Overview

Wouldn't it be fun to add bright, beautiful NeoPixels to your Raspberry Pi project? NeoPixels, and the WS2811/2812 LEDs that make them up, require a data signal with very specific timing to work correctly. Because the Raspberry Pi runs a multi-tasking Linux operating system it doesn't have real-time control over its GPIO pins and can't easily drive NeoPixels.  Typically a small microcontroller like a Trinket or Teensy can be used to communicate with the Raspberry Pi and generate the NeoPixel data signal. But you're in luck! Thanks to the Adafruit CircuitPython NeoPixel library, you can now control NeoPixels or WS2811/WS2812 LEDs directly from your Raspberry Pi!

The Adafruit CircuitPython NeoPixel library solves the real-time control problem by using the PWM and DMA hardware on the Raspberry Pi's processor.  The PWM (pulse-width modulation) module can generate a signal with a specific duty cycle, for example to drive a servo or dim an LED.  The DMA (direct memory access) module can transfer bytes of memory between parts of the processor without using the CPU.  By using DMA to send a specific sequence of bytes to the PWM module, the NeoPixel data signal can be generated without being interrupted by the Raspberry Pi's operating system.

The great thing about this library is that it does all the hard work of setting up PWM and DMA to drive NeoPixels.  You can use these LEDs with a single-board computer (like Raspberry Pi!) that has GPIO and Python thanks to Adafruit_Blinka, our CircuitPython-for-Python compatibility library.

Before you get started you will want to be familiar with how to connect to a Raspberry Pi's terminal using SSH.  It will also be helpful to check out the NeoPixel Uberguide for more information on using NeoPixels.

This guide was first published on Sep 12, 2014. It was last updated on Nov 20, 2018. This page (Overview) was last updated on Oct 23, 2018.