Interface LDR with micro controller without using a ADC.

Thread Starter

thar07

Joined Jan 3, 2015
71
Can LDR interface with a micro-controller without using a ACD ?
TO use as a on/off switch which gives 0V and 5V s.
 

Magician

Joined Aug 18, 2014
13
Sure, you don't have to use ADC. Connect LDR with a resistor in series between power line and ground. Middle point goes to input of the uCPU. The problem is LDR has wide dynamic range, over 10^6, it's resistance change from ~100 Ohm in bright lighting condition to ~100 M Ohm in darkness. It's may be tricky to select right loading resistor
 
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