The MQ3 Gas Sensor module is useful for gas leakage detection (in home and industry). It is suitable for detecting Alcohol, Benzine, CH4, Hexane, LPG, CO. Due to its high sensitivity and fast response time, measurements can be taken as soon as possible. The sensitivity can be adjusted by using the potentiometer on the module.
I connected my sensor as follows
Linkit Connection | Gas Sensor |
---|---|
3v3 | VCC |
GND | GND |
NC | D0 |
Analog A0 | A0 |
Code
This is a basic example, the sensor takes time to ‘heat up’ , so that should be taken into consideration. Also the correlation between gas and the value returned is not a linear value.
You can see this in the specs later on
[codesyntax lang=”cpp”]
void setup() { Serial.begin(9600); } void loop() { float sensorVoltage; float sensorValue; sensorValue = analogRead(A0); sensorVoltage = sensorValue/1024*3.3; Serial.print("sensor voltage = "); Serial.print(sensorVoltage); Serial.println(" V"); delay(1000); }
[/codesyntax]
Results
I saw the following results in the serial monitor
sensor voltage = 1.83 V
sensor voltage = 1.78 V
sensor voltage = 1.74 V
sensor voltage = 1.70 V
sensor voltage = 1.66 V
sensor voltage = 1.63 V
sensor voltage = 1.59 V
sensor voltage = 1.56 V
Links
Mq-3 Gas sensor specs
MQ-3 Alcohol Ethanol Sensor Breath Gas Ethanol Detection