This is a simple arduino project for a soil moisture sensor that will light up a LED at a certain moisture level. It uses Arduino Duemilanove microcontroller board. Two wires placed in the soil pot ...

[Lord Feistel] gives us a demo of how this could work with nothing more than poorly designed code, a resistor, and an oscilloscope. The hardware side is, as mentioned, really simple.

An Arduino can measure time, a coil and a resistor will create a delay proportional to the circuit values, and metal around the coil will change the coil’s inductance.