WS2812 light string for evening TV watching

Hey all, after doodling with the Core, Photon, and Electron, I finally finished a project- TV backlighting that is driven by the current time of sunset/twilight. I used a 1-meter strip of 2812 LEDs, with 144 to the meter, and then cut about a dozen off one end so it would fit my TV and a 10A 5V power supply to feed both the LEDs and the Particle. I then used some double-sided tape to stick the Photon on the back of the TV and wrote some code.

Since I’m much more a coder than an electronics cat, I wanted to leave the time on the Photon in UTC and just shift all my calculations. I’m on the US West Coast, so I’m 7 or 8 hours off, which explains the weird times in the conditionals.

Here’s the code. Thanks to the @BulldogLowell for the “sunrise” library, which kept me from dealing with the messy math. (though- feature request- let me query for “time until sunset”/“time since last sunset” with relative numbers?)


(yes, the 2812s are overkill for this)


cool, another project to add to my list! (thinking about powering with the USB on the back of my set)

FYI, you can get your DST offsets automagically with a webhook:

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Thanks- I’ll add that webhook.

If you power off USB you will be power-limited, of course.