Introduction: Automatic Plant Watering
Automatic watering station: module will check the humidity of the soil and water the plants when soil is too dry.
For this project you need:
- Arduino (I used Arduino Nano, but any arduino will do)
- Soil humidity sensor + amplifier
- Relay module
- Low pressure water pump (I used one made for aquariums)
- Power sources (5v for arduino + 12v for water pump)
- Cables (to connect everything together)
Step 1: Connect Soil Humidity Sensor to Amplifier
Connect "+" and "-" pins of the amplifier to the pins on the humidity sensor
Step 2: Connect Humidity Sensor Amplifier to Arduino
Connect the pins of the soil humidity sensor amplifier to Arduino:
- Amplifier pin "AO" to Arduino pin "D4"
- Amplifier pin "GND" to Arduino pin "GND"
- Amplifier pin "VCC" to Arduino pin "3v3"
Step 3: Connect 12v Power Source to Water Pump With Relay
Connect the 12v Power source to the water pump through the relay:
- Power source "minus" to "minus" of Water Pump
- Power source "plus" to "COM" on Relay
- Relay "NO" to "plus" of Water Pump
Step 4: Connect Relay to Arduino
Connect Relay pins to Arduino pins:
- Relay pin "+" to Arduino pin "5v"
- Relay pin "-" to Arduino pin "GND"
- Relay pin "s" to Arduino pin "D4"
Step 5: Upload Code to Arduino
- Connect your Arduino to your computer using the USB cable.
- Open Arduino IDE (if you do not have this installed yet, you can download it at: https://www.arduino.cc/en/Main/Software)
- Upload code:
void setup() { Serial.begin(9600); // initializes serial communication at 9600 bits per second pinMode(4, OUTPUT); // sets pin for relay in output mode }
void loop() { int sensorValue = analogRead(A0); // read value of humidity sensor Serial.println(sensorValue); // prints value to serial if(sensorValue > 700){ // checks if value is below treshold, treshold is set at 700, but should be costumized for your plants need digitalWrite(4, HIGH); // turns relay on delay(1000); // waits for 1sec } else{ digitalWrite(4, LOW); // turns relay off delay(1000); // waits for 1sec } }
Attachments
Step 6: Test the System
Hook up the power sources for Arduino and Water Pump
- When putting the soil humidity sensor in water: water pump should turn off
- When removing the soil humidity sensor from water: water pump should turn on
Step 7: Install the System in Plant Pot
Plant the soil humidity sensor in the soil and set the incomming end of the Water pump in the water reservoir (big pot) and the outgoing end in the soil.
Enjoy your plants without having to think about watering them again!