I'm working on a small project, where I read up-to 12 brightness values from light dependent resistors (my schematic below only shows three). The basic layout is a voltage divider per sensor, which is feed into one of the ADC channels of a teensy microcontroller.
From the ADC I get a pretty good reading from 20-1000. I actually tried different resistor values for the voltage divider (R5) and I ended up with 47kOhms.
In some environments, I have lower light and I would like to make the voltage divider adjustable. With low light, my readings only go to 200-300.
I've tried to add a potentiometer, but this does not work. I'm not 100% sure why to be honest. Is there another way to do this? I want to have ONE adjustable potentiometer to change the voltage dividers on all channels.