MQ-7 Smoke Gas Module Features
MQ series sensor uses a small heater inside with an electrochemical sensor in order to measure a different kinds of gas combinations. They can be calibrated, but, in order to do that, a known concentration of measured gas or gases is needed. Gas sensor is an indoor module and is used at room temperature. The MQ-7 sensor has high sensitivity to Carbon Monoxide and is able to detect the concentration of carbon monoxide in the air. The measurable concentration range of this sensor is between 20ppm to 2000ppm.
Note
After turning on the module, wait 2 minutes for the internal heater to warm up.
You can download the datasheet of this module here.
MQ-7 Smoke Gas Module Pinout
This sensor has 4 pins:
- 5V: Module power supply – 5 V
- GND: Ground
- DOUT: Digital output
- AOUT: analog output
You can see pinout of this module in the image below.
Required Materials
Hardware Components
Software Apps
Interfacing MQ-7 Sensor with Arduino
Step 1: Circuit
The following circuit shows how you should connect Arduino to MQ-7 module. Connect wires accordingly.
Step 2: Code
Upload the following code to your first Arduino.
/*
modified on Sep 28, 2020
Modified by MohammedDamirchi from Arduino Examples
Home
*/
// the setup routine runs once when you press reset:
void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
}
// the loop routine runs over and over again forever:
void loop() {
// read the input on analog pin 0:
int sensorValue = analogRead(A0);
// print out the value you read:
Serial.println(sensorValue);
delay(20);
}
After uploading the code, you can see the output in the serial monitor.
