I Made a Non-Wi-Fi Mitsubishi AC Smart with an ESP32

In a recent project, a developer successfully integrated a legacy, non-Wi-Fi Mitsubishi air conditioning unit into a Home Assistant smart home ecosystem. By utilizing an ESP32 microcontroller, the author bypassed the lack of native connectivity in older hardware. The project involved reverse-engineering the infrared communication protocol used by the AC unit's remote control. By capturing and emulating these signals, the developer created a bridge that allows for remote control, scheduling, and automation of the climate system through Home Assistant. This DIY approach demonstrates how inexpensive hardware components can extend the lifespan of older appliances by providing them with modern smart features. The article provides a detailed technical breakdown of the wiring, the ESPHome configuration, and the logic required to map specific AC functions to digital commands, offering a practical guide for users looking to modernize their existing home infrastructure without replacing functional but 'dumb' hardware.