Water Level Detection System Using ESP32

#define RELAY_PIN   13  // The ESP32 pin GPIO13 that connects to the relay to control the pump
#define POWER_PIN   32  // The ESP32 pin GPIO32 that provides the power to the water sensor
#define SIGNAL_PIN  34  // The ESP32 pin GPIO36 that reads the value from the water sensor

#define THRESHOLD   1000 // The threshold for water detectiion

void setup() {
  Serial.begin(9600);
  pinMode(RELAY_PIN,   OUTPUT); // configure D2 pin as an OUTPUT
  pinMode(POWER_PIN, OUTPUT);   // configure D7 pin as an OUTPUT
  digitalWrite(POWER_PIN, LOW); // turn the water sensor OFF
  digitalWrite(RELAY_PIN, LOW); // turn the pump OFF
}

void loop() {
  digitalWrite(POWER_PIN, HIGH);  // turn the water sensor's power  ON
  delay(10);                      // wait 10 milliseconds
  int value = analogRead(SIGNAL_PIN); // read the analog value from sensor
  digitalWrite(POWER_PIN, LOW);   // turn the water sensor's power OFF

  if (value < THRESHOLD) {
    Serial.print("The water is detected");
    digitalWrite(RELAY_PIN, LOW);  // turn the pump ON
  } else {
    digitalWrite(RELAY_PIN, HIGH);   // turn the pump OFF
  }

  delay(1000); // pause for 1 sec to avoid reading sensors frequently to prolong the sensor lifetime
}