This text describes a carbon dioxide sensor module that employs infrared (IR) radiation to detect CO2 levels in the air. It’s ideal for projects needing a broad range of CO2 detection, such as monitoring indoor air quality, landfills, process control, and horticulture in controlled environments.

The module features an MG-811 sensor, a metal oxide sensor that requires heating to a specific temperature. This heating causes CO2 molecules to disengage from the air and be absorbed by the sensor. The MG-811 is more responsive to CO2 than to alcohol or CO, and its output voltage rises with increasing CO2 levels.

Suitable for use in greenhouses and medical applications, the sensor module emits an analog signal that inversely correlates with CO2 concentration. It also provides a digital output pin with TTL output. The integrated potentiometer allows for the adjustment of the digital output threshold. Upon reaching this threshold, the sensor’s LED will activate, and the digital pin will emit a HIGH voltage signal.

Pinout:

1. VCC: 6V (You can use a 4 AA battery holder for this ).
2. AOUT: Analog Output (voltage decreases as CO2 Levels increase).
3. DOUT: Digital Output that goes HIGH when the threshold is reached (set the threshold by turning the onboard potentiometer).
4. GND: 0V.

Features:

1. Wide detecting scope.
2. High sensitivity & stability.
3. Simple drive circuit.
4. Digital output: Active low (When it outputs a low-level signal, the indicator LED will be on)
5. Analog output: Two Range Options: 0 to 2V or 0V to 4V. The default is 0V to 2V DC.
6. Compatible with Arduino & Raspberry Pi (for use on analog output with Raspberry Pi you will need an Analog to Digital Converter Chip).

Specifications: