I’m looking for a simple way to detect if water is on a surface, as in a leak needs to be detected. In actuality, it would be inside a dehumidification unit and I’m trying to detect if the drain line has clogged and water is backing up inside the unit. I’m already planning on utilizing a float switch, but I’d also like to look at the possibility of detecting when water is starting to collect.
I believe I’ve seen a couple simple circuits involving merely two conductors separated by a relatively small distance and then bring this into an analog input. The device would detect the change in input level when water allows conduction between the conductors.
Simple soil moisture sensors could be used for that.
@ScruffR, thanks for the suggestion. As it turns out, I looked at the schematic for that sensor and decided to design my own board with that circuit and my Photon on the same board along with a few other small circuits. It also will require only 2 conductors to the home-made sensor (conductive strips). It has tested very well and will be a bit easier to install in our application. However, I really appreciate the suggestion, as it got me heading in the right direction!
Let us know how it turns out!
I made something like this recently to find out why my freezer was leaking water. I simply used two wires to create an analog input, and attached the wires to a paper towel, that would soak up the water and increase its conductivity. Whenever the conductivity (analog reading) got over a certain point, my Photon would call webhook that would send me an IFTTT notification.
I also powered my photon using a 9V battery, and I had to implement offline cycles to save power. Basically, every minute the Photon would take an analog reading. If the reading was high enough, the Photon would come online, trigger the webhook, and then go offline, waiting for 30 minutes to take the next reading. This way, you get get a maximum of 2 notifications per hour, and the Photon would remain offline whenever it was not time for it to take a reading, saving a lot of battery.