Setup instructions for adding your Serin Controller to Google Home, Amazon Alexa, or SmartThings using the Matter-compatible firmware, labeled Google Home, Alexa & SmartThings in the flash tool. The app supplies Wi-Fi credentials during pairing; there is no separate setup-hotspot step for a fresh installation.

Using a different build? Choose the matching guide.

Before you start

• A compatible indoor unit and controller with this guide's firmware installed. If you have not flashed it yet, use the flash tool on a computer with a USB-C data cable.
• A 2.4 GHz home Wi-Fi network and its password.
• Your smart-home app and a compatible hub. Check the requirements in your app's section below.
• IPv6 enabled on your home network, and your phone near the controller for Bluetooth commissioning.

Beta firmware. This build is newer and less tested than the ESPHome and HomeKit builds. It is free to install, its source is not published, and it is not Matter-certified. Your app may require confirmation of an uncertified accessory.

1 Install the controller

Follow the installation guide to connect the CN105 cable, position the controller, and replace the cover before restoring power.

Before moving on: The cover is back on and power is restored. If you paired at the bench, check that the controller reconnects to your home network.

2 Add the Matter thermostat

Already paired in your app? Check control.

1. Stand near the controller with your phone. Begin adding a device in your app.
2. Scan the Matter QR code or enter its 11-digit pairing code. The flash tool displays it after installation and saves it in the same browser. The controller also prints it to the serial console at startup.
3. Follow the app's prompts to supply your 2.4 GHz Wi-Fi network. The credentials transfer over Bluetooth. Confirm any uncertified-accessory notice.
4. Assign the thermostat to its room. Once added, the hub controls the controller over the local network.

Google Home

You need the Google Home app and a compatible Google or Nest hub. Check Google's current Matter requirements. In Google Home, begin adding a device and use the Matter pairing-code path. Scan the controller's code, follow the Wi-Fi and accessory prompts, and select its room.

Amazon Alexa

You need the Alexa app and a compatible Echo or eero device. Check Amazon's supported devices. Begin adding a device in Alexa, choose the Matter pairing-code path, and scan or enter the controller's code. Follow the prompts and assign the thermostat to a room. No custom Alexa skill is required.

SmartThings

You need the SmartThings app and a compatible Matter hub. Check SmartThings' Matter guidance. Add a Matter device, scan the pairing code, and complete the network and room prompts.

Already using this build with Apple Home or Home Assistant? Their Matter add-device flows use the same Matter code; it is different from a HomeKit setup code. Follow the requirements of that platform. For a new installation, see the firmware comparison.

For pairing timeouts, a missing code, or an unavailable thermostat, see Matter troubleshooting.

Check: The controller appears as a thermostat in your app. Next, check its connection to the indoor unit.

3 Check that the unit responds

1. Open the thermostat in your app and check that it reports the room temperature.
2. Change the mode or target temperature and confirm the indoor unit responds. Check that the app and controller report the resulting state.
3. If the app is connected but commands have no effect, use the CN105 checks. App pairing alone does not prove the cable's data connection works.

Setup is complete when the app shows a current room temperature and the indoor unit responds to your commands.

Once control works, use the web interface for additional controls, or follow the room sensor and maintenance guides. For another indoor unit, repeat the process with its own controller and a unique name.