Need A USB Sniffer? Use Your Pico!

Ever wanted to sniff USB device communications? Traditionally, this required expensive hardware, logic analyzers, or cobbling together development boards with custom software to forward USB data. Now, thanks to ataradov’s work, you can achieve this using a Raspberry Pi Pico. By tapping the D+ and D- pins and wiring them to the RP2040’s GPIOs, you can monitor communications between your computer and low-speed (1.5 Mbps) or full-speed (12 Mbps) USB devices.

To use this setup, simply connect the Pico to your computer, open the virtual serial port it creates, and you’ll see the USB packets streaming in. This solution provides an elegant and cost-effective USB sniffer with only minimal soldering required, utilizing the affordable Pico.

ataradov has also designed a complete board with an RP2040 and a USB hub, which includes USB sockets, eliminating the need for soldering. This open-source KiCad design allows you to order custom sniffers from your preferred fabrication service. This project serves as an excellent learning tool, combining simplicity, affordability, and the potential for reverse-engineering both old and new systems.

Pairing this USB sniffer hack with another Pico handling USB device or host roles, and familiarizing yourself with USB reverse-engineering fundamentals, could enable you to create a Facedancer-like tool with ease. This project not only makes USB sniffing accessible but also opens up numerous possibilities for enthusiasts and professionals alike.

Read more: Need A USB Sniffer? Use Your Pico!