Adafruit CircuitPython API Reference¶
Welcome to the API reference documentation for Adafruit CircuitPython. This contains low-level API reference docs which may link out to separate “getting started” guides. Adafruit has many excellent tutorials available through the Adafruit Learning System.
CircuitPython is an education friendly open source derivative of MicroPython. CircuitPython supports use on educational development boards designed and sold by Adafruit. Adafruit CircuitPython features unified Python core APIs and a growing list of Adafruit libraries and drivers of that work with it.
This project is stable. Most APIs should be stable going forward. Those that change will change on major version numbers such as 2.0.0 and 3.0.0.
Designed for CircuitPython¶
See CONTRIBUTING.md for full guidelines but please be aware that by contributing to this project you are agreeing to the Code of Conduct. Contributors who follow the Code of Conduct are welcome to submit pull requests and they will be promptly reviewed by project admins. Please join the Gitter chat or Discord too.
Differences from MicroPython¶
- includes a port for Atmel SAMD21 (Commonly known as M0 in Adafruit product names.)
- supports only Atmel SAMD21 and ESP8266 ports.
- tracks MicroPython’s releases (not master).
- The order that files are run and the state that is shared between them. CircuitPython’s goal is to clarify the role of each file and make each file independent from each other.
settings.py) runs only once on start up before USB is initialized. This lays the ground work for configuring USB at startup rather than it being fixed. Since serial is not available, output is written to
main.py) is run after every reload until it finishes or is interrupted. After it is done running, the vm and hardware is reinitialized. This means you cannot read state from ``code.py`` in the REPL anymore. CircuitPython’s goal for this change includes reduce confusion about pins and memory being used.
code.pythe REPL can be entered by pressing any key. It no longer shares state with
code.pyso it is a fresh vm.
- Autoreload state will be maintained across reload.
- Adds a safe mode that does not run user code after a hard crash or brown out. The hope is that this will make it easier to fix code that causes nasty crashes by making it available through mass storage after the crash. A reset (the button) is needed after its fixed to get back into normal mode.
- No module aliasing. (
utimeare not available as
randomare CPython compatible.
storagemodule which manages file system mounts. (Functionality from
- Modules with a CPython counterpart, such as
random, are strict subsets of their CPython version. Therefore, code from CircuitPython is runnable on CPython but not necessarily the reverse.
- tick count is available as time.monotonic()
- RGB status LED
- Auto-reload after file write over mass storage. (Disable with
- Wait state after boot and main run, before REPL.
- Main is one of these:
- Boot is one of these:
Here is an overview of the top-level source code directories.
The core code of MicroPython is shared amongst ports including CircuitPython:
docsHigh level user documentation in Sphinx reStructuredText format.
driversExternal device drivers written in Python.
examplesA few example Python scripts.
extmodShared C code used in multiple ports’ modules.
libShared core C code including externally developed libraries such as FATFS.
logoThe MicroPython logo.
mpy-crossA cross compiler that converts Python files to byte code prior to being run in MicroPython. Useful for reducing library size.
pyCore Python implementation, including compiler, runtime, and core library.
shared-bindingsShared definition of Python modules, their docs and backing C APIs. Ports must implement the C API to support the corresponding module.
shared-moduleShared implementation of Python modules that may be based on
testsTest framework and test scripts.
toolsVarious tools, including the pyboard.py module.
Ports include the code unique to a microcontroller line and also variations based on the board.
atmel-samdSupport for SAMD21 based boards such as Arduino Zero, Adafruit Feather M0 Basic, and Adafruit Feather M0 Bluefruit LE.
bare-armA bare minimum version of MicroPython for ARM MCUs.
cc3200Support for boards based CC3200 from TI such as the WiPy 1.0.
esp8266Support for boards based on ESP8266 WiFi modules such as the Adafruit Feather HUZZAH.
minimalA minimal MicroPython port. Start with this if you want to port MicroPython to another microcontroller.
pic16bitSupport for 16-bit PIC microcontrollers.
qemu-armSupport for ARM emulation through QEMU.
stmhalSupport for boards based on STM32 microcontrollers including the MicroPython flagship PyBoard.
teensySupport for the Teensy line of boards such as the Teensy 3.1.
unixSupport for UNIX.
windowsSupport for Windows.
zephyrSupport for Zephyr, a real-time operating system by the Linux Foundation.
CircuitPython only maintains the
The rest are here to maintain compatibility with the
Full Table of Contents¶
- Core Modules
- Support Matrix
_stage--- C-level helpers for animation of sprites on a stage
analogio--- Analog hardware support
audiobusio--- Support for audio input and output over digital bus
audioio--- Support for audio input and output
bitbangio--- Digital protocols implemented by the CPU
board--- Board specific pin names
busio--- Hardware accelerated behavior
digitalio--- Basic digital pin support
gamepad--- Button handling
microcontroller--- Pin references and cpu functionality
multiterminal--- Manage additional terminal sources
neopixel_write--- Low-level neopixel implementation
nvm--- Non-volatile memory
os--- functions that an OS normally provides
pulseio--- Support for pulse based protocols
random--- psuedo-random numbers and choices
storage--- storage management
time--- time and timing related functions
touchio--- Touch related IO
uheap--- Heap size analysis
usb_hid--- USB Human Interface Device
ustack--- Stack information and analysis
help()- Built-in method to provide helpful information
- Supported Ports
- Additional Adafruit Libraries and Drivers on GitHub
- Foundational Libraries
- Helper Libraries
- RGB Displays
- SD Card
- Analog-to-digital converters: ADS1015 and ADS1115
- DS3231 Real-time Clock (Precision RTC)
- DS1307 Real-time Clock (5V RTC Breakout)
- PCF8523 Real-time Clock (Adalogger RTC)
- TCS34725 Color Sensor
- TSL2561 Light Sensor
- PCA9685 Motor and Servo Controllers
- HT16K33 LED Matrices and Segment Displays
- IS31FL3731 Charlieplexed LED Matrix
- MAX7219 LED Matrix