9531 – MQ-5 Gas Sensor/en

Documentation notice: This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

Summary

The MQ-5 uses tin dioxide (SnO2) as the sensitive material. Conductivity rises with the concentration of flammable gases such as butane, propane and methane. The module provides an analog output (AOUT) and a digital threshold output (DOUT).

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Technical overview

Operating voltage: 2.5 V to 5.0 V.
Module size: 40.0 mm × 21.0 mm; mounting hole diameter 2.0 mm.
Pins: VCC, GND, AOUT (analog), DOUT (digital).
Raspberry Pi Pico wiring: VCC → 3.3 V, GND → GND, AOUT → GP26, DOUT → GP22.
STM32F103RBT6 wiring: VCC → 3.3 V, GND → GND, AOUT → PA6, DOUT → PA4.
Arduino UNO wiring: VCC → 5 V, GND → GND, AOUT → A0, DOUT → D2.
Example projects are provided for Pico (C/C++ and MicroPython), STM32 (HAL library, Keil) and Arduino IDE.
The module needs about one minute of preheat time so the sensitive material reaches operating temperature.

Commands and examples – verify before use:

sudo apt-get install p7zip-full
cd ~
sudo wget https://files.waveshare.com/upload/6/63/MQ-5-Gas-Sensor-code.7z
7z x MQ-5-Gas-Sensor-code.7z -o./MQ-5-Gas-Sensor-code
cd ~/MQ-5-Gas-Sensor-code/Pico/c/
cmake ..
make -j9
cp main.uf2 /media/pi/RPI-RP2/

Notes and version constraints

The provided examples are based on fixed boards (Pico, STM32F103RB, Arduino UNO). For other boards, connections and code may need adaptation.
For the Pico, suitable firmware must be flashed first; the exact firmware version depends on the example archive.
The exact threshold setting of the digital output is not described in the source; please verify against the datasheet.
No calibration, accuracy or certification data are given in the source; do not state values that are not present.

Source and revision record

MQ-5 Gas Sensor - Waveshare Wiki
Source revision: 68897
Captured: 2026-08-29T09:42:28+00:00
SHA-256: 386a9d43b360c7be35d137f839960a2f98c4405552bb9629a004c07a869c9822