It's not precisely an Arduino question, but I'm hoping you can help me. I'd like to connect 4 photoresistors to 4 analog inputs on the Arduino board. The schematic I'm using and a picture of the hardware setup is below. So I've got 5V into a 10K pot for bias adjustment, then it splits out to four 4.7K resistors, connects to the analog in, and passes through the photoresistor to reach ground. Here's the schematic:
And a picture:
The problem is that changing the value on one photoresistor also causes the others to change. I'd like to isolate them better. I could use larger resistors, but as the 5% tolerance becomes closer to the total resistance range of the photoresistor, I'm going to have problems with calibrating all of them equally. Any help? Maybe throw a diode in there somewhere?