# ESP32-S3 GPIO Mapping

本文件记录当前板级 GPIO 分配，来源于硬件对接表（2026-02-26）。

## GPIO Table

| Board Pin | GPIO | Signal | Direction | 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 detect |
| 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 | Printer MISO |
| 19 | IO11 | SPI_SHARED_CLK | Output | Printer/Screen shared CLK |
| 20 | IO12 | SCREEN_DC | Output | ST7789 DC |
| 21 | IO13 | SCREEN_CS1 | Output | ST7789 CS |
| 22 | IO14 | MIC_KEY | Input | Mic key (can ADC-mux 2 keys if needed) |
| 23 | IO21 | LED_G | Output | Green LED |
| 24 | IO47 | POWER_KEY | Input | Hold low for 2s to request power-off logic |
| 25 | IO48 | SCREEN_BACKLIGHT | Output | High level turns backlight on |
| 26 | IO45 | PRINT_LAT | Output | Printer LAT |
| 27 | IO0 | KEY_PRINT / BOOST_CTRL | Input/Output | Print confirm key or 7.2V 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 |

## Firmware Mapping Notes

- `main/Kconfig.projbuild` contains board pin configs prefixed with `TQ_*`.
- `components/platform/src/platform_bootstrap.c` initializes critical GPIO on startup:
  - `POWER_HOLD` asserted high early.
  - `SCREEN_DC/SCREEN_CS/SCREEN_BACKLIGHT` default states.
  - `KEY_PRINT` defaults to boost-enable output mode (`CONFIG_TQ_KEY_PRINT_BOOST_ENABLE_ON_BOOT=y`).
  - key/sensor inputs (`POWER_KEY`, `MIC_KEY`, `PRINT_PAPER`, ADC inputs) default directions.
- `components/platform/src/display_st7789.c` provides ST7789 driver integration:
  - SPI bus (`MOSI=IO9`, `CLK=IO11`) + `esp_lcd_new_panel_st7789`.
  - Optional boot test pattern via `CONFIG_TQ_SCREEN_TEST_PATTERN_ON_BOOT`.
- Voice codec and I2S pin defaults are aligned to this table:
  - I2C: `SDA=6`, `SCL=7`
  - I2S: `MCLK=38`, `BCLK=39`, `WS=41`, `DIN=40`, `DOUT=42`
  - PA: `IO20`