USB communications The micro:bit has an on-board USB communications stack, that is built into the firmware of the interface chip. This stack provides the ability to drag and drop files onto the MICROBIT drive in order to load code into the application processor. It also allows serial data to be streamed to and from the micro:bit application processor over USB to an external host computer, and supports the CMSIS-DAP specification for host debugging of application programs. Interface The interface chip handles the USB connection, and is used for flashing new code to the micro:bit, sending and receiving serial data back and forth to your main computer. Due to parts availiability there are two variants of the V2.2X devices with a different interface chip; a limited run of devices were built using the nRF52833-QDAA and further devices are built using the nRF52820-QDAA. As the two chip variants are of the same family, the same DAPLink firmware image runs on both chips and it provides the exact same functionality. "

The micro:bit has a combined accelerometer and magnetometer chip that provides 3-axis sensing and magnetic field strength sensing. It also includes some on-board gesture detection (such as fall detection) in hardware, and additional gesture sensing (e.g. logo-up, logo-down, shake) via software algorithms. The display is a 5x5 array of LEDs. It is connected to the micro:bit as a 5x5 matrix. Runtime software repeatedly refreshes this matrix at a high speed, such that it is within the user persistence of vision range, and no flicker is detected. The NRF52 application processor has an on-board core temperature sensor. This is exposed via the standard runtime software, and provides an estimate of ambient temperature.In addition to outputting sound via PWM on the pins, the micro:bit has a PCB mounted magnetic speaker to which sound output is mirrored. The on-board 2.4GHz supports Bluetooth communications via the Nordic S113 SoftDevice, which provides a fully qualified Bluetooth low energy stack. This allows the micro:bit to communicate with a wide range of Bluetooth devices, including smartphones and tablets. The nRF52 application processor is where user programs run. A single, complete application including user code, runtime code and Bluetooth stack is loaded and run directly from on-chip flash memory. There is an on-board 2.4GHz radio peripheral used to provide Bluetooth and custom radio capabilities via an off-chip aerial.