The soil moisture sensor module , built around the LM393 comparator ... The +5V supply line (VCC) of the module is linked to the 5V line of the Arduino. GND of the module is the common (0V) connection ...

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 ...