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Topic: Sharing Grounds for LDRs (Read 670 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.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

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