Automatic Plant Watering System with Arduino

To take good care of plants, time and effort are required. There are a few routine things that will occupy your daily life. You may experience plants dying when you were leaving home for vacation or just forgetting to water them. An automatic watering system is a suitable solution for those who want to look after plants in their house or office but barely have time to do it.

The automatic watering system monitors the soil moisture of plants and controls the water pump via a relay. A Seeeduino V4.2 or Arduino UNO is applied as the core of the system.

Seeeduino v4.2 is an alternative selection of Arduino UNO. if you are not familiar with this product, you may read this. I also assume that you have some basic knowledge of Arduino and C++ programming.

Hardware

Arduino UNO Rev 3 or Seeeduino V4.2: Brain of the system. Control all the components with your code.

Soil Moisture Sensor: Measures the soil moisture value.

Relay Module: Controls the motor to water the plant.

Grove Base Shield V2.0 for Arduino (optional): Provides a simple way to connect with Arduino boards

Construct the Demo

You will need to connect all the modules as shown in the diagram above. Besides the power supply, the soil moisture sensor connects to A0, and the relay connects to D4 to conduct the communication. If you do not like the soldering or wiring work, you may consider using a Base Shield to connect all other components.

Software

Before you start coding your board, please figure out:

1. The appropriate soil moisture for your plant. Then you can define the trigger of the water pump.

2. The flow rate of the selected water pump. To determine the working time of the motor.

// determine when to open the relay:
    if(sensorValue<200){

    // working for 3 second is sufficient
    digitalWrite(4,HIGH);
    delay(3000);            
    digitalWrite(4,LOW);
    }
    else{
    digitalWrite(4,LOW);
    }

Demo