Hi there I’ve come into bit of a problem with using the Feather 2040 and the LED Arcade Button 1x4 - STEMMA QT I2C Breakout. The buttons are wired up correctly and im using some basic functionality to make the buttons light up and press a keyboard keys from 1 to 4. However i’m getting a reocurring …

Hi Murlo, From the code, it looks like Button 4 is on Pin 2, but Pin 21 is being initialised. Could that be the problem?

I also think this is the root cause. Pin 2 is SDA, this explains the flickering.

Adafruit Feather 2040 with LED Arcade Button 1x4 - STEMMA QT I2C Breakout

murlo February 5, 2026, 6:11pm 4

thank you so much this was the root of the problem!

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