> ## Documentation Index
> Fetch the complete documentation index at: https://docs.protonverse.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Proton AI Core GPIO and Peripheral Pinout Reference

> GPIO pinout reference for Proton AI Core. Maps each physical header pin to ESP32-S3 function, including UART, SPI, I2C, and camera interface pins.

Proton AI Core exposes the ESP32-S3's GPIO bank through a set of through-hole headers along both edges of the board. The pins give you access to all major peripherals — UART, I2C, SPI, ADC, and PWM — while a dedicated FPC connector handles the camera interface separately. Before wiring up external hardware, review the reserved pins below and verify any assignments against the board schematic.

<Warning>
  GPIO voltage is 3.3V. Do not connect 5V signals directly to GPIO pins — this may damage the ESP32-S3.
</Warning>

## Reserved Pins

Certain GPIO pins are committed to on-board peripherals and should not be used for general-purpose I/O. Connecting external hardware to these pins can interfere with camera operation, USB communication, or internal flash access.

| Function               | Pin(s)          |
| ---------------------- | --------------- |
| Camera interface (DVP) | To be confirmed |
| USB D+ / D−            | GPIO19, GPIO20  |
| Internal Flash / PSRAM | To be confirmed |
| Boot / strapping pins  | GPIO0, GPIO46   |

<Note>
  The complete pinout diagram PDF — including exact physical pin positions — is available on the [Downloads](/resources/downloads) page.
</Note>

## Common Pin Functions

The table below lists the default peripheral assignments for UART, I2C, and SPI on the ESP32-S3. These reflect standard Espressif defaults; always verify them against your specific board schematic before use, as the Proton AI Core firmware may remap certain pins.

| Peripheral | Signal | GPIO   | Notes                                  |
| ---------- | ------ | ------ | -------------------------------------- |
| UART0      | TX     | GPIO43 | Default console / programming port     |
| UART0      | RX     | GPIO44 | Default console / programming port     |
| I2C        | SDA    | GPIO8  | Verify with your board's schematic     |
| I2C        | SCL    | GPIO9  | Verify with your board's schematic     |
| SPI        | MOSI   | GPIO11 | Default SPI bus; verify with schematic |
| SPI        | MISO   | GPIO13 | Default SPI bus; verify with schematic |
| SPI        | SCK    | GPIO12 | Default SPI bus; verify with schematic |
| SPI        | CS     | GPIO10 | Default SPI bus; verify with schematic |

## Camera Interface Pins

The camera module connects through a dedicated FPC (Flexible Printed Circuit) connector rather than the main GPIO headers. Internally, it uses the ESP32-S3's parallel DVP (Digital Video Port) interface, which requires several data lines, a pixel clock, synchronisation signals, and an I2C bus for sensor configuration.

Exact pin assignments for the DVP interface are **To be confirmed** pending finalisation of the hardware design. Refer to the [Cameras](/hardware/cameras) page for a full breakdown of supported modules and connection steps, and watch the [Downloads](/resources/downloads) page for the released schematic.

## Power Pins

The following power pins are available on the GPIO headers for supplying or referencing voltage in your circuits.

| Pin Label | Voltage | Description                              |
| --------- | ------- | ---------------------------------------- |
| 3V3       | 3.3V    | Regulated output from the on-board LDO   |
| 5V (VBUS) | 5V      | Passed directly from the USB-C VBUS rail |
| GND       | 0V      | Common ground reference                  |

<Info>
  The complete pinout diagram PDF is available on the [Downloads](/resources/downloads) page.
</Info>