This course is useful for all Atal Tinkering Lab students.

1. MQ-4 SENSOR
Interface with Arduino UNO

2. MQ-4 Sensor Pins (From Left)
Two Pins from Left
A0 (Analog
Output) and D0
(Digital Output)
01
GnD for Ground
or Negative
02
VCC for 5V Power
Supply
03

3. MQ-4 Sensor with Arduino UNO
In the schematic,
there are two resistors
connected to the
Arduino digital pins
and LEDs. The
resistance is 220 Ohm

4. MQ-4 Sensor with Arduino UNO
As a natural gas sensor, the MQ-4 Natural Gas Sensor is a fast and reliable
sensor with a high sensitivity to natural gas and methane, also good sensitivity
to propane and butane. This natural gas sensor has a long life and low cost and
is widely used for gas leak detection. At the same time, two LED lights are used
in the project to display the gas concentration:
•Green light: it means the natural gas concentration is below the critical value.
•Red light: alert! The natural gas concentration has exceeded the critical value.

5. MQ-4 Gas Sensor Pins
The MQ-4Arduino sensor has four pins:
• Positive VCC (+5V)
• Ground GND
• Digital output
• Analog output