Problem: I own a home that I'm not always at, It rains there a lot and I need a way to monitor if there is rain by using a sensor so i can turn on a pump to move the water away from my house.
Solution: I'm using a raspberry pi to do all the heavy lifting. So I have a relay along with code that talks to everything. The raspberry pi is the easy part of this. I'm a CS not a EE.
My question: I'm looking for a sensor that will last outside without any maintenance, for up to 6 months. That will sense if it is wet and talk to the raspberry pi. I found a sensor.
http://www.seeedstudio.com/wiki/Grove_-_Water_Sensor
That I'm pretty sure i can hack up, but haven't found anything that looks a bit more "long term." For my application, i think im going to really test the hell out of this, if it breaks i would have to monitor my house physically with a web cam to see if its flooding. If i found a sensor thats reliable, i could save time by not worrying about it at all, and letting the sensors + raspberrypi + notifications to do all the "worrying" for me.
Best Answer
To begin with, there are several technologies for water sensing, with varied degrees of robustness. See these questions: Are there existing electronic sensors that can sense if underwater or not? and How does this soil moisture sensor work?, as well as some others on this site.
Some of these options, including a variant on the Grove sensor in the question, can be made robust enough to last years - simply by environment-proof epoxy / conformal coating of the entire sensor circuit other than the sensor strips themselves. This is one of the methods used by remote weather monitoring stations.
The soil moisture sensor is particularly attractive, as those are designed to be deployed for years of operation anyway.
Given that it is rain that needs to be sensed, an alternative approach would be this: