A Simple DIY - Soil Moisture Detection

Some projects come our way that prove to be too cumbersome to build, others that demand a prerequisite know-how. Here’s a do-it-yourself that is simple and interesting and which was built in just about two hours.

This soil moisture detection system relies on two sensors. They are built with galvanized nails (not human nails, iron nails), which are then wired to an analog port. A resistor division with another resistor is created. For the sensors to work properly, the nails are separated by one and a half inches using foam pieces. As I mentioned, the system is very simple and cheap. You do not even need to use a galvanized nail. Manoel Ramon, the inventor of this DIY who is also an Intel engineer, did not want to see his nails rust in mud and air and hence chose galvanized metal.

The system can be used to detect if the mud has water in good quantity for the plants. If the water was enough, the happy face with LED brightened; if not a sad face. This sounds jocular but hey, this is a fun project and it is in keeping with the spirit of the fair.

This face has a push button which can be used to select the sensors. Each eye (LED) is signifies whether or not a corresponding sensor is on. To test the system, Manoel got two bowls or plastic cups and filled them with soil. One of them had more water than the other. Next, he wired each cup with a sensor. The idea is not to create a happy or sad face, the idea is to send a signal to a mechanical valve or a sprinkler to get on or off, thus automating the process.