# Fisher & Paykel RF505BRNUX1: decoding refrigerator board traffic

> The Fisher & Paykel RF505BRNUX1 bridge decodes two 9600-baud serial links on the refrigerator's main board and exposes door, setting, compressor, defrost, and temperature states to Home Assistant. Its documentation specifies frame layout, CRC-16/MODBUS, addresses, and byte maps; an ESPHome configuration reads the links without transmitting.

- Type: Case study
- Targets: 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/nickthelomas/esphome-fisher-paykel-fridge>
- Primary source: <https://github.com/nickthelomas/esphome-fisher-paykel-fridge/blob/0bd8abc2b6b4ff6dcead77b0cfeea65b5327e6f8/README.md>
- Catalog page: <https://awesomerea.org/resources/fisher-paykel-fridge-bus-case/>
- Record JSON: <https://awesomerea.org/resources/fisher-paykel-fridge-bus-case/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/fisher-paykel-fridge-bus-case/index.md)

## Requirements & limits

- **Prerequisites:** A Fisher & Paykel RF505BRNUX1 refrigerator and Seeed XIAO ESP32-C3 are needed for the documented setup.
- **Prerequisites:** The ESPHome configuration targets version 2026.10 and requires Wi-Fi secrets and an isolated 5 V supply.
- **Limits:** Other F&P or Haier boards may differ; the author advises checking their byte map with a logic analyser.
- **License:** MIT.

## Primary sources

1. <https://github.com/nickthelomas/esphome-fisher-paykel-fridge/blob/0bd8abc2b6b4ff6dcead77b0cfeea65b5327e6f8/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.