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MQ Gas Sensors – Measuring gas

When you have initialized the sensor (either Qwiic or Native), we can read the sensor measurements in the loop() function:

void loop()
{
  mq131.update();      // Update data, read voltage level from sensor
  Serial.println("O3: " + String(mq131.readSensor())+"ppb"); // Print the readings to the serial monitor
  delay(500);        // Sampling frequency
}
Sensor reading on serial monitor
Sensor reading on serial monitor

mq131.update()

Updates the data and reads the sensor's voltage

Returns value: None

mq131.readSensor()

Calculates gas concentration via the regression method and returns it

Returns value: Float value, gas concentration in ppm, ppb or mg/L, depending on the sensor

Full example​

MQ-131-Qwiic.ino

Gas measurement example for the Qwiic version of MQ131 sensor
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While this example covered the MQ131, the process is practically identical for every sensor, Qwiic and Native. We encourage you to check out all the examples here