# ESP32-S3 Pin Mapping - PoE Presence Sensor

## GPIO Assignments

| GPIO | Function | Peripheral | Direction | Notes |
|------|----------|-----------|-----------|-------|
| GPIO0 | BOOT button | - | Input | Pull-up, hold low for bootloader |
| GPIO1 | Camera D0 | OV5640 DVP | Input | Camera data bus |
| GPIO2 | Camera D1 | OV5640 DVP | Input | Camera data bus |
| GPIO3 | I2C SDA | SHT41 + BH1750 | Bidir | 4.7K pull-up |
| GPIO4 | I2C SCL | SHT41 + BH1750 | Bidir | 4.7K pull-up |
| GPIO5 | Camera D2 | OV5640 DVP | Input | Camera data bus |
| GPIO6 | Camera D3 | OV5640 DVP | Input | Camera data bus |
| GPIO7 | Camera D4 | OV5640 DVP | Input | Camera data bus |
| GPIO8 | Camera D5 | OV5640 DVP | Input | Camera data bus |
| GPIO9 | Camera D6 | OV5640 DVP | Input | Camera data bus |
| GPIO10 | Camera D7 | OV5640 DVP | Input | Camera data bus |
| GPIO11 | Camera XCLK | OV5640 | Output | 20MHz LEDC |
| GPIO12 | Camera PCLK | OV5640 | Input | Pixel clock |
| GPIO13 | Camera VSYNC | OV5640 | Input | Vertical sync |
| GPIO14 | Camera HREF | OV5640 | Input | Horizontal ref |
| GPIO15 | Camera SIOD | OV5640 SCCB | Bidir | Camera I2C data |
| GPIO16 | Camera SIOC | OV5640 SCCB | Output | Camera I2C clock |
| GPIO17 | mmWave UART TX | LD2410C RX | Output | 256000 baud |
| GPIO18 | mmWave UART RX | LD2410C TX | Input | 256000 baud |
| GPIO19 | Free | - | - | (was USB D-) |
| GPIO20 | Free | - | - | (was USB D+) |
| GPIO21 | Camera PWDN | OV5640 | Output | Power down |
| GPIO33 | W5500 SPI MISO | Ethernet | Input | SPI data in |
| GPIO34 | W5500 SPI MOSI | Ethernet | Output | SPI data out |
| GPIO35 | W5500 SPI SCK | Ethernet | Output | SPI clock (25MHz max) |
| GPIO36 | W5500 SPI CS | Ethernet | Output | SPI chip select |
| GPIO37 | W5500 INT | Ethernet | Input | Interrupt (active low) |
| GPIO38 | PIR output | AM312 | Input | Motion detect |
| GPIO39 | mmWave OUT | LD2410C | Input | Presence output |
| GPIO40 | Status LED | Blue LED | Output | Via 1K resistor |
| GPIO41 | Camera RESET | OV5640 | Output | Active low |
| GPIO42 | W5500 RST | Ethernet | Output | Active low |

## SPI Bus (GPIO33-36) - W5500 Ethernet
| Signal | GPIO | W5500 Pin |
|--------|------|-----------|
| MISO | GPIO33 | SO |
| MOSI | GPIO34 | SI |
| SCK | GPIO35 | SCLK |
| CS | GPIO36 | SCSn |
| INT | GPIO37 | INTn |
| RST | GPIO42 | RSTn |

## I2C Bus (GPIO3/GPIO4) - Sensors
| Device | Address | Function |
|--------|---------|----------|
| SHT41 | 0x44 | Temperature + Humidity |
| BH1750 | 0x23 | Ambient Light |

## UART1 (GPIO17/GPIO18) - Radar
| Device | Baud | Function |
|--------|------|----------|
| LD2410C | 256000 | mmWave presence |