How to Use DFRobot Gravity Alcohol Sensor: Examples, Pinouts, and Specs

The DFRobot Gravity Alcohol Sensor (SEN0376) is a high-performance sensor designed to detect the presence of alcohol in the air. It provides an analog output that corresponds to the alcohol concentration, making it suitable for a wide range of applications. This sensor is based on the MQ-3 gas sensor and is part of DFRobot's Gravity series, which ensures ease of use and compatibility with microcontrollers like Arduino.

• Breathalyzers for alcohol detection
• Alcohol concentration monitoring in industrial environments
• Safety systems for detecting alcohol vapors
• Educational and prototyping projects

The following table outlines the key technical details of the DFRobot Gravity Alcohol Sensor:

The sensor module has a 3-pin interface for easy connection. The pinout is as follows:

1. Power the Sensor: Connect the VCC pin to a 5V power source and the GND pin to ground.
2. Read the Output: Connect the AOUT pin to an analog input pin on your microcontroller (e.g., Arduino).
3. Calibrate the Sensor: Allow the sensor to preheat for at least 24 hours before use to ensure accurate readings. Use the onboard potentiometer to adjust sensitivity if needed.
4. Interpret the Output: The analog output voltage increases with higher alcohol concentrations. Use an analog-to-digital converter (ADC) to read and process the signal.

• Preheating: The sensor requires a preheating period of at least 24 hours for optimal performance.
• Ventilation: Ensure proper ventilation around the sensor to avoid saturation or false readings.
• Avoid Contamination: Keep the sensor away from water, oil, or other contaminants that may affect its performance.
• Power Supply: Use a stable 5V power source to avoid fluctuations in the output signal.

Below is an example of how to use the DFRobot Gravity Alcohol Sensor with an Arduino UNO:

// DFRobot Gravity Alcohol Sensor Example Code
// This code reads the analog output from the sensor and prints the value to the Serial Monitor.

const int alcoholSensorPin = A0; // Connect AOUT pin to Arduino analog pin A0

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 baud
  pinMode(alcoholSensorPin, INPUT); // Set the sensor pin as input
}

void loop() {
  int sensorValue = analogRead(alcoholSensorPin); // Read the analog value
  float voltage = sensorValue * (5.0 / 1023.0);  // Convert to voltage (0-5V)
  
  // Print the raw sensor value and voltage to the Serial Monitor
  Serial.print("Sensor Value: ");
  Serial.print(sensorValue);
  Serial.print(" | Voltage: ");
  Serial.print(voltage);
  Serial.println(" V");
  
  delay(1000); // Wait for 1 second before the next reading
}

1. No Output or Incorrect Readings:

   • Ensure the sensor is properly connected to the power supply and ground.
   • Verify that the AOUT pin is connected to the correct analog input pin on the microcontroller.
   • Check if the sensor has been preheated for at least 24 hours.

2. Fluctuating or Unstable Readings:

   • Use a stable 5V power source to avoid voltage fluctuations.
   • Ensure the sensor is placed in a well-ventilated area to prevent saturation.

3. Sensor Not Responding to Alcohol:

   • Verify that the alcohol concentration is within the sensor's detection range (0.04 mg/L to 4 mg/L).
   • Adjust the sensitivity using the onboard potentiometer.

Q: Can this sensor detect alcohol in liquids?
A: No, the sensor is designed to detect alcohol vapors in the air, not in liquids.

Q: How long does the sensor last?
A: The sensor has a long lifespan if used under proper conditions, but its sensitivity may degrade over time. Regular calibration is recommended.

Q: Can I use this sensor with a 3.3V microcontroller?
A: The sensor requires a 5V power supply for proper operation. If your microcontroller operates at 3.3V, you may need a level shifter for the analog output.

Q: Is the sensor affected by other gases?
A: The sensor is primarily sensitive to alcohol but may respond to other gases. Proper calibration and testing are recommended for specific applications.