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Choose supported hardware

Choose a NanoC6 or Atom S3 Lite from the parts list. For another board, check published firmware and Serin Link support; sharing a chip family does not guarantee compatibility.

Build and check the cable

Follow the CN105 wiring reference for connector orientation, pin mapping and assembly checks, or use a preassembled cable. Read the installation precautions before opening the unit.

USB and CN105 must not power the controller together. Keep the controller disconnected from the indoor unit while installing firmware over USB.

Install firmware and verify control

1. Choose the firmware for your app or Serin Link setup.
2. Use the browser flash tool if it offers your board.
3. Follow physical installation, then finish the applicable setup guide.
4. Confirm a current temperature and send a command that the indoor unit follows. If it does not respond, follow the CN105 checks.

Customize firmware

Use Customize ESPHome for standard boards. Other boards require their own board and UART configuration.

• CN105 ESPHome component: hardware, configuration and component development.
• HomeKit-compatible firmware: build instructions and protocol documentation.
• Serin firmware distribution: published controller builds.

Use examples for the CN105 component named in your configuration; other components are not interchangeable. The Matter-compatible firmware source is not published; see firmware licenses.