[Successful actual measurement] MQ-2 solution verification board

This project is used to verify the scheme verification design of LCSC’s gas detection module MQ-2 ( LCSC No. C99269 )

The gas-sensitive material used by the MQ-2 smoke sensor is tin dioxide (SnO2), which has low conductivity in clean air. When there is combustible gas in the environment where the smoke sensor is located, the conductivity of the smoke sensor increases as the concentration of combustible gas in the air increases. A simple circuit is used to convert the change in conductivity into an output signal corresponding to the gas concentration of the smoke sensor.

The MQ-2 gas smoke sensor has high sensitivity to liquefied gas, propane, and hydrogen, and is also ideal for detecting natural gas and other flammable vapors. This gas sensor can detect a variety of flammable gases and is a low-cost smoke sensor suitable for a variety of applications. ---------copy from datasheet

• This verification board has 1 digital output port, 1 analog output port, 1 potentiometer for adjusting digital output sensitivity, 1 power indicator light, and 1 digital output indicator light
• This verification board has VCC, GND, D0, and A0 input/output ports, and its attributes are

• Among them, the potentiometer R2 plays the role of adjusting the digital output sensitivity and can be adjusted according to the actual situation.
• Resistor R3 acts as a voltage divider and is not recommended to be too high or too low (I used 0Ω because it is out of stock and is not recommended for practical applications)
• U1 is LM393, its inverting part is used here

PCB blank board: actual soldering diagram: