Studying the Hardware Needed

The most difficult part: decide which hardware you're going to build/ use for this. I've picked the display, first, to see options and ease to use it out-of-the-box.

As I've explained before, I live in Brazil, and for that, not all hardware is available in electronic shops around here. I was searching for a usable LCD touch display, with a decent area and enough power to display sliders and send them in a timely manner to Arduino, so it can treat it accordingly. None of the locally available displays seemed feasible (too small - 2.4 inches, are you kidding me? - 9600 bits comms, or too much fancy - capacitive sensor, which would deeply hit my budget to the project), so I started to look into Adafruit / hackaday / other forums to see what the other guys were using. I've crossed to 4D Systems 3.2" LCD touch (http://www.4dsystems.com.au/product/uLCD_32PTU_AR/) which has a powerful SoC, easy to connect to an Arduino host, easy to use libraries, loads of stuff that you can program / use straight with this device. Perfect choice! Small step back: due to customs, it added almost 50% of the cost just in import taxes, but for the functionality, seems ok!

Arduino controllers are common / simple / easy to use, but one question remained to me: would it be fast enough to control the dimmers (even more with added dimmer channels)? You have to have in mind that these controllers have a 16 MHz oscillator and, in theory, would be able to have one processing cycle in :

1000000 (us) / 16000000 (MHz) = 0.0625 us

That it would easily fit in our handling for the dimmers:

1000000 (us) / 100 (levels) / 60 Hz * 2 (fire angle for Triacs) = 83.3 us.

Adjusting to my options, I had:

1000000 (us) / 80 (levels) / 60 Hz * 2 (fire angle for Triacs) = 104.1 us

Even better!