ESP32-S3 Rain Drop with Arduino IDE

Introduction

The Raindrop Sensor is used to detect rainfall using a rain-sensing board and a control module.
The sensor provides both analog and digital outputs, which the ESP32-S3 can read to determine rain intensity or presence.
It is commonly used in automatic wiper systems, agricultural irrigation, and home automation for smart weather response.

Required Components

• ESP32-S3 Board
• Rain Drop Sensor
• Jumper wires
• Breadboard

Pinout

Circuit Diagram / Wiring

• Rain Sensor VCC → VIN (ESP32-S3)
• Rain Sensor GND → GND (ESP32-S3)
• Rain Sensor DO → 14 (ESP32-S3)
• Rain Sensor AO → 13 (ESP32-S3)

Code / Programming

/*
  Filename: ESP32-S3_raindrop_sensor.ino
  Description: Reads analog and digital values from a raindrop sensor using ESP32-S3.
               Digital pin reports rain detection. Analog pin gives intensity.
  Author: www.oceanlabz.in
  Modification Date: 1/4/2025
*/
 
// Define sensor pins
const int analogPin = 13;  // Use an ADC1-compatible analog pin on ESP32-S3
const int digitalPin = 14; // Digital output pin from the sensor
 
void setup() {
  Serial.begin(115200);        // Start serial communication at 115200 baud
  pinMode(digitalPin, INPUT);  // Set digital pin as input
  Serial.println("Raindrop Sensor Initialized");
}
 
void loop() {
  int analogValue = analogRead(analogPin);      // Read analog value
  int digitalValue = digitalRead(digitalPin);   // Read digital output
 
  Serial.print("Analog Value: ");
  Serial.print(analogValue);
  Serial.print(" | Digital Value: ");
  Serial.println(digitalValue == LOW ? "Rain Detected" : "No Rain");
 
  delay(1000);  // Delay before next reading
}

Explanation

• The sensor detects the presence and intensity of rain using a conductive surface that changes resistance when wet.
• The analog pin on ESP32-S3 measures moisture level, while the digital pin detects rain presence (HIGH = dry, LOW = wet).
• This setup is ideal for automating actions like alerts, wipers, or irrigation during rainfall.

Troubleshooting

• Analog Value Always 0 or 4095: Ensure the sensor’s analog pin is connected to an ADC1-compatible GPIO (e.g., GPIO13) and the board is powered with at least 3.3V.
• Digital Output Always HIGH or LOW: Adjust the sensitivity potentiometer on the sensor module to detect correct rain levels.
• No Serial Output: Make sure Serial Monitor baud rate is set to 115200, and the correct COM port is selected in the Arduino IDE.