Soil moisture sensor help

Other Hardware Sensors
1

Hi, I am currently working on a project for plant watering system. Right now i'm just testing and having fun, but in future i'm planning on putting a real time application and running it for weeks, months etc.

At the moment I am using http://www.aliexpress.com/store/product/Soil-Hygrometer-Detection-Module-Soil-Moisture-Sensor-For-Arduino-5pcs-lot/809689_714793698.html this moisture sensor and it is rather horrible, starting by the randomly increasing/decreasing moisture to corosian.

I am looking for any tips for a moisture sensor, which could be realible for more than a month + give precise readings and also wouldn't cost too much.

2

The corrosion is partly because there is a constant current flowing.
If you only put voltage to the sensor if you want a reading (e.g. once per hour) the corrosion should be less.

hope this helps,

3

Thanks, that helps a lot, but still the sensor is mostly only a toy, I am looking for a real time application. A different more long-lasting model would be great.

4

To avoid electrolysis, flip-flop technique seems to be a good idea.
http://gardenbot.org/howTo/soilMoisture/