How to connect a RESET button to the RP2040 RUN pin?

You can connect a reset button to the RUN pin of the RP2040 by:

• Connecting a pullup (10k) resistor from RUN to 3.3V, so it’s turned on when the button is not pressed.
• Connecting the button between RUN and GND, so when the button is pressed, the RUN pin is pulled to GND and the RP2040 resets.

While you can also add a capacitor between RUN and GND (e.g. 100nF) in parallel to the button, this is not necessary for most applications. It will prevent mechanical bouncing of the button, i.e. when you release the button, the RP2040 will reset multiple times in quick succession.