I first want to thank AnotherHobby. I had been planning on this build for awhile, but it wasn't until I saw his impressive and clean looking design that I actually got off my butt and starting working on my own arduino based touchscreen GUI.
This isn't going to be my main thread about what I'm doing with my arduino, but until I have it finished, it will give an idea about what I'm doing with it.
Its an Arduino Due connected to a 4.3" touchscreen (480x277 pixels). I chose this size because it was the biggest size that the arduino would be able to draw without noticeable delays or lag.
I have some warm (3000K) LEDs, neutral (4300K) LEDs, and cool (6000K) LEDs that are individually controllable via separate power transistors being fed with the PWM output of the arduino. The idea is that it can emulate sunlight throughout the day, warm in the morning and cool at midday.
The main thing that I did differently that I haven't seen a lot in other LED setups is that I put large capacitors on the PWM output of the arduino which makes all the intensity changes really smooth instead of "steppy". Its pretty hard to control them this way, and I don't have them as smooth as I'd like, but the concept is there. You'll notice the current readings are really jumpy... this seems to be just kind of characteristic of the arduino DUE. When I used an UNO or MEGA they weren't so jumpy, so I'll have to modify my code to kind of smooth things out more.
The arduino will eventually control a bunch of other stuff like feeders, pumps, auto-topoff, sensor inputs, tank heater, etc., but I don't have any of that working quite yet.
Anywho, enough talk, here's a quick video. Don't mind the sad looking plants, I just now got my lights working properly.
BTW, here's my build journal for the tank for how I made the background and such: