PiLogger

Hardware keyboard logger using a Raspberry Pi Pico + Raspberry Pi Zero 2W

Features

• Clone vendorId and productId from the connected keyboard to the target machine.
• Forward all keystrokes to the target machine.
• Log pressed keystrokes.
• Forward LED states (Capslock, Numlock, Scrolllock) to keyboard.

How to use

Configuring Raspberry Pi Pico

The code for the Pi Pico can be built using the Arduino IDE using the following procedure:

• Add the URL and install the package for the RP2040 boards:

https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json

• Install the Adafruit TinyUSB library
• Select your RP2040/RP2350 board and change the USB Stack to "Adafruit TinyUSB Host (native)"
• Compile and flash the code to the board

You can check if the Pico is working by connecting a UART reader to Serial1 (GP0 TX and GP1 RX, Baud Rate 115200) and check the messages sent when connecting a USB keyboard to the board.

Configuring Raspberry Pi Zero 2W

The Pi Zero 2W has to be configured to act as a USB Gadget device.

• Edit the file /boot/firmware/config.txt and add the following lines at the end:

enable_uart=1
dtoverlay=dwc2,dr_mode=peripheral

• Add the required modules to /etc/modules:

libcomposite
dwc2
uinput

• Clone the repository, create a venv and install the required packages:

git clone https://github.com/RafaelDiasCampos/PiLogger.git
cd PiLogger
python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Connecting the Raspberry Pi devices

The Pi Pico uses the Serial1 port to send and receive data. Connect it to the Raspberry Pi Zero 2W like this:

Pico GP0 (TX)   ->   Zero 2W GPIO 15 (UART RX)
Pico GP1 (RX)   ->   Zero 2W GPIO 14 (UART TX)
Pico GND        ->   Any Zero 2W GND pin
Pico 5V         ->   Any Zero 2W 5V pin

Starting the keylogger

To start the keylogger, run the Zero2W Logger/main.py as root. After connecting a keyboard to the Pi Pico you should see the pressed keys logged in the keyboard_log.raw and keyboard_log.txt files.

How it works

This project uses the RP2040/RP2350 board in USB host mode to connect to the keyboard and receive the pressed keystrokes. They are sent to the Zero 2 W via UART and interpreted by the Python script, which prints it to the console and optionally logs the text typed to a file. The Zero 2 W is configured in USB device mode to simulate the keyboard and send the keys pressed to the computer. USB IN commands, sent when toggling the keyboard LEDs, are received by the Zero 2 W, sent to the Pi Pico via UART and sent to the USB keyboard. In summary, the data travels according to the following:

USB Keyboard <-> Pi Pico in Host Mode (RP2040/RP2350) <-> UART <-> Pi Zero 2 W in USB gadget mode <-> Computer