Humidity measurement with PIC16F877A

[jean12]

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!!

 

[BradtheRad]

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.

 

[Easyrider83]

**broken link removed**

 

[jean12]

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!!