I've got a Input/Output board that is connected to my pc for a project I'm working on. What I want to do is to connect a LDR (light dependent resistor) to one of the analogue inputs. I'm guessing I can't just connect a ldr and a 12v power supply together and run it to the analogue input on the io board. Any ideas ? The circuit should make use of a 12 volt powersupply. ???