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Humidity measurement with PIC16F877A

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Advanced Member level 2
Aug 27, 2013
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Hello,I would like to take measurement underground,for making an automatic pump which react depending to the value of underground Humidity(Moisture),can you help me to implement this.

Thank you.

Please help!!

I suppose you wish to detect water (flooding)? And that will start a pump operating?

(Asking for clarification, because humidity is a term for moist air.)

A float switch is a reliable, common method to turn a pump on and off. It is suitable for water that is a few inches deep.

Or, if you wish to detect a shallow puddle, it is possible to construct a water detector. Two wires, or copper strips on a circuit board, etc. Connect these to a sensitive transistor or other amplifying device.

If water bridges across the two contacts, it will conduct a small amount of electricity. The signal will be detected and amplified. You can use this to close a relay which operates your pump.

The pump will stay on until the contacts cannot pass a signal. You may not wish it to continue that long. Therefore you may need to add a timer, or other circuit, which will shut off the pump.

Over time the contacts may acquire dirt, film, etc. This can prevent proper operation. They'll need to be cleaned every so often.

Hello,I have a moisture sensor VH400 which I would like to interface to a PIC16F877A so depending to what I detect with the sensor,the PIC commands the pump and this turns on for irrigating.

Could you please help with VH400 datasheet?

Thank you!!

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