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Topic: My library for the Microchip MCP23017 and MCP23018 I2C I/O expander ICs (Read 641 times) previous topic - next topic

OldBikerPete

Attached is my Arduino library for the Microchip MCP23017 and MCP23018 I/O expander chip. It uses the Arduino Wire library and was developed on a WeMOS D1 mini.
NOT FULLY TESTED.
The input and interrupt facilities have not been tested but the output has been tested and works.
This chip has three addressing pins, so up to eight chips can be chained on an I2C bus for 128 bits of programmable I/O.
By means of uncommenting and/or changing #defined values, the library can be compiled to be as small as possible with support for output on one chip only and no interrupt support, or can be compiled to support all 8 chips with full interrupt support and a callback function for interrupt support on each individual pin.

GaryP

Hi fellow biker!

This is interesting, I just found this topic when I was wondering how to expand my Wemos mini.
I twill try your library today, just woul dbe nice to know if you have done any modifications? It's been
a while since that post. Thanks!
 :)

Cheers,
Kari

The only law for me; Ohms Law: U=R*I       P=U*I
Note to self: "Damn! Why don't you just fix it!!!"

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