# ESP32-S3 GPIO Mapping

本文件按当前固件实现校对（代码 + 当前 `sdkconfig`），审计日期：2026-03-02。

## GPIO Table (Current Build)

| Board Pin | GPIO | Signal | Direction (Current Build) | Notes |
| --- | --- | --- | --- | --- |
| 1 | GND | GND | - | Ground |
| 2 | 3V3 | 3V3 | - | 3.3V Power |
| 3 | EN/RST | EN | Input | Chip enable/reset |
| 4 | IO4 | PRINT_STB5_6 | Output | Printer strobe 5/6 |
| 5 | IO5 | PRINT_STB3_4 | Output | Printer strobe 3/4 |
| 6 | IO6 | ES8311_I2C_SDA | Bidirectional | Voice codec I2C SDA |
| 7 | IO7 | ES8311_I2C_SCL | Output | Voice codec I2C SCL |
| 8 | IO15 | BATTERY_ADC | Input | Battery voltage ADC detect |
| 9 | IO16 | PRINT_STB1_2 | Output | Printer strobe 1/2 |
| 10 | IO17 | PRINT_PAPER | Input | Paper-present level is controlled by `CONFIG_TQ_PRINTER_PAPER_PRESENT_LEVEL` (current: `0`, low means paper present) |
| 11 | IO18 | NTC_ADC | Input | NTC ADC |
| 12 | IO8 | PRINT_OUTA_P | Output | Printer OUTA+ |
| 13 | IO19 | PRINT_OUTA_N | Output | Printer OUTA- |
| 14 | IO20 | ES8311_PA | Output | PA control |
| 15 | IO3 | PRINT_OUTB_P | Output | Printer OUTB+ |
| 16 | IO46 | PRINT_OUTB_N | Output | Printer OUTB- |
| 17 | IO9 | SPI_SHARED_MOSI | Output | Printer/Screen shared MOSI |
| 18 | IO10 | PRINTER_MISO | Input | Shared SPI MISO used by current screen driver config |
| 19 | IO11 | SPI_SHARED_CLK | Output | Printer/Screen shared CLK |
| 20 | IO12 | SCREEN_DC | Output | ST7789 DC |
| 21 | IO13 | SCREEN_CS (SCREEN_CS1) | Output | ST7789 CS |
| 22 | IO14 | MIC_KEY | Input | Mic key (supports ADC-mux extension path) |
| 23 | IO21 | LED_G | Output | Green LED |
| 24 | IO47 | POWER_KEY | Input | Active-low power key, long press 2s triggers lifecycle stop and power-off hold release |
| 25 | IO48 | SCREEN_BACKLIGHT | Output | Backlight active level by `CONFIG_TQ_SCREEN_BACKLIGHT_ACTIVE_HIGH` (current: `y`, high = on) |
| 26 | IO45 | PRINT_LAT | Output | Printer LAT |
| 27 | IO0 | KEY_PRINT / BOOST_CTRL | Output (current) / Input (optional) | Current build uses boost mode at boot (`CONFIG_TQ_KEY_PRINT_BOOST_ENABLE_ON_BOOT=y`), so this pin is driven as boost control |
| 28 | IO35 | N/A | - | Not available |
| 29 | IO36 | N/A | - | Not available |
| 30 | IO37 | N/A | - | Not available |
| 31 | IO38 | I2S_MCLK | Output | Voice I2S MCLK |
| 32 | IO39 | I2S_BCLK | Output | Voice I2S BCLK |
| 33 | IO40 | I2S_DI | Input | Voice I2S data in |
| 34 | IO41 | I2S_WS | Output | Voice I2S WS |
| 35 | IO42 | I2S_DO | Output | Voice I2S data out |
| 36 | TXD0 | UART0_TX | Output | Serial log/program |
| 37 | RXD0 | UART0_RX | Input | Serial log/program |
| 38 | IO2 | LED_R | Output | Red LED |
| 39 | IO1 | POWER_HOLD | Output | Must drive high at boot to keep board powered |
| 40 | GND | GND | - | Ground |
| 41 | GND | GND | - | Ground |

## Additional Runtime Pin Behavior

| Logical Signal | Config | Current Value | Behavior |
| --- | --- | --- | --- |
| SCREEN_RESET | `CONFIG_TQ_SCREEN_RESET_PIN` | `-1` | No dedicated reset pin. Runtime falls back to `CONFIG_TQ_SCREEN_BACKLIGHT_PIN` (`IO48`) as reset pin. |

## Firmware Mapping Notes (Current Implementation)

- Board pin mapping is configured through `main/Kconfig.projbuild` (`CONFIG_TQ_*`) and resolved from `sdkconfig` at build time.
- GPIO usage is config-driven. Current code path does not rely on `GPIO_NUM_xx` hardcoded pin numbers.
- `components/platform/src/platform_bootstrap.c` initializes critical GPIO on startup:
  - `POWER_HOLD` is asserted high early.
  - `LED_R` and `LED_G` default low.
  - `SCREEN_CS/DC/BACKLIGHT` are initialized with configured defaults.
  - `KEY_PRINT` is output boost control when `CONFIG_TQ_KEY_PRINT_BOOST_ENABLE_ON_BOOT=y`, otherwise input with pull-up.
  - `POWER_KEY`, `MIC_KEY`, `PRINT_PAPER` default to input with pull-up.
- Physical power-key handling uses `managed_components/espressif__button`:
  - Platform layer (`platform_power_key.c`) reports long-press events (`2s`, active-low).
  - Control-plane consumes the shutdown request and performs graceful stop, then calls `platform_power_hold_set(false)` through `system_runtime_power_off()`.
- Thermal printer runtime behavior (`components/platform/src/thermal_printer.c`):
  - `STB` lines are active-high.
  - `LAT` idles high and is pulsed low-high.
  - Shared `MOSI/CLK` are temporarily switched to GPIO bit-bang for printing.
  - Paper detect compares GPIO level against `runtime_policy_printer_paper_present_level()`.
- Display stack is:
  - `platform_display_*` (`display_st7789.c`) -> `lcd_module_*` (`display_lcd_module.c`) -> `st7789p3_*` (`display_st7789p3.c`).
  - Current implementation no longer describes panel setup in `display_st7789.c` directly.
  - LCD path includes shared-SPI recovery after printer takes over shared pins.
- Voice path (`components/platform/src/voice_audio.c`):
  - I2C defaults to `SDA=6`, `SCL=7`, with internal pull-up enabled in both I2C code paths.
  - I2S defaults to `MCLK=38`, `BCLK=39`, `WS=41`, `DOUT=42`, `DIN=40`.
  - `PA` control defaults to `IO20` and polarity can be flipped by `CONFIG_TQ_VOICE_CODEC_PA_PIN_REVERSED`.

## Condition-Driven Behavior (Important)

| Config | Current | Impact |
| --- | --- | --- |
| `CONFIG_TQ_KEY_PRINT_BOOST_ENABLE_ON_BOOT` | `y` | `KEY_PRINT/BOOST_CTRL` works as output boost-control at boot/runtime instead of key input |
| `CONFIG_TQ_KEY_PRINT_BOOST_ACTIVE_HIGH` | `y` | Boost enable level is high |
| `CONFIG_TQ_SCREEN_BACKLIGHT_ACTIVE_HIGH` | `y` | Backlight ON level is high |
| `CONFIG_TQ_SCREEN_RESET_PIN` | `-1` | Screen reset falls back to backlight pin |
| `CONFIG_TQ_SCREEN_ENABLE` | `y` | Screen driver and its GPIO paths are compiled in |
| `CONFIG_TQ_PRINTER_PAPER_PRESENT_LEVEL` | `0` | Paper detect treats GPIO low as paper present |