Posted by

ITEM TILE – File Size: 3.1K

MicroPython – a lean and efficient Python implementation for microcontrollers and constrained systems

Build Status Coverage Status

The MicroPython project

MicroPython Logo

This is the MicroPython project, which aims to put an implementationof Python 3.x on microcontrollers and small embedded systems.You can find the official website at

WARNING: this project is in beta stage and is subject to changes of thecode-base, including project-wide name changes and API changes.

MicroPython implements the entire Python 3.4 syntax (including exceptions,with, yield from, etc., and additionally async/await keywords fromPython 3.5). The following core datatypes are provided: str (includingbasic Unicode support), bytes, bytearray, tuple, list, dict, set,frozenset, array.array, collections.namedtuple, classes and instances.Builtin modules include sys, time, and struct, etc. Select ports havesupport for _thread module (multithreading). Note that only a subset ofPython 3 functionality is implemented for the data types and modules.

MicroPython can execute scripts in textual source form or from precompiledbytecode, in both cases either from an on-device filesystem or “frozen” intothe MicroPython executable.

See the repository for the MicroPythonboard (PyBoard), the officially supported reference electronic circuit board.

Major components in this repository:- py/ — the core Python implementation, including compiler, runtime, and core library.- mpy-cross/ — the MicroPython cross-compiler which is used to turn scripts into precompiled bytecode.- ports/unix/ — a version of MicroPython that runs on Unix.- ports/stm32/ — a version of MicroPython that runs on the PyBoard and similar STM32 boards (using ST’s Cube HAL drivers).- ports/minimal/ — a minimal MicroPython port. Start with this if you want to port MicroPython to another microcontroller.- tests/ — test framework and test scripts.- docs/ — user documentation in Sphinx reStructuredText format. Rendered HTML documentation is available at

Additional components:- ports/bare-arm/ — a bare minimum version of MicroPython for ARM MCUs. Used mostly to control code size.- ports/teensy/ — a version of MicroPython that runs on the Teensy 3.1 (preliminary but functional).- ports/pic16bit/ — a version of MicroPython for 16-bit PIC microcontrollers.- ports/cc3200/ — a version of MicroPython that runs on the CC3200 from TI.- ports/esp8266/ — a version of MicroPython that runs on Espressif’s ESP8266 SoC.- ports/esp32/ — a version of MicroPython that runs on Espressif’s ESP32 SoC.- ports/nrf/ — a version of MicroPython that runs on Nordic’s nRF51 and nRF52 MCUs.- extmod/ — additional (non-core) modules implemented in C.- tools/ — various tools, including the module.- examples/ — a few example Python scripts.

The subdirectories above may include READMEs with additional info.

“make” is used to build the components, or “gmake” on BSD-based systems.You will also need bash, gcc, and Python 3.3+ available as the command python3(if your system only has Python 2.7 then invoke make with the additional optionPYTHON=python2).

The MicroPython cross-compiler, mpy-cross

Most ports require the MicroPython cross-compiler to be built first. Thisprogram, called mpy-cross, is used to pre-compile Python scripts to .mpyfiles which can then be included (frozen) into the firmware/executable fora port. To build mpy-cross use:

$ cd mpy-cross$ make

The Unix version

The “unix” port requires a standard Unix environment with gcc and GNU make.x86 and x64 architectures are supported (i.e. x86 32- and 64-bit), as wellas ARM and MIPS. Making full-featured port to another architecture requireswriting some assembly code for the exception handling and garbage collection.Alternatively, fallback implementation based on setjmp/longjmp can be used.

To build (see section below for required dependencies):

$ cd ports/unix$ make submodules$ make

Then to give it a try:

$ ./micropython>>> list(5 * x + y for x in range(10) for y in [4, 2, 1])

Use CTRL-D (i.e. EOF) to exit the shell.Learn about command-line options (in particular, how to increase heap sizewhich may be needed for larger applications):

$ ./micropython --help

Run complete testsuite:

$ make test

Unix version comes with a builtin package manager called upip, e.g.:

$ ./micropython -m upip install micropython-pystone$ ./micropython -m pystone

Browse available modules onPyPI.Standard library modules come frommicropython-lib project.

External dependencies

Building MicroPython ports may require some dependencies installed.

For Unix port, libffi library and pkg-config tool are required. OnDebian/Ubuntu/Mint derivative Linux distros, install build-essential(includes toolchain and make), libffi-dev, and pkg-config packages.

Other dependencies can be built together with MicroPython. This maybe required to enable extra features or capabilities, and in recentversions of MicroPython, these may be enabled by default. To buildthese additional dependencies, in the port directory you’reinterested in (e.g. ports/unix/) first execute:

$ make submodules

This will fetch all the relevant git submodules (sub repositories) thatthe port needs. Use the same command to get the latest versions ofsubmodules as they are updated from time to time. After that execute:

$ make deplibs

This will build all available dependencies (regardless whether theyare used or not). If you intend to build MicroPython with additionaloptions (like cross-compiling), the same set of options should be passedto make deplibs. To actually enable/disable use of dependencies, editports/unix/ file, which has inline descriptions of the options.For example, to build SSL module (required for upip tool described above,and so enabled by dfeault), MICROPY_PY_USSL should be set to 1.

For some ports, building required dependences is transparent, and happensautomatically. But they still need to be fetched with the make submodulescommand.

The STM32 version

The “stm32” port requires an ARM compiler, arm-none-eabi-gcc, and associatedbin-utils. For those using Arch Linux, you need arm-none-eabi-binutils,arm-none-eabi-gcc and arm-none-eabi-newlib packages. Otherwise, try here:

To build:

$ cd ports/stm32$ make submodules$ make

You then need to get your board into DFU mode. On the pyboard, connect the3V3 pin to the P1/DFU pin with a wire (on PYBv1.0 they are next to each otheron the bottom left of the board, second row from the bottom).

Then to flash the code via USB DFU to your device:

$ make deploy

This will use the included tools/ script. If flashing the firmwaredoes not work it may be because you don’t have the correct permissions, andneed to use sudo make deploy.See the file in the ports/stm32/ directory for further details.


MicroPython is an open-source project and welcomes contributions. To beproductive, please be sure to follow theContributors’ Guidelinesand the Code Conventions.Note that MicroPython is licenced under the MIT license, and all contributionsshould follow this license.

To restore the repository download the bundle


and run:

 git clone micropython-micropython_-_2019-11-29_04-32-01.bundle 

Uploader: micropython
Upload date: 2019-11-29