LinkGear CO2 Ampel for Home Assistant: New Stable Release

Good indoor air quality matters at home, in classrooms, in offices, and in shared spaces. The LinkGear

CO2 Ampel for Home Assistant is designed to make rising CO2 levels visible immediately, not just as numbers on a dashboard, but directly in the room through a clear traffic-light-style LED display. With local ESPHome integration, reliable CO2 sensing, and direct Home Assistant support, it offers a practical way to improve ventilation awareness without relying on cloud services.

The new stable release builds on the proven functionality of the previous version and adds a range of practical improvements. The result is a more polished, more configurable, and more automation-friendly CO2 Ampel while keeping the core idea simple: make air quality easy to understand at a glance.

What Is the LinkGear CO2 Ampel?
The LinkGear CO2 Ampel is an ESPHome-based CO2 monitor built for Home Assistant. It uses the Sensirion SCD41 to measure carbon dioxide levels and shows the result with onboard LEDs in a familiar green-yellow-orange-red scheme. That makes it easy to see when fresh air is needed, whether in a living room, office, classroom, or workshop.

Alongside CO2 measurement, the device also provides additional environmental data such as temperature, humidity, pressure, and ambient light, making it a useful part of a broader smart home or smart building setup.

What’s New in the Stable Release?
The latest stable release focuses on real-world usability.

Smarter LED Control
The LED behavior is now more flexible and better suited to everyday environments. Users can adjust brightness, use smoother color transitions, and benefit from ambient-light-based night mode behavior. This makes the device more comfortable in darker rooms and more adaptable in spaces where a permanently bright status light would be distracting.

There is also more flexibility for users who want to integrate the LEDs into custom Home Assistant automations, by being able to detach the LEDs from being controlled by the on-board configuration through a single click.

Better Daily Experience
The device now behaves more cleanly during startup and offers a more refined user experience overall. The goal is straightforward: better feedback, cleaner behavior, and improved usability in daily operation.

Improved Alerts and Automation Options

The stable release extends buzzer and automation capabilities, making it easier to use the CO2 Ampel in notification and ventilation workflows inside Home Assistant.

Existing integrations remain supported, which is especially important for users who already rely on dashboards, scripts, or automations built around buzzer actions.

More Diagnostics in Home Assistant
Additional diagnostic entities make the device easier to monitor and manage directly in Home Assistant. This improves visibility into connectivity, status, and general device health.

How to Upgrade or Re-Flash
Existing users can move to the new stable release in two ways.

For the simplest update path, the web flasher at flash.linkgear.net can be used to re-flash the device. This requires re-adoption in Home Assistance.

Users who already have an adopted device managed through ESPHome can also copy over the current config directly from GitHub and update it that way:
LinkGear CO2 Ampel cv2 config on GitHub

This gives both new users and existing ESPHome users a straightforward upgrade path.

An Improved Hardware Version Is Coming Soon

The upcoming version is intended to further improve the platform with hardware refinements and an even better overall user experience.

Join the Community
If you want updates, early information about the upcoming hardware release, setup help, or direct exchange with other users, join the community on Discord:

Join the LinkGear community on Discord

Why It Fits Home Assistant So Well
Many CO2 monitors can measure air quality, but fewer are designed around local control, open integration, and visible room feedback. That is where the LinkGear CO2 Ampel stands out.

It gives Home Assistant users:

• local ESPHome integration
• no cloud dependency
• immediate visual CO2 feedback
• flexible automation support
• useful environmental and diagnostic data in one device

That combination makes it a strong fit for smart homes, offices, schools, and anyone who wants indoor air quality to be both measurable and actionable.

Final Thoughts
The new stable release makes the LinkGear CO2 Ampel more refined, more configurable, and more useful in everyday Home Assistant setups. It keeps the simplicity that made the device practical in the first place while improving flexibility, comfort, and integration.

And with an improved hardware version coming soon, pre-orders on the horizon, and a simple upgrade path for existing users, this is a good moment to take a closer look at the LinkGear CO2 Ampel and join the growing community around it.

Changelog

• Added a boot animation so device startup is clearer.
• Improved CO2 LED behavior with smoother color transitions from good to poor air quality.
• Added adjustable LED brightness.
• Added optional night mode using the ambient light sensor, so LEDs can dim or turn off in dark rooms.
• Added a configurable CO2 alarm that can trigger the buzzer when values go outside a chosen range.
• Added a manual CO2 calibration button.
• Added more diagnostic entities, including uptime, Wi-Fi signal, IP address, and Wi-Fi SSID.
• Added the option to disable the built-in LED CO2 logic for manual control via Home Assistant.
• Improved API behavior and kept buzzer action compatibility with CV1-based integrations.