hey Mike! thanks for the response!
I am currently testing with an HCT138 but that was what I used for an LED array and it was laying around..
Also radio shack 5pack photo resistors for the time being, rough i know, i will hit digikey when I get a better scope of what is going on.
I am perfectly fine with adding 16 op-amps, monostable multivibrators and whatever to the mix as needed.
I'm pretty sure the A/D via PIC18f2550 is pretty capable of doing what I need. there are two comparator modules on board, as well as just about everything else under the sun...
but in all reality, what I need is to trigger the ambient reflection of a pen laser at several places for an art project. There is a lighting display that causes fluctuations in light and I need some way to react to the curve of resistance caused by a photocell when subjected to changing lights, ending up in boolean true/false, yes the laser was tripped, no it was not. The laser is reflecting all over the place and I am detecting where it is triggered and changing the lighting accordingly. I dont feel IR would be suitable.
So basically heres the formula and what I need:
Bright ambient Light -> photocell range very small when laser is tripped(.2 to .4V), threshold voltage is .3V
Dark ambient light - > bigger photocell range(.6 - 2.6V), threshold voltage is 1.5V
I need a method to auto-detect the different lighting scenarios and set the threshold accordingly. I either need a good logic signal to send the microchip or to use the features of the microchip to handle the situation.