Documentation: add guide for pysimCoder integration with NuttX

This commit adds documentation for compiling NuttX for pysimCoder and
then running pysimCoder designed applications on NuttX. PysimCoder is
a Rapid Control Application Development Tool that can transfer block
diagrams into C code and can be used in real time control applications.

Signed-off-by: Michal Lenc <michallenc@seznam.cz>

Documentation/guides/index.rst

@@ -11,3 +11,4 @@ Guides
   drivers.rst
   tasktrace.rst
   cpp_cmake.rst
+  pysimcoder.rst

Documentation/guides/pysimcoder.rst

@@ -0,0 +1,158 @@
+.. include:: /substitutions.rst
+.. _pysimcoder:
+
+pysimCoder integration with NuttX
+=================================
+
+`PysimCoder <https://github.com/robertobucher/pysimCoder>`_ is as an open source
+Rapid Control Application Development Tool which is able to transfer block diagrams into C code.
+Combined with NuttX, it can be used in real time control application and as an alternative to
+expensive licensed programs and prototyping platforms. Example of `DC motor control application
+<https://www.youtube.com/watch?v=6HlGk3ecPNQ>`_ with PID controller and blocks for encoder,
+PWM, GPIO and sending data over TCP to real time plotter can be seen on `NuttX Channel 
+<https://www.youtube.com/channel/UC0QciIlcUnjJkL5yJJBmluw>`_.
+
+This documentation describes the steps that are needed to run application generated by pysimCoder
+on NuttX and also keeps the track of peripherals that are supported by pysimCoder for NuttX RTOS.
+
+Peripheral Support
+------------------
+
+The following list shows the peripherals and fuctionalities supported in pysimCoder for NuttX RTOS.
+
+==========  =======================
+Peripheral  Notes
+==========  =======================
+ADC
+CAN         Including SocketCAN
+DAC
+ENC
+GPIO
+PWM         Multichannel support
+UART        Serial output
+Sensors     Basic support for DHTXX
+TCP
+UDP
+==========  =======================
+
+Please note that the actual support for NuttX peripherals can be wider that what is mentioned here
+in case this documentation was not updated when new fuctionalities were added to pysimCoder.
+
+NuttX Configuration
+-------------------
+
+Several configuration options are neccessary to be set in order to succesfully compile pysimCoder
+with NuttX. The list is the following:
+
+==================================== =====================================
+``CONFIG_ARCH_RAMVECTORS=y``         ``CONFIG_NSH_FILE_APPS=y``
+``CONFIG_BOARDCTL_APP_SYMTAB=y``     ``CONFIG_NSH_LINELEN=64``
+``CONFIG_BOARDCTL_OS_SYMTAB=y``      ``CONFIG_NSH_READLINE=y``
+``CONFIG_BUILTIN=y``                 ``CONFIG_NSH_ROMFSETC=y``
+``CONFIG_CLOCK_MONOTONIC=y``         ``CONFIG_PSEUDOTERM=y``
+``CONFIG_ELF=y``                     ``CONFIG_PTHREAD_CLEANUP=y``
+``CONFIG_FS_BINFS=y``                ``CONFIG_PTHREAD_MUTEX_TYPES=y``
+``CONFIG_FS_PROCFS=y``               ``CONFIG_PTHREAD_MUTEX_TYPES=y``
+``CONFIG_FS_PROCFS_REGISTER=y``      ``CONFIG_PTHREAD_STACK_MIN=1024``
+``CONFIG_FS_ROMFS=y``                ``CONFIG_RR_INTERVAL=10``
+``CONFIG_FS_TMPFS=y``                ``CONFIG_SCHED_WAITPID=y``
+``CONFIG_IDLETHREAD_STACKSIZE=2048`` ``CONFIG_SERIAL_TERMIOS=y``
+``CONFIG_LIBC_EXECFUNCS=y``          ``CONFIG_SYMTAB_ORDEREDBYNAME=y``
+``CONFIG_LIBC_STRERROR=y``           ``CONFIG_SYSTEM_NSH=y``
+``CONFIG_MAX_TASKS=16``              ``CONFIG_SYSTEM_NSH_STACKSIZE=4096``
+``CONFIG_NSH_BUILTIN_APPS=y``        ``CONFIG_USER_ENTRYPOINT="nsh_main"``
+``CONFIG_NSH_FILEIOSIZE=512``
+==================================== =====================================
+
+In case you want to use Network and blocks like TCP or UDP, following configuration
+options are required:
+
+============================== ==================================
+``CONFIG_NET=y``               ``CONFIG_NET_ROUTE=y``
+``CONFIG_NETDB_DNSCLIENT=y``   ``CONFIG_NET_SOLINGER=y``
+``CONFIG_NETDEV_LATEINIT=y``   ``CONFIG_NET_STATISTICS=y``
+``CONFIG_NETDEV_STATISTICS=y`` ``CONFIG_NET_TCP=y``
+``CONFIG_NETINIT_DHCPC=y``     ``CONFIG_NET_TCPBACKLOG=y``
+``CONFIG_NETINIT_NOMAC=y``     ``CONFIG_NET_TCP_KEEPALIVE=y``
+``CONFIG_NETUTILS_FTPC=y``     ``CONFIG_NET_TCP_WRITE_BUFFERS=y``
+``CONFIG_NETUTILS_TELNETD=y``  ``CONFIG_NET_UDP=y``
+``CONFIG_NETUTILS_TFTPC=y``    ``CONFIG_SYSTEM_DHCPC_RENEW=y``
+``CONFIG_NET_ARP_SEND=y``      ``CONFIG_SYSTEM_NTPC=y``
+``CONFIG_NET_BROADCAST=y``     ``CONFIG_SYSTEM_PING6=y``
+``CONFIG_NET_IPv6=y``          ``CONFIG_SYSTEM_PING=y``
+``CONFIG_NET_LOOPBACK=y``      ``CONFIG_SYSTEM_TEE=y``
+``CONFIG_NET_PKT=y``
+============================== ==================================
+
+Board and application specific configuration like setting up peripherals or boot options might also be required,
+please refer to board and platform documentation for those information. Once NuttX is configured it can be build
+by simply running:
+
+  .. code-block:: console
+
+     $ make
+
+Then we need to export build NuttX which can be done by executing command
+
+  .. code-block:: console
+
+     $ make export
+
+This creates a zip file nuttx-export-xx.x.x.zip where xx.x.x is the version of NuttX. This file then have to be
+moved to pysimCoder directory pysimCoder/CodeGen/nuttx, unzip there and then renamed just to nuttx-export. Then
+enter the pysimCoder/CodeGen/nuttx/device directory and execute
+
+  .. code-block:: console
+
+     $ make
+
+This compiles pysimCoder files that controls functions of separate blocks. PysimCoder can be either installed
+on the system (please refer to the `pysimCoder manual <https://github.com/robertobucher/pysimCoder/blob/master/README.md>`_)
+or script pysim-run.sh can be used to run pysimCoder without the installation. This script can be found in pysimCoder
+root directory and is run by executing command
+
+  .. code-block:: console
+
+     $ ./pysim-run.sh
+
+Please note that PYSUPSICTRL variable has to be set/exported in order to succesfully compile NuttX application
+designed with pysimCoder.
+
+Using pysimCoder to design NuttX application
+--------------------------------------------
+
+After running pysimCoder, separate blocks can be selected from the library menu on the left hand side. The menu contains
+several libraries, NuttX specific blocks can be found in library "NuttX". It is also possible to use blocks from other
+libraries like "input", "output", "math" and so on. Several blocks can have specific parameter options and various number
+of inputs/outputs. Double left click on the block openes parameter settings while single right click on the block leads
+to number of inputs/outputs setup. The pysimCoder interface can be seen in the picture below.
+
+.. figure:: image/interface.png
+   :align: center
+   :width: 100%
+
+   pysimCoder interface: library menu can be seen on the left hand side
+
+The NuttX template Makefile nuttx.tmf has to be selected in order to generate code for NuttX target.
+This can be done in the top menu by clicking on Block settings icon which is highlighted in the red circle.
+
+.. figure:: image/menu.png
+   :align: center
+   :width: 100%
+
+   pysimCoder menu: red block settings, green generate C-code
+
+Block settings option open the following window (showed in the picture below) where you can set template Makefile and
+also Python skript with parameters for the controllers.
+
+.. figure:: image/template.png
+   :align: center
+   :width: 100%
+
+   pysimCoder Block settings menu
+
+C code can be generated by selecting Generate C-code icon (highlighted in the green cirle). Executeble files are then
+generated and can be flashed into the target. The flashing procedure can be target specific, please refer to plaftorm´s
+documentation. The generated application can be then run from NuttX command line by executing::
+
+    nsh> main