RubberDucky Installation

Flashing CircuitPython

So how do we set this thing up?

First, we need to flash a firmware to the chip — in our case CircuitPython.

1. Download the .uf2 file here.
2. Hold the BOOT button on the RP2040 while plugging it into your PC. This will mount the board as a drive.
3. Drop the downloaded image into that drive and you’re done!

Installing the Code

Our code is hosted on Gitea here.

Start by creating a local copy anywhere on your computer:

$ git clone https://git.magnusku.de/Magnus/ruber-ducky

Then plug in your microcontroller.

If you’re on Linux, execute flash.sh from the project directory. It will detect the mount point and copy the project files over automatically.

On Windows, you’ll need to do this manually.

That should be all!

How to Debug

Now that the RubberDucky is armed, we need another way to update the code without triggering it.

For this purpose, there is a check on boot (in boot.py) that enables debug mode when GPIO pin 0 is pulled to ground. This stops keystroke injection and enables drive mounting for code access.

Simply connect the two pins with a jumper before plugging the board into your PC.

The board’s LED will blink blue when debug mode is enabled.