Integrate the Carbon Dioxide (CO2) Module

Integrate the Carbon Dioxide (CO2) Module

Enhance your Everything Presence Lite with CO₂ monitoring.

Install the CO₂ Sensor

What you need

  • Everything Presence Lite (powered off)

  • CO₂ sensor module

Identify GPIO Pins

  1. Locate the GPIO pins in the bottom corner of the Lite board.

    • The layout may vary depending on your board revision.

  2. Align the CO₂ sensor module with the pins, ensuring:

    • 3.3V on the sensor matches 3.3V on the board.

    • GND (Ground) on the sensor matches GND on the board.

  3. Firmly push the CO₂ module onto the GPIO pins.

Install the CO₂ Firmware

To enable CO₂ monitoring, install the CO₂ firmware version on Everything Presence Lite.

  1. Using the flasher below select the following settings.

  2. Choose LD2450 as the default mmWave sensor.

  3. Select the CO₂ module.

  4. Choose between:

    • Bluetooth firmware (if you need Bluetooth features).

    • Non-Bluetooth firmware (if Bluetooth is not required).

  5. Click Connect and follow the on-screen instructions.

Link to install CO2 sensor

Verify CO₂ Sensor in Home Assistant

Once the firmware update is complete, the CO₂ sensor should automatically appear as an entity in Home Assistant.

Using the CO₂ Sensor

The CO₂ sensor measures carbon dioxide concentration in parts per million (ppm). Here's what typical readings mean:

CO₂ Level

Meaning

400-450 ppm

Fresh outdoor air

450-700 ppm

Good indoor air quality

700-1000 ppm

Acceptable, consider ventilation

1000-2000 ppm

Poor air quality, open windows

2000+ ppm

Significantly elevated, improve ventilation immediately

Tip: CO₂ levels are a great indicator of ventilation quality. Use automations to trigger fans or send notifications when levels exceed your preferred threshold.

Calibrating the CO₂ Sensor

The SCD40 CO₂ sensor is factory-calibrated but may need recalibration over time for best accuracy.

When to Calibrate

  • After installing the sensor for the first time

  • If readings seem consistently off by more than 50-100 ppm

  • After the sensor has been stored for a long time

  • Periodically (every 6-12 months) for best accuracy

How to Calibrate

  1. Place the sensor in fresh outdoor air, or near an open window with good airflow

  2. Wait at least 5 minutes for the sensor to stabilize

  3. In Home Assistant, find the Calibrate CO2 button entity

  4. Press the button to calibrate to 419 ppm (current atmospheric CO₂ average)

Important: The sensor must be exposed to fresh air during calibration. Indoor air typically has higher CO₂ levels due to human respiration.