Documentation: document nRF52832 Sparkfun board (improve MDK board a bit)

Documentation/platforms/arm/nrf52/boards/nrf52832-mdk/index.rst

@@ -2,24 +2,40 @@
 MakerDiary nRF52832-MDK
 =======================
 
-The nRF52832-MDK is a development board for the nRF52832 SoC from Nordic. It features 24 I/Os
-an on-board RGB led and a chip antenna. It also includes an embedded DAPlink debugger which
-allows to flash/debug and monitor UART from the USB port.
-
-More information about this board can be found at `MakerDiary wiki <https://wiki.makerdiary.co/nrf52832-mdk>`_.
+The `nRF52832-MDK <https://wiki.makerdiary.co/nrf52832-mdk>`_ is a development board for
+the nRF52832 SoC from Nordic. It features 24 I/Os an on-board RGB led and a chip antenna.
+It also includes an embedded DAPlink debugger which allows to flash/debug and monitor UART
+from the USB port.
 
 .. figure:: pinout.webp
    :align: center
 
    Pinout diagram
 
-.. tip:: Pins P0.19 and P0.20 correspond to UART RX/TX (from nRF52 perspective) which are connected
-   to the embedded debugger.
+Features
+========
 
-Resources
-=========
+  - nRF52832 MCU, 512K FLASH, 64K SRAM
+  - 32768 Hz crystal
+  - Embedded DAPlink debugger (debug/flash and monitor serial)
+  - Reset button
+  - Programming mode RGB LED indicator (CDC, MSD or DAP)
+  - Power indicator LED
+  - User RGB LED
+  - Inductor + capacitor for DC/DC mode
 
-The nRF52832 chip has 512K of FLASH and 64K of RAM.
+Pin Mapping
+===========
+
+===== ========== ==========
+Pin   Signal     Notes
+===== ========== ==========
+P0.24 Blue LED   Active LOW
+P0.23 Red LED    Active LOW
+P0.22 Green LED  Active LOW
+P0.20 UART TX
+P0.19 UART RX
+===== ========== ==========
 
 Configurations
 ==============

Documentation/platforms/arm/nrf52/boards/nrf52832-sparkfun/index.rst

@@ -0,0 +1,52 @@
+==========================
+Sparkfun nRF52832 Breakout
+==========================
+
+The `Sparkfun nRF52832 Breakout <https://wiki.makerdiary.co/nrf52832-mdk>`_ is basic board providing
+access to all I/O pins, a 32kHz crystal and LED. 
+
+.. figure:: board.jpg
+   :align: center
+   :width: 50%
+
+   Sparkfun nRF52832 Breakout
+
+Features
+========
+
+ - nRF52832 MCU (QFAAB0), 512K FLASH and 64 SRAM
+ - Reset and user button
+ - Power LED (blue) and user LED (red)
+ - 32768 Hz crystal
+ - NFC antenna connection pads
+ - Cortex Debug connector
+ - UART + SWD header
+
+Pin Mapping
+===========
+
+===== =========== ==========
+Pin   Signal       Notes
+===== =========== ==========
+P0.6  User Button Active LOW
+P0.7  User LED    Active LOW
+P0.26 UART TXO
+P0.27 UART RXI
+===== =========== ==========
+
+Configurations
+==============
+
+nsh
+---
+
+Basic NuttShell configuration (console enabled in UART0, at 115200 bps).
+
+Flash & Debug
+=============
+
+An external debugger is required, so the procedure to flash/debug depends on the chosen interface. Using an ST-Link V2
+you can flash using OpenOCD with::
+
+    openocd -f interface/stlink-v2.cfg -f target/nrf52.cfg -c "program nuttx/nuttx.bin 0x0000000 verify reset; shutdown"
+

NOTICE

@@ -64,3 +64,4 @@ Documentation
 
 - nRF52832-MDK board pinout image is obtained from MakerDiary GitHub repository,
   under the terms of the MIT license, Copyright (c) 2019 makerdiary.com
+- Sparkfun nRF52832 breakout board image is licensed under CC-BY 2.0 terms