Carbon Dioxide Alert

Carbon dioxide warning notification on iPhone

In many smart home scenarios, it's not enough to know a value - you want to be notified as soon as it crosses a critical limit. A typical example is air quality: if the CO2 level gets too high, you should be reminded to ventilate the room. This step-by-step guide shows how to trigger a notification when a CO2 threshold of 1000 ppm is exceeded.

Start Event

First, add the start event for your workflow. In this case, the workflow is triggered when the CO2 value of a sensor exceeds a defined threshold. Select "Accessory Value" and choose the corresponding CO2 characteristic. Set the trigger to activate when the CO2 level rises above 1000 ppm.

Steps

Add the Step "Get Accessory State"

Add the "Get Accessory State" step to retrieve the current CO2 level from the sensor. The value is stored in the variable P1 by default, which you can rename if needed. We rename it to "CARBONDIOXIDE" for clarity.

Add the Step "Notification"

Next, add the "Notification" step. Use "High CO2 Level Detected" as the title. In the text field, enter:

"The CO2 level is $CARBONDIOXIDE. Please ventilate the room to improve air quality."

The dollar sign ensures that the variable "CARBONDIOXIDE" is inserted dynamically, replacing the placeholder with the actual sensor value.

Notification workflow configuration with dynamic value

Final Overview

As soon as the CO2 concentration exceeds 1000 ppm, you'll receive a notification including the current value and a clear reminder to air out the room. Automatic execution of this workflow requires a device with Controller Hub enabled.