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Topic: Sharing Grounds for LDRs (Read 657 times) previous topic - next topic



New to the Arduino platform and had a quick question in regards to LDRs: I have 5 LDRs which I would like to read the amount of light from with my Arduino Uno, I'm connecting all 5 of their wires together and attaching it to the 3V pin and am wanting to read all of the values received in the analog read ports. The question which I have is can I share the ground for these LDRs, so could I attach 1 wire from every LDR together and then attach that to a resistor and to ground or do I need a resistor for each and every one which I can then connect to ground.

Any help would be much appreciated.


You need a separate resistor for each LDR. Otherwise light changing on one LDR will affect the reading from another one.

The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons


All right, Thank you Very much!


Yes you can have them connected to the same ground. Just use fixed resistors in series with LDRs.

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