This project requires CircuitPython 6.2.0 or later, including beta releases 6.2.0-beta.3 and later.

The new RP2040 microcontroller from Raspberry Pi Foundation has a powerful feature: the PIO module, a sort of accelerated I/O processor.

In this guide, you will learn how you can use CircuitPython and PIO together to drive 8 separate NeoPixel LED strands using just 3 GPIO pins and a 74HC595 Shift Register.

One advantage of driving your NeoPixel LEDs this way is that less time is spent actually sending the pixel data to the LEDs—It is about 7.5x faster to show() your NeoPixels with the parallel method. Depending on your project, having parallel strips as opposed to chained strips can also make for better wiring.

Mostly, this guide is just a cool way to show off some of the capabilities of PIO itself.

Benchmark

The numbers below compare the speed of the two methods of refreshing NeoPixels, the traditional with a single 960-pixel chain, or 8 independent 120-pixel strands thanks to using PIO. It excludes the time to actually update animations on the strips, so it is a "best case" scenario.

Download: file
960 pixels, 100 refreshes
Neopixel show():  34.1 FPS,  32757 pixels/second
NeoPIO   show(): 232.7 FPS, 223418 pixels/second

Check out the following pages to learn more about PIO and how to use it in CircuitPython.

Parts

The Raspberry Pi foundation changed single-board computing when they released the Raspberry Pi computer, now they're ready to...
Out of Stock
The Raspberry Pi foundation changed single-board computing when they released the Raspberry Pi computer, now they're...
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Plug in and glow, this Adafruit NeoPixel LED Strip with JST PH Connector has 30 total LEDs in a "60 LED per meter" spacing,...
$12.50
In Stock

You can make this project with anywhere from 2 to 8 NeoPixel LED strands. Each strand should be the same length.

Add lots more outputs to a microcontroller system with chainable shift registers. These chips take a serial input (SPI) of 1 byte (8 bits) and then output those digital bits onto 8...
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This is a FCC/CE certified and UL listed power supply. Need a lot of 5V power? This switching supply gives a clean regulated 5V output at up to 2000mA. 110 or 240 input, so it works in...
$7.95
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Handy for making wire harnesses or jumpering between headers on PCB's. These premium jumper wires are 3" (75mm) long and come in a 'strip' of 40 (4 pieces of each of ten rainbow...
$3.95
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If you need to connect a DC power wall wart to a board that doesn't have a DC jack - this adapter will come in very handy! There is a 2.1mm DC jack on one end, and a screw terminal...
$2.00
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This guide was first published on Feb 23, 2021. It was last updated on 2021-02-23 12:32:27 -0500.

This page (Overview) was last updated on Feb 23, 2021.

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