User Manual

MQ-7 Gas Sensor User Manual Waveshare
1
MQ-7 Gas Sensor User Manual
1. Features
Sensitive gas
Carbon monoxide
Boost converter chip
PT1301
Operating voltage
2.5V-5.0V
Dimensions
40.0mm*21.0mm
Fixing hole size
2.0mm
Operating principle:
MQ-7 gas sensor applies SnO2 which has a lower conductivity in the clear air
as a gas-sensing material. In an atmosphere where there may be carbon
monoxide in a certain density, the conductivity of the gas sensor raises along
with the concentration of carbon monoxide increases.
2. Applications
This module can be applied to household and industrial gas leakage alarm,
portable gas detecting device, etc.
3. Interfaces
Pin No.
Symbol
Descriptions
1
DOUT
Digital output
2
AOUT
Analog output
3
GND
Power ground
4
VCC
Positive power
supply (2.5V-5.0V)
4. How to use
We will illustrate the usage of the module with an example of carbon
monoxide detection by connecting a development board.
① Download the relative codes to the development board.
② Connect the development board to a PC via a serial wire and the
module to the development board. Then, power up the development
board and start the serial debugging software.
Here is the configuration of the connection between the module and the
development board.
Port
STM32 MUC pin
DOUT
GPIOA.4
AOUT
GPIOA.6
GND
GND
VCC
3.3V