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Help for Mu

Mu is a simple code editor for beginner programmers. It's written in Python and works on Windows, OSX, Linux and Raspberry Pi.


Starting Mu

Coming soon… ;-)

Mu Buttons


new button

Click the new button to start in a new file in mu. This won’t damage your old files - a fresh place to work.


load button

Load a file - your old work or some other python file to work on.


save button

Saves your work so you can keep it for later and not loose it if you loose power. Do this often!


flash button

Flash your code onto the Microbit. This is how you get your code to run!


files button

Show the files on your Micropython.


repl button

The repl is a way of typing stuff and seeing the microbit do something immediately. It is an abbreviation for “read-eval-print-loop”.

Zoom In

Zoom in button

Make the letters bigger

Zoom Out

Zoom out button

Make the letters smaller


Check Code button

This button will check your code and underline errors you have made. Worth doing before you flash your code.


Help Button

Show help - should be this help.


Quit Button

Press this when you are done with Mu. Mu will make sure you’ve saved your work if you want to keep it.

Advanced - settings file

Workspace settings are stored in a file named settings.json.

By default this file is located in the application data directory, but a settings file in the same directory as the Mu application itself will take priority.

By default, Mu uses a bundled version of the MicroPython runtime, but advanced users (e.g. those developing the Microbit runtime) can use the settings.json file to configure Mu to use their own runtime hex file.

To do this, add a line like this to the settings.json file:

“microbit_runtime_hex”: “customhex.hex”

If the file name is not fully qualified then it will be searched for in the workspace directory.

Microbit Help

Microbit Micropython Help