# TCL AC Original Module ESPHome: reconstructing WL6U air-conditioner control

> TCL AC Original Module ESPHome reconstructs local control of a TCL air conditioner on its original WL6U Wi-Fi module. The author traced command building and status decoding in a stock RTL8720CF firmware dump, compared selected functions with replacement codecs, and implemented ESPHome controls and readings over the module's UART link.

- Type: Case study
- Targets: Firmware · Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-08
- Original resource: <https://github.com/kralonur/tcl-ac-original-module-esphome>
- Primary source: <https://github.com/kralonur/tcl-ac-original-module-esphome/blob/a18fbab784b56f5f93766c944c1814ba1d6e82bf/docs/REVERSE_ENGINEERING.md>
- Catalog page: <https://awesomerea.org/resources/tcl-ac-original-module-esphome-case/>
- Record JSON: <https://awesomerea.org/resources/tcl-ac-original-module-esphome-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/tcl-ac-original-module-esphome-case/index.md)

## Requirements & limits

- **Prerequisites:** An original WL6U_V4.0 module with RTL8720CF and 2 MiB flash; first installation needs a 3.3 V USB–UART adapter, 5 V supply and Linux computer.
- **Prerequisites:** Back up the original firmware before writing; the module must be disconnected from AC mains during programming.
- **Testing evidence:** The author tested one TAC-12CHSD; other models and full stock restoration remain untested.
- **License:** Apache-2.0 and MIT license files are included.

## Primary sources

1. <https://github.com/kralonur/tcl-ac-original-module-esphome/blob/a18fbab784b56f5f93766c944c1814ba1d6e82bf/docs/REVERSE_ENGINEERING.md>
2. <https://github.com/kralonur/tcl-ac-original-module-esphome/blob/a18fbab784b56f5f93766c944c1814ba1d6e82bf/README.md>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.