The light dependent resistor (LDR) that I use in MintyTime, Excelitas Tech VT93N2, has been discontinued by the manufacturer. I'm having trouble finding a comparably priced (e.g. < $0.50 @ 100+) replacement part. It's been suggested to me that I should consider/investigate using a photo-diode (photo-detector,) like this one, as a replacement part. Here is a snippet from my schematics where the LDR is used:
The LDR plugs into the SENSE_IN and SENSE_OUT nets. The SENSE_IN and SENSE_OUT nets then go to I/O pins on my ATTiny2313 micro-controller. SENSE_IN goes to an analog comparator input and SENSE_OUT goes to a digital I/O pin that I use to "turn on" the voltage divider formed by the LDR and fixed 22kOhm resistor when I want to take a reading (to save some power by not driving the divider constantly.) I'm only trying to detect two ambient light states anyway "dark" and "normal" so that I can dim the LEDs when it's dark.
On to the question(s).
If I use a photo-diode (like the one I've linked to) by plug in the anode into SENSE_OUT and the cathode into SENSE_IN should it be software / hardware compatible with an LDR as I've described its use in my application? My gut says yes, but I haven't used photo-diodes before, and I thought I remembered something about them only responding to intentional signaling (like IR) rather than light levels. Can you recommend a different one that is more appropriate / cheaper for my needs?
Alternatively, are there actually more widely available low-cost LDRs and I've just managed to overlook them in my searches at the major suppliers (e.g. Mouser, Digikey, and Newark)?
Whatever I do, I'll obviously have to buy a few and try it out.