Wawa:
13x7 is weird from a digital point of view. Can't you change it to something like 8X16 (128 LDRs).Sparkfun has 16channel analogue muxer boards.
100n from each muxer input to muxer ground, pull up resisor from each muxer input to muxer VCC.
LDRs between muxer inputs and muxer ground.Could use a Nano (8 analogue inputs) for the 8 muxer outputs (8x16) and four address lines.
Leo..
That is true. 13x7 just worked out nicely since it spread the LDRs evenly at a good spacing on the display. Bumping it up to 16x8 seems like a pretty good idea, but I will need to make sure the LDRs would spread out evenly over the display. Also, that chip does look pretty perfect for my use case, thanks! When you say 4 address lines would be needed for the mux chips, that means all the chips address lines would be linked together? I suppose there is no need to have them separate, so that should work nicely.