Sensirion SCD30 CO2 sensor MQTT gateway for Home Assistant

Overview

This gateway can be used to publish measurements SCD30 to mqtt.

It supports Home Assistant MQTT Discovery but can also be used without Home Assistant.

Only requirement is MQTT Broker to connect to.

Example usecase

Attach SCD30 to Raspberry Pi Zero W I2C bus and run this gateway to publish CO2, temperature and humidity to Home Assistant.

Configuration

Application is configure with environment variables

variable	required	default	description
SCD30_MQTT_URL	x		mqtt url, for example tcp://10.1.2.3:8883
SCD30_MQTT_USER			mqtt username
SCD30_MQTT_PASSWORD			mqtt password
SCD30_MQTT_CLIENT_ID		scd30	mqtt client id
SCD30_DEBUG		false	enable debug output, true/false
SCD30_ID		scd30	home assistant discovery id
SCD30_TEMP_OFFSET		150	temperature compensation offset
SCD30_NAME		SCD30	home assistant device name
SCD30_INTEVAL		50	measurement interval in seconds
SCD30_AUTOCAL		1	1 to enable automatic calibration, 0 to disable
SCD30_FORCECAL			CO2 ppm to force calibration to

Usage

For example with following script

#!/bin/sh

# Change to your real mqtt url
export MQTT_URL=tcp://localhost:8883

./scd30-mqtt

MQTT Topics used

• homeassistant/status subscribe to HA status changes
• scd30/id/co2 publish co2
• scd30/id/temperature publish temperature
• scd30/id/humidity publish humidity