Geo TP's Open Source Firmware Turns an Espressif ESP32 Into a Bus Pirate-Inspired Multi-Tool

Pseudonymous developer "Geo TP" has taken inspiration from Dangerous Prototypes' Bus Pirate family of electronic multi-tools, building a firmware that replicates as much functionality as possible onto a range of Espressif ESP32-based development boards.

"ESP32 Bus Pirate is an open source firmware that turns your device into a multi-protocol hacker's tool, inspired by the legendary [Dangerous Prototypes] Bus Pirate," Geo explains. "It supports sniffing, sending, scripting, and interacting with various digital protocols (I2C, UART, 1-Wire, SPI, etc.) via a serial terminal or web-based CLI [Command-Line Interface]."

Geo wears the project's inspiration proudly, to the point of even borrowing its name. The original Bus Pirate was launched by Dangerous Prototypes' in 2008, and since then Ian Lesnet has developed a range of firmware improvements and successive designs culminating in the Bus Pirate 5 that launched last year.

Geo's take on the project, though, doesn't require custom hardware; instead, it's designed for compatibility with off-the-shelf development boards built around Espressif's ESP32 microcontroller family. At the time of writing, the project supported Espressif's ESP32-S3-Dev-Kit, the M5Stack Cardputer, M5Stick C Pluls 2, Atom S3 Lite, M5Stamp S3, LILYGO T-Embed, and the T-Embed CC1101.

Features implemented include I2C, SPI, UART, 1-Wire, 2-Wire, and 3-Wire, I2S, and CAN bus connectivity, digital input/output, USB, infrared send and receive, Bluetooth, Wi-Fi, and JTAG debugging. There are protocol sniffers for I2C, 1-Wire, and CAN bus, auto-detection for UART baud rate, and support for scripting using Bus Pirate-style bytecode instructions.

The project is documented in full on GitHub, where the source code is made available under the permissive MIT license; Geo warns, however, that "devices should only operate at 3.3V or 5V[DC}," and that connecting peripherals running at other voltage levels "may damage your ESP32."