How to Use Rain Gauge: Examples, Pinouts, and Specs

A rain gauge is an essential instrument used in meteorology to measure the amount of precipitation that falls over a specific area during a given period. This DIY Rain Gauge (Part ID: 1) is designed for hobbyists, researchers, and weather enthusiasts who wish to monitor rainfall patterns for agricultural, hydrological, or climatological purposes.

• Agriculture: Determining irrigation needs based on rainfall.
• Hydrology: Monitoring and managing water resources.
• Meteorology: Studying weather patterns and contributing to climate data.
• Education: Teaching students about weather and environmental science.
• Personal Interest: For individuals interested in weather patterns and gardening.

• Measurement Range: 0 to 9999 mm
• Resolution: 0.1 mm
• Accuracy: ±1%
• Operating Temperature: -10°C to +50°C
• Material: UV-resistant plastic

1. Power Supply: Connect the VCC pin to a 5V power supply.
2. Ground: Connect the GND pin to the ground of the power supply.
3. Signal Output: Connect the Signal Output pin to a digital input pin on a microcontroller, such as an Arduino UNO.

• Ensure the rain gauge is mounted level and in an open area to accurately collect rain.
• Avoid placing near trees or buildings that may block or divert rainfall.
• Regularly clean the collection funnel and the tipping bucket mechanism to prevent debris from affecting measurements.
• Calibrate the device periodically to maintain accuracy.

// Define the digital pin connected to the rain gauge
const int rainGaugePin = 2;

// Variable to store rainfall count
volatile unsigned int rainCount = 0;

// Interrupt service routine for the tipping bucket
void rainISR() {
  rainCount++;
}

void setup() {
  // Initialize the serial communication
  Serial.begin(9600);
  
  // Set the rain gauge pin as an input
  pinMode(rainGaugePin, INPUT_PULLUP);
  
  // Attach an interrupt to the rain gauge pin
  attachInterrupt(digitalPinToInterrupt(rainGaugePin), rainISR, FALLING);
}

void loop() {
  // Disable interrupts to read rainCount safely
  noInterrupts();
  unsigned int rainCountCopy = rainCount;
  rainCount = 0;
  interrupts();
  
  // Calculate the amount of rainfall in mm
  float rainfall = rainCountCopy * 0.1; // Each tip is 0.1mm of rain
  
  // Print the rainfall amount
  Serial.print("Rainfall: ");
  Serial.print(rainfall);
  Serial.println(" mm");
  
  // Reset the rain count
  rainCount = 0;
  
  // Wait for 1 second before the next loop
  delay(1000);
}

• Inaccurate Readings: Ensure the rain gauge is level and free from obstructions.
• No Readings: Check the wiring and ensure the interrupt pin is correctly configured.
• Erratic Readings: Debris may be interfering with the tipping mechanism; clean the gauge.

• Calibration: Periodically calibrate the rain gauge by simulating rainfall and adjusting the count as necessary.
• Maintenance: Regularly clean the rain gauge to prevent debris from affecting the readings.
• Wiring Check: Revisit the connections to ensure they are secure and free from corrosion.

Q: How often should I clean the rain gauge? A: Clean the rain gauge at least once a month or more frequently if located in a dusty or leafy environment.

Q: Can I use a longer cable to connect the rain gauge to the Arduino? A: Yes, but ensure that the cable is of high quality to prevent signal degradation, and consider using shielded cable for long distances.

Q: What should I do if the rain gauge is not responding? A: Check the power supply, ensure the gauge is clean, and verify that the interrupt service routine is correctly configured in your code.