MIKROE Air Quality Click is a simple solution for adding a high sensitivity sensor for detecting a variety of gases that impact air quality in homes and offices. It carries an MQ-135 sensor. The Click is designed to run on a 5V power supply. It communicates with the target microcontroller over the AN pin on the mikroBUS™ line.

Detecting gases

Air quality Click is suitable for detecting ammonia (NH3), nitrogen oxides (NOx) benzene, smoke, CO2 and other harmful or poisonous gases that impact air quality. The MQ-135 sensor unit has a sensor layer made of tin dioxide (SnO2), an inorganic compound which has lower conductivity in clean air than when polluting gases are present.

Calibration potentiometer

To calibrate Air quality Click for optimum performance, use the on-board potentiometer to adjust the load resistance on the sensor circuit.

• MQ-135 sensor
  • SnO2 gas sensing layer
• Interface: Analog
• Dimensions: 42.9 x 25.4mm
• Input Voltage: 3.3V, 5V
• Compatibility: mikroBUS™

• User Manual
• MQ-135 Datasheet
• GitHub