Introduction

CircuitPython helper library for the NXP 16-Channel I²C-Bus Constant-Current LED Driver

Dependencies

This driver depends on:

Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle or individual libraries can be installed using circup.

Installing from PyPI

Note

This library is not available on PyPI yet. Install documentation is included as a standard element. Stay tuned for PyPI availability!

On supported GNU/Linux systems like the Raspberry Pi, you can install the driver locally from PyPI. To install for current user:

pip3 install circuitpython-pca9955b

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

sudo pip3 install circuitpython-pca9955b

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-pca9955b

Installing to a Connected CircuitPython Device with Circup

Make sure that you have circup installed in your Python environment. Install it with the following command if necessary:

pip3 install circup

With circup installed and your CircuitPython device connected use the following command to install:

circup install pca9955b

Or the following command to update an existing version:

circup update

Usage Example

import time
import board
import busio

from pca9955b import PCA9955, LedChannel
i2c = busio.I2C(board.SCL, board.SDA)

ledDriver = PCA9955(i2c, address=0x3F, oe_pin=board.GP10, reset_pin=board.GP11)
ledDriver.reset()
ledDriver.output_enable = True

ledDriver.gain = 0xFF
ledDriver.brightness = 0x7F  # 50% brightness

ledDriver.channels[0].state = LedChannel.ON
time.sleep(5)
ledDriver.channels[0].state = LedChannel.OFF
time.sleep(5)

ledDriver.channels[0].state = LedChannel.PWM
for i in range(255):
    ledDriver.channels[0].brightness = i
    time.sleep(0.02)

Documentation

Class Diagram for library

API documentation for this library can be found on Read the Docs.

Contributing

Contributions are welcome! Please read our Code of Conduct before contributing to help this project stay welcoming.

Table of Contents

Examples

API Reference

API Reference