M5Stack MQ-5 Gas Unit (STM32G030)

M5Stack MQ-5 Combustible Gas Sensor Unit

The M5Stack MQ-5 Gas Unit combines an MQ-5 semiconductor gas sensor with an STM32G030F6P6 controller for combustible-gas monitoring experiments and embedded sensing systems. It communicates through I2C and exposes processed information such as sensor voltage, ADC values, firmware information, and internal temperature-related data to the host.

The installed MQ-5 sensor is intended for combustible gases including methane and LPG-related gases. The product specification lists a 300–10000ppm detection range for methane and propane. Gas-sensor response depends strongly on warm-up state, calibration, temperature, humidity, sensor aging, gas mixture, airflow, and installation conditions.

Choose Continuous or Intermittent Heating

The unit supports continuous and intermittent heating modes. Continuous heating brings the sensing element into operation more quickly and is specified at about 188.89mA from 5.05V under the product test condition. Intermittent heating can reduce average energy use when the application can tolerate a defined heating and sampling cycle.

I2C Data Access at Configurable Address

The default communication address is 0x11 and can be configured. This makes the unit easier to combine with other I2C peripherals, but the final bus still needs an address plan, suitable pull-ups, and appropriate cable length.

Plan Calibration and Baseline Management

MQ-series sensors are not plug-and-play precision analyzers. Establish a repeatable warm-up process, record baseline behavior, calibrate against the target environment when quantitative thresholds matter, and periodically verify the response. Avoid interpreting one raw ADC threshold as a universal gas concentration across all installations.

Important Safety Limitation

This development sensor should not be the sole life-safety gas alarm. For homes, workplaces, or hazardous areas where a missed alarm could cause injury or death, use appropriately certified detection and alarm equipment that meets local regulations. The MQ-5 Unit can support prototypes, trend monitoring, research, and supplementary sensing when the system is engineered for the actual risk.

Technical setup details are available in the M5Stack MQ Unit documentation.