Outlook

While the micro:bit's MicroPython software is documented in detail [5], the hardware is not. The outputs are probably short-circuit proof; they possibly also limit the current to 10 or 90mA. However, there are no reliable statements about this. For this reason, you should only connect light emitting diodes via a protective resistor.

The microcontroller has a wide range of internal interfaces; it can handle I2C, SPI, LIN, and UART, as well as USB and USB OTG. Many of the 23 inputs/outputs are also routed to the outside, but only as simple PCB plug contacts, which can only be used with a special connector.

Calliope Mini [6], a project managed by Germany's Calliope gGmbH, describes itself as a further development of the micro:bit. Calliope Mini circuit diagrams and software are freely available as open hardware or open source, and there are also several manuals as open educational resources.

Calliope Mini's circuit board has additional sensors like a microphone and loudspeaker, as well as four I/O contacts for crocodile clips (instead of the micro:bit's three I/O contacts). The two modules do not differ in terms of memory size. The Calliope developers route all other interface contacts to the outside via an easily accessible pin headers. This might be a more reliable solution than the extension board required for the micro:bit. On the other hand, the community and its comments on the Internet are much more for micro:bit than for ohter MicroPython-based educational boards.

Conclusions

The BBC micro:bit offers an introduction to microcontroller programming and teaches how to use modern high-level languages like Python.

However, the MicroPython interpreter eats up memory and impacts speed. If you are looking to push a microcontroller to its limits, Arduino and its programming environment are a better option.