Hi all. I’ve been designing/building this loft for my 4-year-old daughter, and what started out as a plan to install white LED strips with a simple dimmer morphed into what I’ve told her is a “magic ceiling.” The LED strips are going to sit between the ceiling rails and the ceiling boards in some channels that I made with a router (shown by the red lines in the picture). I think the light reflecting off the ceiling boards and spilling across the surface should give a cool effect.
I’m also planning to have a panel with some large knobs and a few buttons that can be used to control the lights. My thoughts right now are 3 knobs for RGB (she can learn about mixing colors), one knob to control animation speed, and as many push buttons as required (not shown, but will be on the side of the control panel facing the corner). I figured one button could cycle through pre-set colors and a few animations, but I haven’t really settled on that.
The reason I’m posting here is because, I want advice. What would you do? How would you set up the LED’s? A matrix, individual strips, mirrored strips? What kind of animations do you think would look good? Would you design the control panel differently?
Also, how would you turn the system on/off? The power supply and Arduino are going to sit up inside the ceiling panels (with a small access hole). I was going to run 120V AC up to the power supply with an extension cord inside some wall mounted conduit (and use the same conduit to run the control cables back to the panel). The plan right now is to just have an on/off switch on the control panel that cuts the AC to the power supply. Any ideas/improvements are appreciated.
For something like this, addressable LEDs may be overkill. Have you thought about using analog 12v strips and something like this? https://www.adafruit.com/product/678
Of course it’s overkill 
and of course I thought about something simple, off the shelf. I guess I’m not one to go with the simplest solution.
I would cut AC power and have easy disconnect for control card. For adding interactions with code view some of the know how show on Twit.tv they did some good stuff on using pots and switches.
What a cool dad! =)
I think the strip setup may be a little sparse for a matrix, but I would still give it a try.
Maybe consider controls like this: a knob each for R, G, B that makes solid colors, a fourth for brightness/off, a fifth to cycle between six or eight palettes via the noise palette sketch (like clouds, lava, party colors, etc.) and a sixth to change the speed of the noise animation.
I built a setup sort of like this for a 16x16 matrix (with a knob for noise scale, but not the RGB) and it’s pretty satisfying to play with. The advantage of potentiometers over buttons is that they automagically save state; you can just turn the brightness down to zero and then a day (or a week) later turn it back up and everything is as before.
For extra-extra fun, the last “slot” (input range) on the palette select knob could create a completely random palette…so that by turning the knob all the way right, then back left a little and then right a little she’d get a brand new look each time.
Pictures/video when you get it installed, please!
@Erik_Mellquist cheers to that. 
I might consider something even simpler: fiber optics. You can buy a kit off of ebay and install it yourself. And if you’re a tinkerer like me, you can modify it and add multiple high powered LEDs so you can have multiple colors at the same time, instead of a single shade across the whole thing.
Great ideas @Chad_Eby ! I like the idea of using a knob to set the mode instead of a button.
Definitely go for a matrix (or at least one long continuous strip). It’ll be much easier to program “waves” of color moving from one end of the ceiling to the other. Also, if you program in some random color changes, it’ll be far more random (multiple strips off the same pin, for example, would just mimic each other, so not really random).
This will be a great ceiling for you to be under when you receive your Dad of the Year award!