Change polling frequency soil moist meter


#1

I’m using a Soil Moisture Meter (ebay) to measure the moist in my plants. But as a result of the high frequency polling, the sensor is wearing out.

It would be great if i can adjus the polling frequency of every sensor!

Thanks!

Rik


#2

I have seen a project for soil moisture that uses carbon electrodes. These can be extracted from old AA battery in some cases complete with a metalic / solder-able cap…

Put some gloves on, do some hacking and just boil up the extracted electrodes in some water in an old pot for a bit.
~ Andrew


#3

As a DC current is applied you get some electrolysis around the probes.
That is the water is broken down into hydrogen and oxygen and forms
microscopic bubbles on the surface of the electrodes. This reduces the
surface area in contact with the soil and hence reduces the resistance
measured. The only way round this is to use AC.

You SHOULD use AC not DC to take ressitance readings check out this setup
http://forum.arduino.cc/index.php?topic=37975.0


#4

What would be some polling timing specifications you would want to see in this feature? How often would you want to poll for your specific sensor?

Also, how do you know the sensor is wearing out? Does it should visible signs or are the readings deteriorating in accuracy?

-B