September 13, 2021

Web Server-Enabled LED Matrix

from hackster.io

The widespread availability of addressable LEDs has enabled makers to create colorful displays, which would have been difficult or impossible not too long ago.

Generally this requires programming in images beforehand, or creating a system that reacts programmatically to set inputs (e.g. a scoreboard or gauge). Brocki's LED-Matrix With Web Server does things a little differently, producing a local webpage that enables people to draw pixelated images over Wi-Fi.

It uses a series of 16 WS2815 LED strips, with 16 LEDs each, to display images as a 256 pixel matrix. This give it just the right amount of detail for a nice old-school feel. The grid and enclosure are laser cut, with a diffuser made out of frosted acrylic, carefully distanced from the LEDs for the proper effect.

The matrix display is based on a NodeMCU ESP8266 module for control, which generates the interface page. It also features an SD card reader for storage. Notably, WS2815 LEDs are used for the build, as opposed to the more commonly available WS2812Bs.

Unlike the '812Bs, the WS2815s work with 12V power, allowing for proper operation with lower current requirements. This meant utilizing a buck converter to supply the proper voltage to the NodeMCU, which seems like a reasonable tradeoff for being able to use a higher voltage for the LEDs.