What is it?

This is a water condensation sensor. It's similar to a rain sensor, except that the traces are 0.2mm thin, giving it the ability to sense the smallest water droplets that form due to condensation. When taking a hot shower, the mirrors in your bathroom will fog up due to condensation. This sensor gives you the ability to detect such an event (something that an ordinary rain sensor cannot do).

To use it, connect one pin to GND and the other to an analog / digital input pin using pullup. If water is condensed onto the sensor's surface, the pin will be pulled to GND.

Why did you make it?

Rain sensors are only good at detecting large droplets of water. But I needed something that can detect water moisture at a much finer level. I did not find any such sensors on the internet and decided to make my own.

What makes it special?

It is a one-of-a-kind sensor that you probably can't find anywhere else.

One potential use case for this cheap condensation sensor is in home humidity monitoring. By placing the sensor in a room, homeowners can keep track of the humidity levels and detect any condensation that may be forming on windows, walls, or ceilings. This can help prevent issues such as mold growth or water damage. Another potential use case is in industrial settings where condensation can be a problem. For example, in food processing plants or breweries, condensation can form on equipment and surfaces, leading to hygiene concerns and potential product contamination. A condensation sensor can help detect when condensation is forming so that appropriate measures can be taken to prevent it. This affordable condensation sensor can also be useful in automotive applications. For instance, it can detect when condensation is forming on the windshield, allowing drivers to take steps to prevent it from obstructing their vision. Alternatively, you could utilize the device to automatically power down your electronic equipment in the presence of condensation, thereby eliminating the risk of short circuits.