# Adafruit CircuitPython [![Build Status](https://travis-ci.org/adafruit/circuitpython.svg?branch=master)](https://travis-ci.org/adafruit/circuitpython) [![Doc Status](https://readthedocs.org/projects/circuitpython/badge/?version=latest)](http://circuitpython.readthedocs.io/) [![Gitter](https://badges.gitter.im/adafruit/circuitpython.svg)](https://gitter.im/adafruit/circuitpython?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge) This is an open source derivative of [MicroPython](http://www.micropython.org) for use on educational development boards designed and sold by [Adafruit](https://www.adafruit.com) including the [Arduino Zero](https://www.arduino.cc/en/Main/ArduinoBoardZero), [Adafruit Feather M0 Basic](https://www.adafruit.com/products/2772), [Adafruit Feather HUZZAH](https://www.adafruit.com/products/2821) and [Adafruit Feather M0 Bluefruit LE](https://www.adafruit.com/products/2995). As a MicroPython derivative, this implements Python 3.x on microcontrollers such as the SAMD21 and ESP8266. ## Project Status This project is in beta. Most APIs should be stable going forward. ## Documentation Guides and videos are available through the [Adafruit Learning System](https://learn.adafruit.com/) under the [CircuitPython category](https://learn.adafruit.com/category/circuitpython) and [MicroPython category](https://learn.adafruit.com/category/micropython). An API reference is also available on [Read the Docs](http://circuitpython.readthedocs.io/en/latest/?). ## Contributing See [CONTRIBUTING.md](https://github.com/adafruit/circuitpython/blob/master/CONTRIBUTING.md) for full guidelines but please be aware that by contributing to this project you are agreeing to the [Code of Conduct](https://github.com/adafruit/circuitpython/blob/master/CODE_OF_CONDUCT.md). Contributors who follow the [Code of Conduct](https://github.com/adafruit/circuitpython/blob/master/CODE_OF_CONDUCT.md) are welcome to submit pull requests and they will be promptly reviewed by project admins. Please join the [Gitter chat](https://gitter.im/adafruit/circuitpython) too. ## Differences from [MicroPython](https://github.com/micropython/micropython) * Port for Atmel SAMD21 (Commonly known as M0 in product names.) * No `machine` API on Atmel SAMD21 port. * Only supports Atmel SAMD21 and ESP8266 ports. * Unified hardware API: [`nativeio`](https://circuitpython.readthedocs.io/en/latest/shared-bindings/nativeio/__init__.html), [`microcontroller`](https://circuitpython.readthedocs.io/en/latest/shared-bindings/microcontroller/__init__.html), [`board`](https://circuitpython.readthedocs.io/en/latest/shared-bindings/board/__init__.html), [`bitbangio`](https://circuitpython.readthedocs.io/en/latest/shared-bindings/bitbangio/__init__.html) (Only available on atmel-samd21 and ESP8266 currently.) * Tracks MicroPython's releases (not master). * No module aliasing. (`uos` and `utime` are not available as `os` and `time` respectively.) * Modules with a CPython counterpart, such as `time`, are strict [subsets](https://circuitpython.readthedocs.io/en/latest/shared-bindings/time/__init__.html) of their [CPython version](https://docs.python.org/3.4/library/time.html?highlight=time#module-time). Therefore, code from CircuitPython is runnable on CPython but not necessarily the reverse. * tick count is available as [`time.monotonic()`](https://circuitpython.readthedocs.io/en/latest/shared-bindings/time/__init__.html#time.monotonic) * `os` only available as `uos` * atmel-samd21 features * RGB status LED * Auto-reset after file write over mass storage. (Disable with `samd.disable_autoreset()`) * Wait state after boot and main run, before REPL. * Main is one of these: code.txt, code.py, main.py, main.txt * Boot is one of these: settings.txt, settings.py, boot.py, boot.txt ## Project Structure Here is an overview of the top-level directories. ### Core The core code of MicroPython is shared amongst ports including CircuitPython: - `docs` High level user documentation in Sphinx reStructuredText format. - `drivers` External device drivers written in Python. - `examples` A few example Python scripts. - `extmod` Shared C code used in multiple ports' modules. - `lib` Shared core C code including externally developed libraries such as FATFS. - `logo` The MicroPython logo. - `mpy-cross` A cross compiler that converts Python files to byte code prior to being run in MicroPython. Useful for reducing library size. - `py` Core Python implementation, including compiler, runtime, and core library. - `shared-bindings` Shared definition of Python modules, their docs and backing C APIs. Ports must implement the C API to support the corresponding module. - `tests` Test framework and test scripts. - `tools` Various tools, including the pyboard.py module. ### Ports Ports include the code unique to a microcontroller line and also variations based on the board. - `atmel-samd` Support for SAMD21 based boards such as [Arduino Zero](https://www.arduino.cc/en/Main/ArduinoBoardZero), [Adafruit Feather M0 Basic](https://www.adafruit.com/products/2772), and [Adafruit Feather M0 Bluefruit LE](https://www.adafruit.com/products/2995). - `bare-arm` A bare minimum version of MicroPython for ARM MCUs. - `cc3200` Support for boards based [CC3200](http://www.ti.com/product/CC3200) from TI such as the [WiPy 1.0](https://www.pycom.io/solutions/py-boards/wipy1/). - `esp8266` Support for boards based on ESP8266 WiFi modules such as the [Adafruit Feather HUZZAH](https://www.adafruit.com/products/2821). - `minimal` A minimal MicroPython port. Start with this if you want to port MicroPython to another microcontroller. - `pic16bit` Support for 16-bit PIC microcontrollers. - `qemu-arm` Support for ARM emulation through [QEMU](https://qemu.org). - `stmhal` Support for boards based on STM32 microcontrollers including the MicroPython flagship [PyBoard](https://store.micropython.org/store/#/products/PYBv1_1). - `teensy` Support for the Teensy line of boards such as the [Teensy 3.1](https://www.pjrc.com/teensy/teensy31.html). - `unix` Support for UNIX. - `windows` Support for [Windows](https://www.microsoft.com/en-us/windows/). - `zephyr` Support for [Zephyr](https://www.zephyrproject.org/), a real-time operating system by the Linux Foundation. CircuitPython only maintains the `atmel-samd` and `esp8266` ports. The rest are here to maintain compatibility with the [MicroPython](https://github.com/micropython/micropython) parent project.