rp2040-pd-sniffer

RP2040 USB-PD Sniffer and Sink

This project provides two firmwares for a Raspberry Pi Pico or any other RP2040-based board to interact with the USB Power Delivery (USB-PD) protocol.

1. Sniffer: A passive USB-PD sniffer that listens to the communication on a USB-C CC (Configuration Channel) line, decodes the messages in real-time, and prints them to the USB serial console.
2. Sink: An active device that can negotiate a specific power profile from a USB-PD power adapter. This example is configured to request a 15V / 3A profile.

Features

• Shared USB-PD Library: All the common logic for decoding and encoding USB-PD messages is contained in a shared library.
• PIO-Based Sampling and Transmission: Uses the RP2040’s Programmable I/O (PIO) for both an 8x oversampled receiver (sniffer and sink) and a BMC transmitter (sink).
• Real-Time Decoding: Performs full, real-time decoding of the physical layer protocol.
• Self-Contained Build: The project is configured with a modern CMake build system and includes the Raspberry Pi Pico SDK as a submodule.
• Automated Builds: A GitHub Actions workflow automatically builds both firmware targets on every push to the main branch.

Building the Firmware

This project uses CMake and requires the ARM GCC toolchain.

Prerequisites

• git
• cmake
• gcc-arm-none-eabi

On a Debian-based system (like Ubuntu), you can install these with:

sudo apt-get update
sudo apt-get install -y git cmake gcc-arm-none-eabi

Build Steps

1. Clone the repository:

   git clone https://github.com/your-username/rp2040-pd-sniffer.git
   cd rp2040-pd-sniffer
   

2. Initialize the Submodules:

   git submodule update --init --recursive
   

3. Run the Build:

   cmake -B build -S .
   cmake --build build --parallel
   

4. Find the Firmware: If the build is successful, you will find the flashable .uf2 files inside the build directory:
   • build/sniffer.uf2
   • build/sink.uf2

Flashing and Usage

Sniffer

1. Flash the Firmware: Flash sniffer.uf2 to your Pico.
2. Monitor the Output: Open a serial monitor and connect to the Pico’s virtual COM port. You will see the decoded USB-PD messages.

Sink

1. Flash the Firmware: Flash sink.uf2 to your Pico.
2. Connect to Power Adapter: Connect the CC line of your circuit to a USB-PD power adapter.
3. Monitor the Output: Open a serial monitor. The application will print a message if it finds and requests the 15V/3A profile.

This site is open source. Improve this page.