We spend over 90% of our time indoors, where the amount of CO2 we exhale has a significant impact on our health and well-being. High CO2 concentrations not only lead to tiredness, headaches and can cause dizziness, they are also a good indicator of when the distribution of aerosols in the air exceeds a value that is more conducive to the spread of coronaviruses or mycobacterium tuberculosis. Ventilation and resulting low CO2 concentration in the air reduces the risk of infection.

Exposure to a high CO2 concentration can produce a variety of health effects. These may include headaches, dizziness, restlessness, a tingling or pins or needles feeling, difficulty breathing, sweating, tiredness, increased heart rate, elevated blood pressure, coma, asphyxia, and convulsions.

What is it?

A Wifi sensor that measures temperature, humidity, barometric air pressure, and carbon dioxide content in the ambient air.

Features:

• SenseAir S8 CO2 Sensor (carbon dioxide gas sensor)
• Optional Temperature / Humidity / Barometric Air Pressure sensor
• ESP8285 Wifi Chip that serves the sensor data directly to a homeassistant, MQTT, HTTP, no additional gateway needed.
• CH340 USB to UART chip for flashing and programming
• 4 Buttons: 1 Mode (set flashing/programming mode), Reset, IO_5 and IO_14 are free programmable i.e. for sensor calibration or turn on/off the indicator LED
• TeHyBug Universal sensor connector to extend the device with more sensors, like temperature, humidity, barometric air pressure, UV Light, or Luminance
• WS2812B indicator LED, controlled with IO_12, for indicating the Air Quality i.e. green=good, yellow=acceptable, red=bad
• 4Pin Audio Jack connector to extend the board with additional TeHyBug Universal sensors

CO2 Sensor Specs

• Measurement range: 400 to 2,000 ppm (0 to 10,000 ppm extended)
• Operation temperature: 0 to 50°C
• Accuracy: ± 70 ppm ± 3% of reading at 5 to 30°C, 20-70%RH
• Can be easily calibrated manually

What do you get?

You will get a ready-to-use, fully assembled device, that you will need to flash with the desired smart home firmware. Check the documentation link for the EspHome configuration.

How to flash?

It is easy to flash the module since it has an USBtoUart chip on board. You can use Arduino, Platformio, and EspHome, or other tools to upload your firmware to the board. Hold the Mode button, hit the Reset button, and release the Mode button to put the ESP8285 Module into the flashing mode.

Example of HomeAssistant integration

The HomeAssistant support is included in the preinstalled software

A similar device with the same features but a different sensor and a smaller size is available in my Tindie store: https://www.tindie.com/products/27887/

Please also check my store for other smart home devices.