Particle.io and WS2811 wake-up light

Here's a few things that may help you build a wake-up light with a Particle.io Photon and a string of WS2811 ("NeoPixel") RGB LEDs.

]

Hardware

For my wake-up light, I have connected 21 WS2811 LEDs to pin D6 of a Particle Photon. The Particle and power leads of the LED string feed off a 5V power adapter.

I usually power my LED creations with WS2811 LED "strings" (instead of strips). These are water proof (not really needed in the bedroom) and can be seperated by about 7cm, which is good to hang 21 LEDs over the width of our bed. I have used some mighty duct tape magic to hang the contraption from my bed frame.

Software

Particle.io code

The code that runs on the Particle is in wakeuplight.ino. It has two example functions:

• Start a 30 minute light sequence, simulating dawn and sunrise, with function wakeup
• Set the LEDs to a specified color, with function rgbColor which accepts values of the format 123,123,123 denoting R, G, B bytes.

If you want to run this from the Particle Build IDE, copy this code into a new project and add the "NEOPIXEL" library.

An example cronjob

You can start the wake-up light from a cronjob, e.g., at 7 each morning

0 7 * * 1,2,3,4,5 curl https://api.particle.io/v1/devices/MYDEVICEID/wakeup -d access_token=MYACCESSTOKEN -d "args=blah"

An example HTML/JS color controller

You can control the wake-up light's color from a native color picker using the JavaScript in the included index.html. Make sure to set your device ID and access token in the HTML file.