# ha-c14: reconstructing the C14 ventilator bus protocol

> ha-c14 documents the C14 RS-485 bus between a COMPIT AERO 3B ventilator and Nano Color CTP room panel and implements an ESPHome bridge for ESP32. Its protocol notes describe 30-byte frames, master cycles and device roles; the YAML package parses frames and exposes controls and sensors to Home Assistant.

- Type: Case study
- Targets: Protocol
- Category: Independent reconstruction cases
- Relationship: Independent reconstruction project
- Sources reviewed: 2026-11-07
- Added to the catalog: 2026-11-09
- Original resource: <https://github.com/Pioszym/ha-c14>
- Primary source: <https://github.com/Pioszym/ha-c14/blob/3746e031414c899eb939ffdc5395b4592f613a62/PROTOCOL.md>
- Catalog page: <https://awesomerea.org/resources/ha-c14-case/>
- Record JSON: <https://awesomerea.org/resources/ha-c14-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/ha-c14-case/index.md)

## Requirements & limits

- **Prerequisites:** An ESP32-compatible board and a 3.3 V RS-485 interface connected to the C14 bus are required.
- **Prerequisites:** ESPHome and Home Assistant are used for the provided integration.
- **Limits:** Protocol reverse engineering is ongoing and some fields remain unresolved.
- **License:** Documentation is CC BY-SA 4.0; firmware code is MIT.

## Primary sources

1. <https://github.com/Pioszym/ha-c14/blob/3746e031414c899eb939ffdc5395b4592f613a62/PROTOCOL.md>
2. <https://github.com/Pioszym/ha-c14/blob/3746e031414c899eb939ffdc5395b4592f613a62/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.