micro:bit firmware
Overview
The micro:bit has a separate interface chip dedicated to USB connections, programming, and debugging. This chip runs DAPLink firmware from Arm Mbed, providing drag-and-drop programming, a serial port, and a debug channel.
Code editors produce .hex files that are copied onto the micro:bit via the USB drive interface. The Universal Hex format allows a single hex file to work on all micro:bit versions.
Specifications
The interface and target MCUs on the V2 micro:bit communicate using documented protocols:
- I2C protocol specification — communication between the interface and target MCUs
- Power management specification — collaborative power management between the two MCUs
- Universal Hex format specification — the file format for cross-version compatibility