This project makes use of a soil moisture sensor module to detect levels of moisture in the soil. If the moisture level is low, the submersible 5V pump pumps water from a source through the tubing into the plant. The soil moisture sensor then detects the moisture and the water stops pumping. The code is set up to perform checks every 12 hours on the moisture level in the soil.
The project does not make use of a relay module as the pump used worked well with low voltage. Some motors and pumps may not work so well under a low voltage in which case the use of a external power supply and relay is required.