Capacitive Soil Sensor

How many times have you watered your plants and feared you overdid it? With the capacitive soil sensor, those worries are a thing of the past!

Most cheap soil sensors work on the resistance principle, where there are two prongs and the sensor measures the conductivity between them. They work fine at first, but eventually begin to oxidize due to the exposed metal. Even if they are gold plated! Due to oxidation, the resistance goes up and up, so you have to constantly recalibrate your code. Also, resistance measurements do not always work in loose soil.

This design with capacitive measurement is superior. Capacitive measurements use only one prong, have no exposed metal, and do not introduce direct current into your plants.