CO Click carries the MQ-7 gas sensor with high sensitivity to carbon monoxide. The Click is designed to run on a 5V power supply only. It communicates with the target microcontroller over the AN pin on the mikroBUS™ line.

The board also features a calibration potentiometer, a mikroBUS™ host socket, two jumpers and a power indicator LED.

MQ-7 sensor features

The MQ-7 sensor has high sensitivity to carbon monoxide. The gas sensing layer on the sensor unit is made of Tin dioxide (SnO2), which has lower conductivity in clean air. The conductivity increases as the levels of Carbon monoxide rise. The detection range of the sensor is 20ppm-2000ppm of CO.

Calibrating the sensor

To calibrate the sensor for the environment you’ll be using it in, CO Click has a small potentiometer that allows you to adjust the Load Resistance of the sensor circuit. For precise calibration, the sensor needs to preheat (once powered up, it takes 48h to reach the right temperature).

Carbon monoxide detection

Carbon monoxide gas sensors are used to detect the presence of that gas and prevent carbon monoxide poisoning.

Since carbon monoxide has no smell or color, humans cannot detect it. In high concentrations, it can be lethal.

• Interface: Analog
• Compatibility: mikroBUS™
• Dimensions: 42.9 x 25.4mm
• Input Voltage: 3.3V, 5V

• MQ-7 Datasheet
• mikroSDK
• GitHub