This guide was first published on Jul 29, 2012. It was last
updated on Jul 29, 2012.
This page (Overview) was last updated on Apr 22, 2019.
RGB Pixels are digitally-controllable lights you can set to any color, or animate. Each pixel contains four RGB LEDs and a controller chip in a sturdy metal housing. The pixel is then 'flooded' with epoxy to make it waterproof. These are fairly large pixels but they have a lot of nice mounting options, such as two metal flanges on the side and a 0.15"/4mm diameter hole in the middle so you can screw them directly onto a surface. They're typically used to make outdoor signs. Compared to our other LED dots, these are much bigger and much brighter, good for larger scale installations.
At 12 volts, they draw a maximum of 120 milliamps per pixel: 40 mA each for red, green and blue.
The LED pixels are spaced along a strand of ribbon cable, with about 3 inches (75mm) between pixels. If additional distance is needed you can cut the ribbon cable and solder 4 wires to extend the gap to the desired length.
Each pixel contains a small microchip. The WS2801 LED driver chip is custom designed for this purpose. We provide an Arduino library for communicating with the pixels (explained in subsequent pages), but if you want to write your own code for other microcontrollers, they’re very easy to communicate with using an SPI-like protocol. For each pixel, one “shifts out” 24 bits of color information — the first data out corresponds to the pixel closest to the microcontroller. To write colors to 10 LEDs, you would issue 240 bytes (10 * 24). Following the data, a 500 microsecond pause will then “latch” the data and display the new LED colors.