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The PiGlow is a small add on board for the Raspberry Pi that provides 18 individually controllable LEDs.

Learn more:

This repository contains the library and examples for the PiGlow board.


Full install ( recommended ):

We've created a super-easy installation script that will install all pre-requisites and get your Piglow up and running in a jiffy. To run it fire up Terminal which you'll find in Menu -> Accessories -> Terminal on your Raspberry Pi desktop like so:

Finding the terminal

In the new terminal window, run our easy installer by typing:

curl -sS | bash

If you choose to download examples you'll find them in /home/pi/Pimoroni/piglow/.

Library install for Python 3:

on Raspbian:

sudo apt-get install python3-piglow

other environments:

sudo pip3 install piglow

Library install for Python 2:

on Raspbian:

sudo apt-get install python-piglow

other environments:

sudo pip2 install piglow

In all cases you will have to enable the i2c bus.

Documentation & Support

Backwards Compatibility

The PiGlow Python library is designed to support examples written for Jason's PiGlow library found here:

It's compatible with the examples, and we've ported some over to show you how it's done.

Using PiGlow

To use the piglow library, you'll probably want to start by importing it:

import piglow

Now, you can turn some LEDs on:

Nothing will happen yet, you've got to update PiGlow with your changes. Why? Because it's quicker! If you're setting up a pattern it costs time and resources to redraw every step of that setup to the PiGlow, so we don't do that. Instead you need to call show like so:

A bug is a feature you can't turn off, however, so if you want to change that behaviour you can set it after importing piglow:

piglow.auto_update = True

This will turn on auto update, refreshing the PiGlow after each change so you don't have to.

Function Reference


  • piglow.auto_update - Set to True or False, determines if the PiGlow should automatically update after each LED change
  • piglow.clear_on_exit - Set to True or False, determines if the PiGlow should be cleared on exit


  • piglow.white( value from 0 to 255 )
  • value from 0 to 255 )
  • value from 0 to 255 )
  • piglow.yellow( value from 0 to 255 )
  • value from 0 to 255 )
  • value from 0 to 255 )

Arm, Spoke, Leg, they're all the same thing!

piglow.arm( index from 0 to 2, value from 0 to 255 )

Multiple LEDs in various different ways

The set method accepts a list of LEDs, a list of values, or a single LED or value, or any permutation therein:

piglow.set(0, 255) - sets LED 0 to full brightness

piglow.set([1,3,5,7,9,11,13,15,17],255) - sets all odd LEDs to full brightness

piglow.set(0,[50,50,50]) - let the 3 LEDs starting at index 0 to 50 brightness

Other support for PiGlow

Gordon Henderson (@drogon on Twitter) has very kindly added support for PiGlow into his very popular wiringPi library and even includes a basic command line tool that you can use to control your PiGlow!

Simon Walters (@cymplecy) has added awesome PiGlow support to his Raspberry Pi GPIO Scratch library:

Jason Barnett has put together a great Python class and a load of samples:

Ben Lebherz has forked Jasons project and tidied up the code a bit while adding gamma correction:

Manuel Ernst has created a Node.js library:

More information

For more information the datasheet for the SN3218 IC is included in this repository which outlines the complete communication protocol for the chip.

For those wanting to wire up their PiGlow in other ways these are the GPIO pins used by the module:

  • P1 & P17 (3V3)
  • P2 (5V)
  • P14 (GND)
  • P3 (SDA)
  • P5 (SCL)

Special Thanks

A special thanks for Jason Barnett for carrying the PiGlow torch with his original library.