ESP32-C3 Toshiba AC Interface

Project Description

This project is a custom PCB design that integrates a Toshiba air conditioner with Home Assistant using the ESP32-C3 microcontroller and ESPHome firmware.

The board interfaces with the air conditioner using the S05B-PASK-2 connector (JST PH 5-pin) and provides bidirectional level shifting between the 5V signals from the A/C unit and the 3.3V signals required by the ESP32-C3. The design includes multiple programming and debugging options for maximum flexibility.

Key Features

• ESP32-C3-MINI-1-H4 module for WiFi connectivity
• Bidirectional level shifting with TXB0102DCT(LX) for UART communication
• AMS1117-3.3V voltage regulator for stable 3.3V power supply
• Power source selection via MK-12C02-G020 switch (USB or airco 5V)
• Boot mode (FLASH) and RESET buttons for easy programming
• Status and power indicator LEDs
• USB Type-C connector for programming 
• JTAG and UART breakout headers for debugging

Technical Details

• Power input options:
  • 5V from the air conditioner
  • 5V from USB Type-C
• Communication: UART (RX/TX) between ESP and A/C unit
• Additional debugging: JTAG interface for advanced development

Note from the Author

I'm not a professional electrical engineer, and this is a hobbyist project created to solve a specific home automation challenge. I welcome any feedback, suggestions for improvement, or reports of issues with the design. This project represents my learning journey with PCB design, so constructive input from the community is greatly appreciated!