Bill,
That's basically the functionality I've written into the basic firmware. For each of the channels of LED, you get to program the following:
Start time: self-explanatory.
Photoperiod: self-explanatory.
Fade Duration: The amount of time the channel takes to fade from zero (at the start time) to full power.
Max Intensity: The % it hits at max power.
And of course, since it's an Arduino, you can write or use any code you want to do anything else - moonlight control, using a different start time/photoperiod each day to simulate natural changes in day length, cloud simulation, and so on.
Also, I put pinouts for the I2C and Serial ports on the edge of the board, so you can easily expand the basic hardware. For instance, if you decided in a year that you wanted to display pH, you could build any of the popular pH circuits, slap an I2C ADC on it, and plug it in.
Or, you could use a multiport I2C ADC and add a few temp sensors. I may design a simple "Typhon add on" for temp sensors, since it could arguably be used in controlling your LEDs - you could rig the temp sensors to the heatsinks and have the Typhon shut your LEDs off if it detected an unsafe temperature (due to a fan failure or other such event).
