Mikroe Air Quality Click (Mikroe-1630) – MQ-135 Gas Sensor Board, Analog Output, Range: 10 to 1000ppm

The board uses an MQ-135 sensor, which is sensitive to a variety of gases that impact air quality. Its primary targets include ammonia (NH3), nitrogen oxides (NOx), benzene, smoke, and carbon dioxide (CO2). It provides a general air quality indicator rather than a precise measurement of a single gas.

The board provides a single analog voltage output. Connect the AN pin from the mikroBUS header to an Analog-to-Digital Converter (ADC) input pin on your microcontroller (e.g., Arduino, Raspberry Pi, STM32). The output voltage will vary with gas concentration, and you can read it using standard ADC libraries. The board also requires 5V (or 3.3V) and GND connections via the mikroBUS socket.

The potentiometer adjusts the load resistance of the sensor circuit, which is crucial for calibration. You can use it to set the sensor's baseline output voltage in clean air or to fine-tune its sensitivity for a specific target gas or application environment, ensuring more reliable and accurate readings.

Yes, the board is designed for dual voltage operation. You can power it with either 3.3V or 5V DC. The analog output signal will be ratiometric to the supply voltage, meaning the output range scales with VCC. Ensure your microcontroller's ADC reference matches the supply voltage used for accurate measurements.