Holiday Lights

Some twinkling lights for your tree/menorah/office/door/roof/habitrail.

Materials

Uses WS2811 lights, available from Adafruit and fine retailers worldwide.

If you've got more than 100 lights in a string, you're probably also going to want an external 5v DC power supply. I found a good 10A power supply for about $12 on Amazon. You can probably salvage one from some old thing.

If you have under 80 lights, you can use an Adafruit Trinket. I used an Adafruit Pro Trinket for mine, which has 150+ lights. (It's an issue of RAM).

Of course, a standard Arduino will work just fine too!

Setup

Plug your lights into pin 6 (or whatever you set PIN to in the code). Set NUM_LEDS in the code to how many are in your strip.

Give the strip power and ground. If you have more than about 80 LEDs, you might need to provide an external 5v power supply, since USB can only provide 2 amps. You can plug the LED strip into the +5v on the power supply; You can power your microcontroller from the beefier power supply, too, so you don't have to run USB just to power the microcontroller.

This was coded to color-correct a specific type of GRB LEDs on wires I got from Amazon. It's coded to match the lights we already have, which are biased toward yellow and amber. Some of the lights are wired differently and the colors are going to be wrong. Play around, commenting out all but one color, to see if it's right.