Unit CO2/CO2L Home Assistant Integration

This tutorial will introduce how to use the Unit CO2/CO2L sensor to integrate into Home Assistant, achieving real-time monitoring of carbon dioxide, temperature, and humidity.

1. Preparation

Environment Setup

1. Install Home Assistant by following the official Home Assistant documentation.
2. Install the ESPHome Device Builder add-on by following the official ESPHome documentation.
3. Refer to the following resources:

• SCD4x Datasheet
• SCD4X CO2 and Temperature/Humidity Sensor

Hardware Products

• Unit CO2
• Unit CO2L
• A compatible controller (such as an Atom, Stamp, Stick, Core, or Basic series device)

2. Modify Configuration

The I²C component needs to be enabled in the ESPHome configuration:

# Example configuration entry for ESP32
i2c:
  sda: GPIOXX
  scl: GPIOXX
  scan: true

The GPIO pins here vary depending on the main controller used. For example, using Atom Lite as the controller:

# I2C Bus on Grove Port (HY2.0-4P)
i2c:
  sda: GPIO26
  scl: GPIO32

Example configuration for Unit CO2/CO2L:

sensor:
  - platform: scd4x
    co2:
      name: "CO2"
    temperature:
      name: "Temperature"
    humidity:
      name: "Humidity"

3. Getting Started

Once added to the Dashboard, you can view the sensor data in Home Assistant.

4. Related Video