses many pins. According to learn.adafruit.com/…, among others GPIO19 = pin 35 seems to be free (if I read this correct).
    – Bodo
    Jul 25, 2022 at 11:03

1 Answer 1


The matrix hat used a number of additional pins. I just needed to take another peak at the documentation.

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