# ACiQ K18W: reconstructing a mini split's UART protocol

> ACiQ K18W documents the UART protocol between a mini split's indoor board and TCL WBR1 Wi-Fi module. Captures and decoders map 115200 8N1 traffic, 0xA5 frames, CRC-16/XMODEM, acknowledgments, and appliance fields; ESPHome configurations provide passive monitoring or local control after replacing the module.

- Type: Case study
- Targets: Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-06
- Original resource: <https://github.com/codypendant/aciq-minisplit-protocol>
- Primary source: <https://github.com/codypendant/aciq-minisplit-protocol/blob/fe8a3cf59fdfc0f83d4cd65907962b2146c45188/README.md>
- Catalog page: <https://awesomerea.org/resources/aciq-minisplit-protocol-case/>
- Record JSON: <https://awesomerea.org/resources/aciq-minisplit-protocol-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/aciq-minisplit-protocol-case/index.md)

## Requirements & limits

- **Prerequisites:** An ACiQ ACIQ-K18W-W-32-HP2300 unit and ESP32 hardware for the documented ESPHome configurations.
- **Limits:** Listen-only and module-replacement control are separate electrical configurations; transmit must not be enabled while the original module remains connected.
- **License:** MIT license.

## Primary sources

1. <https://github.com/codypendant/aciq-minisplit-protocol/blob/fe8a3cf59fdfc0f83d4cd65907962b2146c45188/README.md>
2. <https://github.com/codypendant/aciq-minisplit-protocol/blob/fe8a3cf59fdfc0f83d4cd65907962b2146c45188/PROTOCOL.md>
3. <https://github.com/codypendant/aciq-minisplit-protocol/blob/fe8a3cf59fdfc0f83d4cd65907962b2146c45188/tools/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.