ESP_Midea/Midea_ESP/README.md

Midea AC Controller PCB Design

Custom PCB design for controlling Midea/Inventor AC units using ESP32 with BLE beacon capabilities.

Project Files

• Midea_ESP.kicad_pro - KiCad project file
• Midea_ESP.kicad_sch - Schematic file
• Midea_ESP.kicad_pcb - PCB layout file
• Midea_ESP.kicad_prl - Project local settings

Custom Library

• libs/Midea_AC_Controller.kicad_sym - Custom symbol library containing:
  • ESP32-WROOM-32E
  • TXB0104PWR (Level shifter)
  • AMS1117-3.3 (Voltage regulator)
  • CP2102N (USB-to-Serial - not used, kept for reference)

Documentation

• SCHEMATIC_COMPONENT_LIST.md - Complete component list with pin-by-pin connections and schematic structure
• QUICK_START_SCHEMATIC.md - Step-by-step guide for building the schematic in KiCad
• PROGRAMMING_HEADER.md - Programming header pinout and connection guide
• COMPONENT_SIZES.md - Recommended package sizes for all components (capacitors, resistors, LEDs, etc.)
• AC_CONNECTION.md - AC connector pinout and connection guide

Getting Started

1. Open the project in KiCad: kicad Midea_ESP.kicad_pro
2. Follow QUICK_START_SCHEMATIC.md to build the schematic
3. Refer to SCHEMATIC_COMPONENT_LIST.md for detailed component information
4. Use PROGRAMMING_HEADER.md when connecting a USB-to-Serial adapter for flashing

Design Features

• ESP32-WROOM-32E microcontroller
• 5V to 3.3V voltage regulation (AMS1117-3.3)
• 3.3V ↔ 5V level shifter (TXB0104PWR) for AC communication
• Programming header for external USB-to-Serial adapter
• Reset and boot buttons
• Status LEDs
• JST-XH connector (J1) - Provides power input and AC communication

Power Supply

• Power Input: J1 Pin 1 (+5V) - Powers the entire PCB
• Voltage Regulator: AMS1117-3.3 converts 5V to 3.3V for ESP32
• Ground: J1 Pin 4 (GND)

Cost Optimization

• Uses programming header instead of onboard USB-to-Serial chip (saves ~$2.50 per board)
• Minimal component count while maintaining functionality