The MicroPython project

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

WARNING: this project is in beta stage and is subject to changes of the code-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" keyword from Python 3.5). The following core datatypes are provided: str (including basic 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 have support for _thread module (multithreading). Note that only subset of Python 3.4 functionality implemented for the data types and modules.

See the repository www.github.com/micropython/pyboard for the MicroPython board (PyBoard), the officially supported reference electronic circuit board.

The following components are actively maintained by Pycom:

• py/ -- the core Python implementation, including compiler, runtime, and core library.
• exp32/ -- a version of MicroPython that runs on the ESP32 based boards from Pycom.
• tests/ -- test framework and test scripts.

Additional components:

• stmhal/ -- a version of MicroPython that runs on the PyBoard and similar STM32 boards (using ST's Cube HAL drivers).
• minimal/ -- a minimal MicroPython port. Start with this if you want to port MicroPython to another microcontroller.
• bare-arm/ -- a bare minimum version of MicroPython for ARM MCUs. Used mostly to control code size.
• teensy/ -- a version of MicroPython that runs on the Teensy 3.1 (preliminary but functional).
• pic16bit/ -- a version of MicroPython for 16-bit PIC microcontrollers.
• cc3200/ -- a version of MicroPython that runs on the CC3200 from TI.
• esp8266/ -- an experimental port for ESP8266 WiFi modules.
• tools/ -- various tools, including the pyboard.py module.
• examples/ -- a few example Python scripts.
• docs/ -- user documentation in Sphinx reStructuredText format.

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 and Python (at least 2.7 or 3.3).

The ESP32 version

The "esp32" port requires an xtensa gcc compiler, which can be downloaded from the Espressif website:

• for 64-bit Linux::

  https://dl.espressif.com/dl/xtensa-esp32-elf-linux64-1.22.0-80-g6c4433a-5.2.0.tar.gz

• for 32-bit Linux::

  https://dl.espressif.com/dl/xtensa-esp32-elf-linux32-1.22.0-80-g6c4433a-5.2.0.tar.gz

• for Mac OS:

  https://dl.espressif.com/dl/xtensa-esp32-elf-osx-1.22.0-80-g6c4433a-5.2.0.tar.gz

To use it, you will need to update your PATH environment variable in ~/.bash_profile file. To make xtensa-esp32-elf available for all terminal sessions, add the following line to your ~/.bash_profile file::

export PATH=$PATH:$HOME/esp/xtensa-esp32-elf/bin

Alternatively, you may create an alias for the above command. This way you can get the toolchain only when you need it. To do this, add different line to your ~/.bash_profile file::

alias get_esp32="export PATH=$PATH:$HOME/esp/xtensa-esp32-elf/bin"

Then when you need the toolchain you can type get_esp32 on the command line and the toolchain will be added to your PATH.

You also need the ESP IDF along side this repository in order to build the ESP32 port. To get it:

$ git clone https://github.com/pycom/pycom-esp-idf.git

After cloning, make sure to checkout all the submodules:

$ cd pycom-esp-idf
$ git submodule update --init

Finally, before building, export the IDF_PATH variable

$ export IDF_PATH=~/pycom-esp-idf

Prior to building the main firmware, you need to build mpy-cross

$ cd mpy-cross && make clean && make && cd ..

By default the firmware is built for the WIPY2:

$ cd esp32
$ make clean
$ make TARGET=boot
$ make TARGET=app
$ make flash

You can change the board type by using the BOARD variable:

$ cd esp32
$ make BOARD=GPY clean
$ make BOARD=GPY TARGET=boot
$ make BOARD=GPY TARGET=app
$ make BOARD=GPY flash

We currently support the following BOARD types:

WIPY LOPY SIPY GPY FIPY LOPY4

For LoRa, you may need to specify the LORA_BAND as explained below.

To specify a serial port other than /dev/ttyUSB0, use ESPPORT variable:

$ # On MacOS
$ make ESPPORT=/dev/tty.usbserial-DQ008HQY flash
$ # On Windows
$ make ESPPORT=COM3 flash
$ # On linux
$ # make ESPPORT=/dev/ttyUSB1 flash

To flash at full speed, use ESPSPEED variable:

$ make ESPSPEED=921600 flash

To build and flash a LoPy:

$ cd esp32
$ make BOARD=LOPY clean
$ make BOARD=LOPY TARGET=boot
$ make BOARD=LOPY TARGET=app
$ make BOARD=LOPY flash

The above also applies to the FiPy and LoPy4

Make sure that your board is placed into programming mode, otherwise flashing will fail.
PyTrack and PySense boards will automatically switch into programming mode (currently supported on MacOS and Linux only!)
Expansion Board 2.0 users, please connect P2 to GND and then reset the board.