5.3 Automatic watering device

Description：

We have learned how to control the water pump and read the value of the soil humidity sensor, you can control the relay by observing the value detected by the soil moisture sensor to realize a simple automatic flower watering device.

Test Code

#define soilPin1 A0
#define soilPin2 A1
#define soilPin3 A2
#define soilPin4 A3
#define IN1 3
#define IN2 5
#define IN3 6
#define IN4 9

void setup() {
  Serial.begin(9600);
  pinMode(soilPin1, INPUT);
  pinMode(soilPin2, INPUT);
  pinMode(soilPin3, INPUT);
  pinMode(soilPin4, INPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
}

void loop() {
  int val1 = analogRead(soilPin1);
  int val2 = analogRead(soilPin2);
  int val3 = analogRead(soilPin3);
  int val4 = analogRead(soilPin4);
  Serial.print("SoilSensor 1 =  ");
  Serial.print(val1);
  Serial.print("  ");
  Serial.print("SoilSensor 2 =  ");
  Serial.print(val2);
  Serial.print("  ");
  Serial.print("SoilSensor 3 =  ");
  Serial.print(val3);
  Serial.print("  ");
  Serial.print("SoilSensor 4 =  ");
  Serial.println(val4);
  if(val1 < 420){
    digitalWrite(IN1, HIGH);
  }else{
    digitalWrite(IN1, LOW);
  }
  if(val2 < 420){
    digitalWrite(IN2, HIGH);
  }else{
    digitalWrite(IN2, LOW);
  }
  if(val3 < 420){
    digitalWrite(IN3, HIGH);
  }else{
    digitalWrite(IN3, LOW);
  }
  if(val4 < 420){
    digitalWrite(IN4, HIGH);
  }else{
    digitalWrite(IN4, LOW);
  }
}

Test Result

Upload the test code, touch and hold the soil moisture sensor with your hand, the corresponding relay is turned on, and the water pump pumps water. After releasing the hand, the relay is turned off and the water pump stops pumping.