Since we first started carrying NeoPixels back in 2012, the chainable RGB LEDs have taken over the world. And a big part of that success is due to the simplicity of their wiring – just one data wire, no matter how many pixels you’ve got. So no surprise they’re everywhere, blinking away in art exhibits, maker faire demos, DJ booths, decorations, and costumes.
But, at some point, every NeoPixel’er bumps into the constraints of that single-data-wire: the timing is very picky and often time your code has to stop completely so that it can burst out the data without any interruptions. This requirement makes it tough to create fast-update lighting effects, and limits the number of pixels you can drive before other hardware peripherals get attention.
Resident pixel-pro Paint Your Dragon (who coined the name NeoPixel dont-cha-know!) took on this challenge and has succeeded gloriously. By carefully examining the ATSAMD51 datasheet he noticed you could use the Timer 0 in ‘waveform’ mode, and create 8 unique waveforms over DMA that would handle all the pixel-pushing for you.
Thus were born the NeoPXL8 Arduino library and NeoPXL8 FeatherWing! The library runs on our Feather M4 and handles all the NeoPixeling for you, up to 8 strands of concurrent DMA output each one can be 1750 RGB pixels long for a total of 8 x 1750 = 14000 pixels. That leaves you some RAM for your code to run in as well. Even though you could connect that many pixels, what we think this ‘Wing does best is take advantage of DMA + the SAMD51’s blazingly-fast 120MHz processor to manage animations for hundreds of pixels with ease
To make connection easy, this FeatherWing does the level-shifting and pin arrangements for you. All 8 strands have a level shifter that converts the 3.3V logic level to 5V logic, there’s a little switch-cap converter that generates the clean 5V power supply for you. Then a 100 ohm resistor in line after the buffer reduces ringing on long wiring runs.
You get two options for connecting NeoPixels:
2 x 8 Header with ground and 5V-logic signal, in pairs
2 x RJ-45 ‘Ethernet’ Jacks, with ground and 5V-logic signal per twisted pair. This matches the same wiring as the OctWS2811
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Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
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Python for Microcontrollers – Adafruit Daily — Python on Microcontrollers Newsletter: New Python Releases, an ESP32+MicroPython IDE and Much More! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi
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