Documentation: Add Seeed Studio XIAO ESP32S3 Board

This commit adds the documentation for Seeed Studio XIAO
ESP32S3 board. This includes examples for gpios and user leds.

Author: rcsim

Diff for: Documentation/platforms/xtensa/esp32s3/boards/esp32s3-xiao/index.rst

@@ -0,0 +1,191 @@
+=========================
+Seeed Studio XIAO ESP32S3
+=========================
+
+The `Seeed Studio XIAO ESP32S3 <https://wiki.seeedstudio.com/xiao_esp32s3_getting_started/>`_ is a general purpose board supplied by
+Seeed Studio and it is compatible with the Espressif ESP32S3 ecosystem, sharing the same MCU as ESP32-S3-DevKitC.
+
+.. figure:: xiao-esp32s3.jpg
+   :align: center
+
+Features
+========
+
+* ESP32-S3R8 Xtensa LX7 dual-core, 32-bit processor that operates at up to 240 MHz
+* On-chip 8M PSRAM & 8MB Flash
+* USB Type-C interface
+* Wireless: Complete 2.4GHz Wi-Fi subsystem;
+* BLE: Bluetooth 5.0, Bluetooth mesh
+* 1x UART, 1x I2C, 1x I2S, 1x SPI, 11x GPIOs (PWM), 9x ADC
+* 1 user LED, 1 power LED
+* 1 RESET button, 1 BOOT button
+
+NSH Console
+===========
+
+The NuttShell (NSH) console is available over USB using the CDC/ACM
+serial interface. To access the console, connect via a terminal emulator
+at 115200 baud, 8 data bits, no parity, and 1 stop bit (115200-8N1).
+
+User LED
+========
+
+The USER LED, a yellow LED located on the XIAO ESP32S3 board, is
+connected to GPIO21 as indicated in the board's schematic. This LED
+can be controlled through NuttX by configuring GPIO21 as an output
+and toggling its state.
+
+Buttons
+=======
+
+The RESET and BOOT buttons can be used to enter "Bootloader" mode by
+press and hold the BOOT key while powering up and then press the RESET key once.
+
+Pin Mapping
+===========
+Pads numbered anticlockwise from USB connector.
+
+===== ========== ==========
+Pad   Signal     Notes
+===== ========== ==========
+0     GPIO01     D0/A0
+1     GPIO02     D1/A1
+2     GPIO03     D2/A2
+3     GPIO04     D3/A3
+4     GPIO05     D4/SDA
+5     GPIO06     D5/SCL
+6     GPIO43     D6/Default TX for UART0 serial console
+7     GPIO44     D7/Default RX for UART0 serial console
+8     GPIO07     D8/SCK
+9     GPIO08     D9/MISO
+10    GPIO09     D10/MOSI
+11    3V3        Power output to peripherals
+12    Ground
+13    VIN        +5V Supply to board
+===== ========== ==========
+
+Power Supply
+============
+The working voltage of the MCU is 3.3V. Voltage input connected to
+general I/O pins may cause chip damage if it’s higher than 3.3V.
+
+Installation
+============
+
+1. Configure and build NuttX:
+
+.. code-block:: console
+
+  $ git clone https://github.com/apache/nuttx.git nuttx
+  $ git clone https://github.com/apache/nuttx-apps.git apps
+  $ cd nuttx
+  $ make distclean
+  $ ./tools/configure.sh xiao-esp32s3:usbnsh
+  $ make V=1
+
+2. Connect the Seeed Studio XIAO ESP32S3, and enter "Bootloader" mode,
+then, flash the ``nuttx.hex`` file using ``esptool``:
+(https://docs.espressif.com/projects/esptool/en/latest/esp32/)
+
+Example command:
+
+.. code-block:: bash
+
+    make flash ESPTOOL_PORT=/dev/ttyACM0 ESPTOOL_BINDIR=./
+
+
+Configurations
+==============
+
+usbnsh
+------
+Basic NuttShell configuration using CDC/ACM serial (console enabled in USB Port,
+at 115200 bps).
+
+.. code-block:: console
+
+  NuttShell (NSH) NuttX-12.8.0
+  nsh> uname -a
+  NuttX 12.8.0 2c845426da-dirty Apr  6 2025 22:53:57 xtensa esp32s3-xiao
+
+
+combo
+-----
+This configuration enabled NuttShell via USB and enabled led and gpio examples:
+
+Testing leds:
+
+.. code-block:: console
+
+  nsh> leds
+  leds_main: Starting the led_daemon
+  leds_main: led_daemon started
+
+  led_daemon (pid# 10): Running
+  led_daemon: Opening /dev/userleds
+  led_daemon: Supported LEDs 0x01
+  led_daemon: LED set 0x01
+  nsh> led_daemon: LED set 0x00
+  led_daemon: LED set 0x01
+  led_daemon: LED set 0x00
+  led_daemon: LED set 0x01
+  led_daemon: LED set 0x00
+
+Testing gpios:
+
+========   ======   ==========
+PIN/GPIO    Mode      Device
+========   ======   ==========
+D1/GPIO2   Output   /dev/gpio0
+D0/GPIO1   Input    /dev/gpio1
+D2/GPIO3   Input    /dev/gpio2
+========   ======   ==========
+
+.. code-block:: console
+
+  nsh> ls /dev
+  /dev:
+   console
+   gpio0
+   gpio1
+   gpio2
+   null
+   ttyACM0
+   ttyS0
+   userleds
+   zero
+  nsh> gpio -o 1 /dev/gpio0
+  Driver: /dev/gpio0
+    Output pin:    Value=0
+    Writing:       Value=1
+    Verify:        Value=1
+  nsh> gpio -o 0 /dev/gpio0
+    Driver: /dev/gpio0
+    Output pin:    Value=1
+    Writing:       Value=0
+    Verify:        Value=0
+  nsh> gpio /dev/gpio1
+  Driver: /dev/gpio1
+    Input pin:     Value=0
+  nsh> gpio /dev/gpio1
+  Driver: /dev/gpio1
+    Input pin:     Value=1
+  nsh> gpio /dev/gpio1
+  Driver: /dev/gpio1
+    Input pin:     Value=0
+  nsh> gpio -w 1 /dev/gpio2
+  Driver: /dev/gpio2
+    Interrupt pin: Value=0
+    Verify:        Value=1
+  nsh> gpio -w 1 /dev/gpio2
+  Driver: /dev/gpio2
+    Interrupt pin: Value=0
+    Verify:        Value=1
+
+
+
+
+
+
+
+