Introduction

CircuitPython helper library for gpio expanders (Texas Instrument PCA95xx and TCA95xx chips).

Dependencies

This driver depends on:

• Adafruit CircuitPython

• Bus Device

• Register

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 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 gpio_expander

Or the following command to update an existing version:

circup update

Usage Example

import board

from gpio_expander import PCA9555, PCA9534

#######################
# 16 bit I2C expander #
#######################
_pca9555 = PCA9555(board.I2C(), 0x20)

# print input 0 bit 0 value; datasheet bit field's name has underscore in place of dot for 16 bit expander
print(_pca9555.I0_0)

# configure an output port and set its value
_pca9555.C1_3 = 0
_pca9555.O1_3 = 0

# print entire configuration registry
print(_pca9555.configuration_ports)

Documentation

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

For information on building library documentation, please check out this guide.

Contributing

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