How to Use Rainfall Sensor DFRobot: Examples, Pinouts, and Specs

The Rainfall Sensor DFRobot (Gravity_12C_UART) is a versatile sensor designed to detect and measure rainfall. It provides both analog and digital outputs, making it suitable for a wide range of applications. The sensor can detect the presence of rain and measure its intensity, making it an essential component in weather monitoring systems, smart irrigation systems, and other environmental monitoring projects.

This sensor is part of DFRobot's Gravity series, which is known for its ease of use and compatibility with microcontrollers like Arduino. Its robust design ensures reliable performance in outdoor environments.

• Weather monitoring stations
• Smart irrigation systems
• Rain detection for automated systems
• Environmental monitoring projects

Below are the key technical details of the Rainfall Sensor DFRobot:

The sensor has a 3-pin interface for easy connection. Below is the pin description:

1. Power Supply: Connect the VCC pin to a 3.3V or 5V power source and the GND pin to ground.
2. Signal Output: Connect the SIG pin to an analog or digital input pin on your microcontroller.
   • For analog output, read the voltage to determine rain intensity.
   • For digital output, adjust the sensitivity using the onboard potentiometer.

Below is an example of how to connect the Rainfall Sensor to an Arduino UNO:

• VCC → 5V on Arduino
• GND → GND on Arduino
• SIG → A0 (analog input) or D2 (digital input) on Arduino

The following Arduino code demonstrates how to read both analog and digital outputs from the sensor:

// Define pin connections
const int analogPin = A0; // Analog pin connected to SIG
const int digitalPin = 2; // Digital pin connected to SIG

void setup() {
  Serial.begin(9600); // Initialize serial communication
  pinMode(digitalPin, INPUT); // Set digital pin as input
}

void loop() {
  // Read analog value (rain intensity)
  int analogValue = analogRead(analogPin);
  Serial.print("Analog Value (Rain Intensity): ");
  Serial.println(analogValue);

  // Read digital value (rain detected or not)
  int digitalValue = digitalRead(digitalPin);
  Serial.print("Digital Value (Rain Detected): ");
  if (digitalValue == LOW) {
    Serial.println("Yes"); // Rain detected
  } else {
    Serial.println("No"); // No rain detected
  }

  delay(1000); // Wait for 1 second before next reading
}

• Sensitivity Adjustment: Use the onboard potentiometer to adjust the digital output threshold for rain detection.
• Placement: Ensure the sensor is placed in an open area where it can directly detect rainfall.
• Waterproofing: While the sensor is designed for outdoor use, ensure proper sealing of connections to prevent water damage.

1. No Output Signal

   • Cause: Incorrect wiring or insufficient power supply.
   • Solution: Double-check the connections and ensure the power supply is within the specified range (3.3V - 5V).

2. Inconsistent Readings

   • Cause: Dirt or debris on the sensor surface.
   • Solution: Clean the sensor surface gently with a soft cloth.

3. Digital Output Always HIGH or LOW

   • Cause: Incorrect sensitivity adjustment.
   • Solution: Adjust the potentiometer to set the desired threshold.

4. Analog Output Not Changing

   • Cause: Faulty sensor or improper placement.
   • Solution: Verify the sensor's placement and test with a known water source.

Q: Can this sensor detect the amount of rainfall over time?
A: The sensor provides real-time rain intensity data. To measure cumulative rainfall, you would need to integrate the data over time using a microcontroller.

Q: Is the sensor waterproof?
A: The sensor is designed for outdoor use, but the connections should be properly sealed to prevent water damage.

Q: Can I use this sensor with a Raspberry Pi?
A: Yes, the sensor can be connected to a Raspberry Pi using its GPIO pins. Use an ADC (Analog-to-Digital Converter) module for reading analog signals.

Q: How do I clean the sensor?
A: Use a soft, damp cloth to gently clean the sensor surface. Avoid using abrasive materials.

By following this documentation, you can effectively integrate the Rainfall Sensor DFRobot into your projects and ensure reliable performance.