A few days ago I had the great opportunity to attend an event organised in collaboration with Python Software Foundation, a few primary school teachers and hosted by Computing at School, in London. The meeting was organised by Yvonne Walker (from CAS) and Nicholas Tollervey (PSF). The aim of the meeting was for teachers and developers to meet and discuss the opportunities offered by MicroPython on the BBC micro:bit. During the event a BBC micro:bit board was loaned to each person for the purpose of developing Python scripts, MicroPython itself or educational resources for the BBC micro:bit. Nicholas made it very clear that there is an NDA in place until the device is delivered to the kids and explained what we could or couldn’t do.

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The Board

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The board is a 4 x 5 cm device with an ARM Cortex-M0 processor, accelerometer and magnetometer sensors, Bluetooth and USB connectivity, a display consisting of 25 LEDs, two programmable buttons, and can be powered by either USB or an external battery pack (source: https://en.wikipedia.org/wiki/Micro_Bit ).

Flashing the firmware

Once you get a new board, it probably doesn’t have a proper firmware and application flashed. I suggest you to download the Python MicroBit REPL from this repository: https://github.com/ntoll/microrepl
All you need to do is to connect the board to your computer, using a micro-USB cable. The device will be mounted as a volume. At this point, drag & drop the file called firmware.hex into the mounted volume. The firmware will be flashed and during the operation you will see a yellow led flashing.

Using MicroPython micro:bit REPL

To start writing some Python code on micro:bit you first need to clone this repository

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git clone [email protected]:ntoll/microrepl.git

once you have cloned the repository, you need to install the Python dependencies (I suggest you to do it from inside a virtualenv)

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pip install -r requirements.txt

start the MicroPython REPL

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python microrepl.py

and the Python shell will open, so you can start writing commands, like this one

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(microbit)➜  microrepl git:(master) python microrepl.py
Quit: Ctrl+] | Stop program: Ctrl+C | Reset: Ctrl+D
Type 'help()' (without the quotes) then press ENTER.

>>> import this
The Zen of MicroPython, by Nicholas H.Tollervey

Code,
Hack it,
Less is more,
Keep it simple,
Small is beautiful,

Be brave! Break things! Learn and have fun!
Express yourself with MicroPython.

Happy hacking! :-)
>>>

BBC micro:bit MicroPython Editor

Typing all the Python commands directly into the shell can be a bit difficult. You can use a very nice and dedicated editor to write code and produce the compiled application for the micro:bit. All you need to do is clone this repository

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git clone [email protected]:ntoll/upyed.git

Open the file named editor.html with your browser and start writing your code. When your code is done, you can generate the .hex file clicking on Download button. To load the compiled application you just need to drag & drop the .hex file to the mounted device, exactly like you did the first time to flash it. If you need a reference for all the methods and libraries available, you can consult the official documentation here http://microbit-micropython.readthedocs.org/en/latest/index.html

References

• https://github.com/ntoll/microrepl
• https://github.com/ntoll/upyed
• https://www.microbit.co.uk/
• http://microbit-micropython.readthedocs.org/en/latest/index.html