Adafruit MCP23008 library

Arduino Library for the MCP23008 (and '9) I2C I/O expander


Keywords
signal, input, output
Install
platformio lib install 517

Documentation

Adafruit MCP23008 Library Build StatusDocumentation

To download, click "Download Source" in the top right corner. Then install as indicated in our tutorial: --> http://www.ladyada.net/library/arduino/libraries.html in a folder called Adafruit_MCP23008.

You will also need the Adafruit BusIO library: https://github.com/adafruit/Adafruit_BusIO

This is very much beta, it seems to work fine but its not optimized and doesn't currently suport the interrupt capability of the chip

Currently it can do: setting pin directions, inputs and outputs and turning on/off the pull-up resistors

To use: Connect pin #1 of the expander to Analog 5 (i2c clock) Connect pin #2 of the expander to Analog 4 (i2c data) Connect pins #3, 4 and 5 of the expander to ground (address selection) Connect pin #6 and 18 of the expander to 5V (power and reset disable) Connect pin #9 of the expander to ground (common ground) Pins 10 thru 17 are your input/output pins

Check the datasheet for more info: http://ww1.microchip.com/downloads/en/DeviceDoc/21919b.pdf

Enjoy and send pull requests!