Axon: an open source USB bridge for robot I/O
One board replaces dongle piles with stable Linux devices and CAN FD.
Axon is an open source USB bridge designed to simplify robot I/O by consolidating multiple bus interfaces into a single board. It supports half-duplex TTL for servos, two UART ports, RS485 for motors and Modbus, CAN FD with dual connectors, I2C via Qwiic, and a 9-DOF IMU. The board exposes everything as standard Linux devices with stable names like /dev/axon_serial0 and socketCAN can0, eliminating the pain of reordering /dev/ttyUSBx on every reboot. Per-bus activity LEDs and a boot-time sniff mode that captures all traffic with direction tagging make debugging easier without extra hardware.
Under the hood, Axon is built on an RP2350 microcontroller, allowing users to flash custom firmware for tighter timing or local sensor fusion. The hardware and firmware are fully open source, with a modular design where the Axon core module can be paired with custom carrier boards via a KiCad template. Prototypes are validated, and the project is heading to Crowd Supply soon. The developer, dragomir.xyz, is active on the ROS forum and plans to release example repos for PicoROS and zenoh-pico integration.
- Consolidates TTL, UART, RS485, CAN FD, and I2C into one board with stable Linux device names.
- Built on RP2350, supports custom firmware for real-time control loops at kHz rates.
- Includes per-bus LEDs and a sniff mode for debugging without a logic analyzer.
Why It Matters
Ends the dongle pile and device name shuffling, streamlining robot I/O for ROS developers.