Introduction¶

An embedded library for Python to control LEDs. It uses a non-blocking approach and can control LEDs in simple (on/off) and complex (blinking, breathing and more) ways in a time-driven manner.

This is a pure Python port of my JLed C++ library.

Features¶

non-blocking
effects: simple on/off, breathe, blink, candle, fade, user-defined
supports inverted polarity of LED
easy configuration using fluent interface
can control groups of LEDs sequentially or in parallel
supports CircuitPython and MicroPython

Usage Example¶

Test JLed interactively in a CircuitPython REPL:

Adafruit CircuitPython 7.3.3 on 2022-08-29; Raspberry Pi Pico with rp2040
>>> import board
>>> from jled import JLed
>>> led=JLed(board.LED).breathe(500).delay_after(250).repeat(5)
>>> while led.update(): pass

This creates a JLed object connected to the builtin LED (board.LED), with a breathe effect that is repeated 5 times. Each iteration is followed by a delay of 250 ms, before starting again. By calling led.update() periodically, the LED gets physically updated. Alternatively play(led) can be call in the REPL as a shortcut. Once finished, call led.reset() before playing the effect again.

Cheat Sheet¶

Installation¶

On supported GNU/Linux systems like the Raspberry Pi (with Adafruit-Blinka), you can install the lib locally from PyPI. To install for current user:

pip3 install circuitpython-jled

To install system-wide (this may be required in some cases):

sudo pip3 install circuitpython-jled

To install in a virtual environment in your current project:

mkdir project-name && cd project-name
python3 -m venv .venv
source .env/bin/activate
pip3 install circuitpython-jled

Installing to a Connected CircuitPython Device with Circup¶

JLed is available in the Circuitpython Community Bundle and can easily installed with circup by running:

$ circup install jled

Optionally copy also one of the example as code.py to the root of the filesystem.

Installing on a MicroPython device¶

Create a directory called jled on the device and copy the following files into this directory: into this directory: jled.py, jled_sequence.py hal_pwm_micropython.py, hal_time_micropython.py, play.py, __init__.py`. Optionally also copy one of the example as main.py to the root of the filesystem. The overall structure is:

/
├─ main.py
└─ jled
    ├─ __init__.[m]py
    ├─ hal_pwm_micropython.[m]py
    ├─ hal_time_micropython.[m]py
    ├─ jled.[m]py
    ├─ jled_sequence.[m]py
    └─ play.[m]py

To reduce memory consumption, Python source files can be compiled to binary mpy format using the mpy-cross tool. For convenience, a script to compile and copy jled to a connected device is provided here (see scripts/install_mp.sh).

Documentation¶

API documentation for this library can be found on here.

Rebuild the documentation with sphinx-build -E -W -b html . _build/html in the docs directory. Run pip install ".[optional]" before to install build-time dependency Sphinx

Tests¶

Unit tests (using https://docs.pytest.org) are provided, run the tests with:

$ pip install ".[optional]"
$ pytest

To run the pre-commit-hook locally, run pre-commit run --all-files

Author & Copyright¶

Table of Contents¶

Examples