While the BBC micro:bit has hardware capable of allowing the device to work as
a Bluetooth Low Energy (BLE) device, it only has 16k of RAM. The BLE stack
alone takes up 12k RAM which means there’s not enough memory for MicroPython
to support Bluetooth.
MicroPython uses the radio hardware with the
radio module. This
allows users to create simple yet effective wireless networks of micro:bit
Furthermore, the protocol used in the
radio module is a lot simpler
than BLE, making it far easier to use in an educational context.