How to Use PM2.5: Examples, Pinouts, and Specs

Particulate Matter 2.5 (PM2.5) sensors are electronic devices designed to measure the concentration of fine particulate matter in the air. These sensors are critical for air quality monitoring and are commonly used in environmental monitoring stations, air purifiers, and HVAC systems to detect and control pollution levels.

• Air quality monitoring
• Environmental data collection
• Smart home systems
• Industrial air filtration systems
• Health and safety monitoring in workplaces

• Measurement Range: Typically 0 to 500 µg/m³
• Operating Voltage: Usually 5V DC
• Output Signal: Analog voltage, PWM, UART digital output (varies by model)
• Response Time: T90 < 1 minute
• Operating Temperature Range: -10°C to +60°C
• Operating Humidity Range: 0 to 95% RH, non-condensing

1. Connect the VCC pin to a 5V power supply.
2. Connect the GND pin to the ground of the power supply.
3. Depending on the output type of the sensor, connect the TX/RX pins to a microcontroller for UART communication, or the PWM/ANALOG pin for pulse width modulation or analog voltage output.

• Ensure the sensor is placed in an area with unrestricted airflow.
• Avoid exposure to high concentrations of dust or chemicals that may damage the sensor.
• Calibrate the sensor periodically to maintain accuracy.
• Implement proper filtering and averaging techniques to reduce noise in the sensor output.

• Inaccurate Readings: Ensure the sensor is calibrated correctly and not obstructed by dust or debris.
• No Output Signal: Check the power supply and connections to the sensor. Ensure the correct pins are used for data output.

• Regularly clean the sensor's inlet to prevent blockages.
• Verify the power supply is stable and within the specified voltage range.
• If using UART communication, ensure the baud rate and data format match the sensor's specifications.

• Q: How often should the PM2.5 sensor be calibrated?
  • A: Calibration frequency depends on usage, but typically once every six months is recommended.
• Q: Can the sensor be used outdoors?
  • A: Yes, but it should be protected from direct rain and extreme weather conditions.

// Example code for interfacing a PM2.5 sensor with an Arduino UNO
#include <SoftwareSerial.h>

SoftwareSerial pmSerial(10, 11); // RX, TX

void setup() {
  Serial.begin(9600);
  pmSerial.begin(9600); // Initialize the software serial port
  Serial.println("PM2.5 Sensor reading started");
}

void loop() {
  if (pmSerial.available()) {
    // Read data from the sensor
    int pmValue = pmSerial.read();
    // Output the PM2.5 value
    Serial.print("PM2.5 Concentration: ");
    Serial.print(pmValue);
    Serial.println(" µg/m³");
  }
  delay(1000); // Wait for a second for the next reading
}

Note: The example code provided is a basic illustration for reading data from a PM2.5 sensor with a UART interface. The actual implementation may vary based on the specific sensor model and its communication protocol. Always refer to the sensor's datasheet for precise programming and interfacing instructions.