How to minify your MicroPython scripts and use a custom runtime on the BBC micro:bit

Being small is one of the strengths of the BBC micro:bit. However, small also applies to the amount of storage space on the device which can be problematic if you have MicroPython scripts that are simply too long to fit onto the micro:bit.

Happily, there is a way to “minify” (remove the comments and compress the white-space in your source code) so that the program remains unchanged but the source code takes up less room.

Sometimes, if you’re an advanced user, you want to try out a version of the MicroPython runtime for the micro:bit that’s different to the one already included in Mu.

Happily there’s a way to tell Mu which runtime .hex file to use instead of the default.

Such settings for the micro:bit are found in the “Mu Administration” dialog which you can see by clicking on the “cog” icon in the bottom right hand corner of Mu’s window (highlighted in red in the image below).

As shown below, select the “BBC micro:bit Settings” tab and toggle the “minify” checkbox to switch minification on or off. Use the text box to enter the full path to the custom MicroPython runtime.