FaikOut WiFi Aircon Controller

Overview

The FaikOut is an open-source WiFi controller board designed to replace Daikin's cloud-dependent WiFi modules (BRP069C4x series) with a fully local, privacy-respecting alternative. Built around the ESP32-S3-PICO-1 system-in-package, it plugs directly into the S21 connector found inside compatible Daikin air conditioning units, drawing power from the air conditioner itself with no external power supply needed. The board supports Daikin units using S21, X50A, X35, and X403 protocols, automatically detecting which protocol is in use.

Control is handled entirely over the local network through MQTT, making it a natural fit for Home Assistant-based smart home setups. A built-in web interface provides basic controls for users who prefer browser-based access without needing any app or account. The device also supports BLE temperature sensors such as the BlueCoinT and Telink-based sensors, enabling remote room temperature readings to feed back into the air conditioner's control loop for more accurate climate management.

The entire project — firmware, PCB design (KiCad), and 3D-printed case files — is released under GPL-3.0, and the creator explicitly permits anyone to manufacture and sell the board with trademarks removed. The firmware is built on ESP-IDF and includes automatic over-the-air updates. With over 3,200 commits and an active community, the FaikOut represents one of the most mature open-source HVAC control projects available, backed by Andrews & Arnold Ltd, a well-established UK internet service provider.