Radio Robot

Radio Robot is the firmware and host software for the DFRobot QBot Pro — a micro:bit V2 paired with a Nezha V2 motor board. The robot runs a C++ CODAL firmware that takes movement and sensor commands over USB serial and micro:bit radio, executes them on the hardware, and streams telemetry back to a Python host.

This page is the quick tour. Deeper material lives in the repository and is linked throughout.

How the pieces fit together

  Python host  ──serial / radio──►  micro:bit V2  ──I2C──►  Nezha V2 motors,
  (robot_radio)   protocol v2          (firmware)            OTOS, color, servo
       ▲                                                          │
       └──────────────── telemetry (OK / EVT / TLM / ID) ◄────────┘

• Firmware (source/) — C++14, no heap in the hot path, layered into types / hal / control / app / nav. It owns the command processor, the ratio-PID motor control, dead-reckoning odometry, and the pluggable path-following / pose-provider interfaces.
• Host library (host/robot_radio/) — the canonical, tested Python package for all host-side robot interaction. Everything that talks to the robot goes through it: motion, config, sensors, navigation, path planning, kinematics.
• Wire protocol — newline-terminated ASCII commands with sign-prefixed integer arguments (+1234, -42). Serial runs at 115200 baud; radio uses group 10 with >/< relay prefixes for wireless operation through a second micro:bit.

What makes it interesting

• Ratio-PID motor control. Instead of plain velocity PI, the firmware tracks cumulative encoder distance per wheel and runs a PID controller on the normalized distance ratio between wheels, which kills long-run drift.
• Arc-to-goal G command. Computes an arc from the current pose to a relative XY target (optionally pre-rotating on large heading error) and drives it with encoder targets — point-to-point navigation without continuous pose feedback.
• Pluggable navigation. PathFollower (PurePursuit, Stanley) and PoseProvider (OTOS, dead-reckoning, future external camera) are pure-virtual interfaces selected at runtime.

Start here

Source of truth lives in the repo. This wiki summarizes and points back to League-Robotics/radio-robot; the linked files are always the authoritative version.