Overview
The SCD41-2HA module measures CO₂ (carbon dioxide) is designed for direct integration into Home Assistant using the ESPHome integration, it is based on an ESP8266 D1 Mini microcontroller.
It is based on the professional-grade Sensirion SCD41 sensor, a high-precision photoacoustic NDIR CO₂ sensor well suited for indoor air quality monitoring.
The SCD41-2HA module comes fully assembled in a compact 56 × 58 × 28 mm enclosure and requires no hardware configuration.
Technical Specifications
Sensor: Sensirion SCD41
Technology: Photoacoustic NDIR
CO₂ Measurement Range: 400 to 5000 ppm
CO₂ Accuracy: ±50 ppm – ±2.5% of measured value
Additional Measurements:
Relative humidity
Temperature
Connectivity: Wi-Fi
Integration: Native Home Assistant support via ESPHome integration
Power Supply: 5 V via USB Type-C connector
The temperature reading is for indication only, as the sensor is affected by internal heat buildup.
Home Assistant Integration
Installation steps:
Plug the module into a 5 V USB-C power supply.
Connect it to your Wi-Fi network.
It will be automatically detected, or you you will need to add it via the ESPHome integration.
The CO₂, humidity, and temperature entities will appear automatically in Home Assistant.
Typical Use Cases
Indoor air quality monitoring
Automating ventilation or air purifiers based on CO₂ levels
Displaying live air quality data on Home Assistant dashboards
Extensions and Options
In addition to CO₂ measurement, you may also find it useful to monitor:
VOC with the SGP40 sensor (10$)
Temperature, humidity, and pressure with the combined AHT20 + BMP280 sensor (6$)
A BH1750 light sensor, although this is less relevant for air quality (5$)
These are available as optional add-ons.
If you’d like to integrate additional sensors or features (such as a buzzer, button, or LEDs), feel free to contact me.
Related Product
If you also wish to measure fine particulate matter (PM), check out my SPS30-2HA module here:
SPS30-2HA
Price : 32 $
