# 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