If you’re designing your own intelligent with an optional digital plant moisture sensor/water pump controller that lights an LED to alert the user when it’s time to water a potted plant, and/or activate a pump to quench the thirst, here is an Arduino Primer for you. No doubt, an Arduino can convert your favorite pots into self-watering planters, keeping your plants from drying out and reducing the time you spend watering. The self-watering system is right for people frequently on vacation and takes the guesswork out of watering. Plants draw up moisture as they have it!

one of the items that crop up to your mind is that the automatic measurement of the moisture content of the soil. If you’re building a sensible Garden that waters plants automatically and provides you the readings of the wetness of the soil, then you’ll definitely need a Soil Moisture Sensor.

In this Instructable, I’ll show you ways to interface the Soil Moisture Sensor to an Arduino Uno and skim the values on a Serial Monitor.


This digital output (wet soil → L / dry soil → H) is routed to at least one I/O terminal (any Digital Pin)of the Arduino microcontroller. supported this input (at Digital Pin) Arduino gives an active-high (H) output through Digital Pin when soil is dry, and an active-low (L) output when soil is wet.

  • Now connect the Analog Data Pin to the A0 pin on the Arduino (Since I’m interested in Analog Data).
  • Connect the two pins from the Sensor to the two pins on the Amplifier circuit via hook up wires.
  • Connect the Vcc from the Amplifier to the 3.3V pin on the Arduino and the GND pin to the Gnd pin on the Arduino.