Main Content

Unicast E1.31 to WS2811/WS2812 WiFi controller, output up to 1360 pixels (8 ports/universes, 170 pixels per port, 4080 channels).

I was looking for a relatively inexpensive way to drive a large number of WS2811/WS2812 LED Pixels from Vixen/Falcon Pi Player, for my Christmas light display. Most pre-built controllers I found are expensive and most diy versions are a single channel/universe per controller. So, I set out to code/build my own.

Hardware:
On the hardware side, the ESP8266 fit the price point well, and even though I wasn’t initially crazy about a wireless solution, I set out to see how many pixels I could get it to successfully drive. I settled on the Wemos D1 Mini Pro for the job. They can be purchased from Banggood, AliExpress, or Ebay for under $5 US.

With only a single usable TX port (the other for programming and debugging), needed for writing with the proper timing for the WS2811/WS2812 addressable pixels, I needed an inexpensive component that would be able to switch at very high speed to support multiplexing the data output across the output channels. The SN74HCT125N 4 channel buffer/driver chips offered the functionality perfect functionality and can be found on Ebay for around $0.50 US.

Last but not least, don’t forget the 10K ohm resistors. While it will probably work without these, the pixels may not completely latch when the driver disables the output. When this happens, the “Y” output port voltage can float, the resistance to ground will maintain the pixel led latch.”

Link to article