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How to sense resistance with an arduino?

Is it possible to sense reistance between 2 poles or a material with an arduino.

The material's I want to read the resistance of are soil and water .

I know I can do it with a multimeter ,Im just asking if it is possible to do with an arduino and how.

Any suggestion?

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You can use a basic voltage divider.

Connect 5v to a probe which you stick into the soil. Stick another probe into the soil and connect it to an analog input pin, then connect a high value resistor from the analog pin to GND. Adjust the resistor size for sensitivity. The voltage on the analog pin will be related to the resistance between the probes.

This is the original one I found when looking for information on the same subject. At the time I was looking at setting up a micro greenhouse.


This is more of a full fleged setup....


This is what I want it for .

I want to make a watering notifiier.