CTRL ONE

The complete smart room controller

The CTRL ONE brings together everything you need to understand and control your space in one beautifully simple device. A smart touch panel, information display, and air quality monitor designed to fit seamlessly into your home, office, or garage without a cluttered app or complicated setup in sight.

The CTRL ONE is a touch panel, information display and air quality monitor, with a flexible add-on system to make a fully-featured smart thermostat. With the integrated, factory-calibrated SCD40 temperature, humidity and CO2 sensor, the CTRL ONE is able to provide minute-by-minute insights into the most important stats in any room.

It's an open, hackable device. Create a configuration that works perfectly for your home powered by ESPHome, with full technical documentation and open source code to tinker with. The ESPHome ecosystem has you covered, with the Device Builder making it a breeze to build your solution through an easy to use web interface.

Always know what's in the air

At the heart of the CTRL ONE is a factory-calibrated SCD40 sensor, continuously tracking temperature, humidity, and CO2 levels. The corner cutout design physically separates it from the heat-generating internals, while shielding it from draughts and direct sunlight - making every reading genuinely accurate, not just close enough. Out of the box it samples every 30 seconds (plenty for thermostat use), but push it to every 5 seconds if your use case demands it.

The CTRL ONE will highlight if the humidity or CO2 levels start getting uncomfortable. Extend it further by creating Automations in Home Assistant to turn on your ventilation system, or just a notification to tell you to open a window.

Simple design, premium look

The shape of the CTRL ONE is designed to put the bezel and display front and centre. The edges slant away to give it a "floating" look, while giving the sensor maximum exposure to the air in the room. It currently comes in two bezel options:

Glossy White: A classic white look, more closely matching the display and making the device unobtrusive. Great for bedrooms, bathrooms and other places where you want it to stay in the background.

Natural Oak: Made of real 1mm thick white oak, turn your CTRL ONE into a statement piece that invites you to interact with it. Great for living rooms and hallways. Every bezel will have its own unique wood grain and texture, so yours won't look exactly the same as the one pictured. It'll be unique to you!

Thermostat, air quality monitor, or whatever you choose

The CTRL ONE is what you make of it. It's a platform designed to be owned 100% by you, no cloud or subscription strings attached. It's a thermostat, it's an air quality sensor, or it's simply an elegant, compact ePaper touchscreen display that's starting point of your next electronics DIY project; the choice is yours.

Heating built with ESPHome, for Home Assistant

Finally, a heating solution that's Home Assistant native. With no cloud or separate app, connect the CTRL ONE to your Home Assistant setup and use the full power of Automations and Blueprints to set custom heating schedules based on anything you can imagine. Build solutions that use your existing sensors to change the heating depending on whether you're at home, the solar panels are generating power or what the weather looks like today.

Don't want to mess with your heating system? Use the CTRL ONE's accurate sensors to keep an eye on the quality of the air in the room, while providing quick access to triggering automations and showing important data. Pro Tip: when combined with a weather source or outside sensor via Home Assistant, it can make great little weather station display.

A thermostat for all systems

With the 24VAC thermostat module (sold separately), the CTRL ONE is also able to fully replace many common wired thermostats found in houses and apartments. Through the add-on system, support for more heating systems will be added in the future.

Add-ons for so much more

With a standard 8-pin header on the back, extend the functionality with the CTRL ONE with one of the official modules, or use the breakout board add-on to make something of your own. With GPIO, i2c and up to 28V power input supported, you can make the CTRL ONE fit your space, not the other way around.

Information at a glance, on an ePaper display

ePaper displays have been quietly flooding into your everyday life, from ebook readers, to the price labels in the supermarket. Did you notice? That's the same reason it was chosen for the CTRL ONE; it shows you the information you need at a glance on a paper-like display, while melting into the background.

The crisp 300 × 400 ePaper touchscreen is easy on the eyes by design. It shows you what matters without demanding your attention; and when you need it, a tap brings the backlight to life, automatically adjusting its brightness so it's never too bright at night and stays off during the day.

Want to do more with it? As it's running ESPHome, all this functionality can be modified to your heart's content. If you don't like it, change it, and make it yours.

The power of Open Source

The source code is fully open source, and the configuration is designed to be tinkered with. Make the CTRL ONE your own, starting with the pre-made widgets that fit onto a 4x6 grid that can fetch data from Home Assistant. Use widgets such as buttons and sliders through the touchscreen to control lights, fans, curtains and more from one place - your phone stays in your pocket.

The power of the CTRL ONE comes from configuration; out of the box, it can only show you data from its own sensors. By adding your own widgets, you can bring together smart devices from across your home.

Built on a proven software platform

ESPHome's text-based configuration allows for the ultimate in flexibility, so you can integrate the CTRL ONE perfectly into your setup. New to ESPHome? No worries - the ESPHome Device Builder will automatically pick up your device when it's first connected to your WiFi, and it provides a graphical interface that explains how it all goes together.

Not just open software - open hardware

The CTRL ONE is made to be 3D printed. The mounting system is fully open for you to create your own custom mounts, placing the CTRL ONE in more places than we can think of. If the bezel is a little too plain for you, the original dimensions are available for you to make it your own.

Check out the source code

Don't take my word for it? Find all the available code on Codeberg, and check out our documentation on how to best make use of it.

Decide your placement

Wall-mounted, counter-standing, or tucked to the side of a cabinet — the CTRL ONE comes with mounting options to suit almost any space. And if none of them fit, the designs are freely available to 3D print and adapt however you like. Note that this device does not have a battery.

24VAC thermostat addon shown above sold separately.

The wall mount

With a passthrough hole in the center and a standard 60mm screw spacing, the wall mount can fixed to standard European wall cavities, either taking the place of a thermostat, wall socket or switch. Get a completely seamless install with no visible wires, connected to your existing heating system.

The 24VAC Thermostat Add-on powers the device through standard 24V AC heating system wiring, or purchase the break-out board to supply up to 28V DC power from an external power supply directly to the device.

The stand

The included stand places the CTRL ONE at a great angle to view from the entire room when placed on a counter or table. While the angle is fixed to keep things simple, if you don't like it, the code for the stand is available for you to decide the angle that works for you! Change the angle, and 3D print your own.

The stand is designed around the USB-C port, making the (not included) USB cable route neatly out of the back, and behind your furniture.

Make it your own

The CTRL ONE itself is made out of a combination of 3D printed & laser-cut parts. The standard wall mount is available in the Python code it was made in, along with STEP files for you to bring into your 3D modelling software of choice. Please share how you're using it on the r/elvinhome subreddit, and give others some inspiration!

What's in the box

• The CTRL ONE, in your choice of color (the white version is shown above)
• Rotatable wall mount, designed for a standard 60mm European recessed mount
• Backplate to go over the wall mount
• Portrait orientation stand for placing the CTRL ONE of a desk, shelf or other surface

The USB port is not accessible once wall mounted, so you'll either need the 24VAC thermostat add-on, or your own solution using the breakout add-on - both sold separately. USB cable & power supply not included.

As for the box itself - the packaging is designed to be small to fit in letterboxes and minimise waste. It's made entirely of cardboard and is fully recyclable. If ordering multiple, they are shipped inside their boxes in a recyclable plastic bag.

Tech Specs

Note - this early revision has a misprint on the add-on slot. "IO0" should read "IO1" as it uses GPIO1 on the ESP32. It does not affect functionality.