Download Adafruit_IS31FL3731 library

To begin reading sensor data, you will need to download Adafruit_IS31FL3731 from our github repository. You can do that by visiting the github repo and manually downloading or, easier, just click this button to download the zip

Rename the uncompressed folder Adafruit_IS31FL3731 and check that the Adafruit_IS31FL3731 folder contains Adafruit_IS31FL3731.cpp and Adafruit_IS31FL3731.h

Place the Adafruit_IS31FL3731 library folder your arduinosketchfolder/libraries/ folder.
You may need to create the libraries subfolder if its your first library. Restart the IDE.

We also have a great tutorial on Arduino library installation at:

Rename the uncompressed folder Adafruit_GFX and check that the Adafruit_GFX folder contains Adafruit_GFX.cpp and Adafruit_GFX.h

Place the Adafruit_GFX library folder your arduinosketchfolder/libraries/ folder like you did with the IS31FL library

Load Demo

Open up File->Examples->Adafruit_IS31FL3731->featherswirldemo and upload to your Feather + CharliePlex Matrix Feather

You must update the code before uploading!

At the top of the sketch, find the code that says

// If you're using the full breakout...
Adafruit_IS31FL3731 ledmatrix = Adafruit_IS31FL3731();
// If you're using the FeatherWing version
//Adafruit_IS31FL3731_Wing ledmatrix = Adafruit_IS31FL3731_Wing();

and uncomment the last line and recomment the second line so you have:

// If you're using the full breakout...
//Adafruit_IS31FL3731 ledmatrix = Adafruit_IS31FL3731();
// If you're using the FeatherWing version
Adafruit_IS31FL3731_Wing ledmatrix = Adafruit_IS31FL3731_Wing();

Upload to your Arduino, you'll see the LED display swirl different brightnesses!

This guide was first published on May 20, 2016. It was last updated on Nov 12, 2018. This page (Usage) was last updated on Sep 07, 2016.