Home Assistant offers a ton of ways to interact with your devices, from voice control to virtual buttons on dashboards.Sometimes, however, the most convenient option is to use a real physical button.The KeyBridge project allows you to use your old USB keyboards as smart home controllers, giving you a whole keyboard full of smart buttons.
Turn an old USB keyboard into a smart home controller Every key can trigger a different action Smart buttons can be really useful for triggering automations or controlling smart home devices.The problem is that they can be relatively expensive, and a single smart button may only offer a handful of different triggers.You may have looked wistfully at your old USB keyboard, wishing that you could use each of those keys as a dedicated smart home button.
The KeyBridge project aims to do exactly that.It can turn an old USB keyboard or macropad into a Home Assistant controller, without the need to plug the device into a computer.Instead of the computer interpreting the keypresses, KeyBridge does it, and passes the information about which key was pressed directly to Home Assistant.
This means that a cheap keyboard can become a smart home controller with dozens of different buttons.You could assign the L key to toggling the living room lights, have the down arrow close your blinds, or have the space bar pause your current media.While a full-size keyboard gives you the most options, it’s not always practical.
A smaller device such as a macropad or numeric keypad can also work with KeyBridge, giving you plenty of smart home controls in a smaller device.Related ESP32's biggest upgrade yet brings Wi-Fi 6 and Matter to DIY smart home projects The ESP32-S31 is ready for your more advanced DIY projects.Posts 2 By Jon Fingas A tiny ESP32 board makes the magic happen KeyBridge turns keypresses into Home Assistant actions Close KeyBridge is powered by a small circuit board built around an ESP32 microcontroller.
The key feature that the board offers is USB host functionality.A USB keyboard usually acts as a peripheral and sends information to a host computer that turns the keypresses into the relevant actions.KeyBridge uses an ESP32 with USB host capabilities to talk directly to the keyboard so that a computer isn’t needed.
Not every ESP32 supports USB host operation, so the project uses the ESP32-S2 in the current design, although you could achieve similar results with a compatible ESP32 and a USB breakout board.When a key is pressed, KeyBridge receives the input and shares it with Home Assistant via ESPHome.You can then use that input however you want, from triggering automations to controlling specific devices.
KeyBridge 2.0 has made the project even easier to use A smaller design with native ESPHome support The first version of KeyBridge appeared in 2025 and proved popular.The creator published the firmware and PCB design files, so it was possible to build your own KeyBridge device.After feedback from users, KeyBridge 2.0 is now available.
The two big changes are that the circuit board is more compact than the original KeyBridge, and that there’s now native ESPHome support.The smaller board makes it a little easier to hide KeyBridge away.If you’re mounting a keypad on a wall, for example, you don’t want a huge circuit board hanging out the bottom of it.
Native ESPHome support means that KeyBridge now uses ESPHome’s standard tools and talks directly to Home Assistant rather than using a separate firmware system.You can buy the components, build the device, flash the firmware, and then add the device to Home Assistant through ESPHome just as with other ESPHome devices.If you don't want to build your own KeyBridge, you can preorder ready-made KeyBridge 2.0 boards.
The board costs $35, and there’s an initial production run of 150 planned, but they’re not likely to ship until the end of the year.A keyboard controller can be really useful Numeric keypads also offer a lot of possibilities Using a USB keyboard to control your smart home might not seem like an obvious choice, but there's a lot you can do using one.Full-size keyboards give you more keys to play with, but smaller devices such as macropads and numeric keypads can be more practical.
For example, you could use a macropad as a desk controller to control the devices in your home office.One key could control your lights, another could power your desk fan, another could turn the smart bulb outside your office red to indicate that you’re on a call, and so on.A USB keypad can also make a great media controller.
You could use one key to play and pause your content, have a button to rewind the media by 30 seconds, another to turn on the subtitles, and so on.A USB keyboard could become a bedside controller.You could use it to control the main lights, to control each individual bedside lamp, to change the lighting scene, to adjust the heating, and even have a button to run your bedtime routine.
If you’ve ever regretted the lack of smart buttons in your smart home, KeyBridge can be a great way to turn an old device into a new controller.Sometimes you just want to push a button To my mind, a smart home should work using automation rather than relying on manual control.Sometimes, however, you need to control things manually, and while dashboards are fine, there’s nothing quite like pushing a real button.
KeyBridge makes that simple to do with hardware you may already own.
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