Creating-an-application.md

+Creating an application       {#creating-an-application}
+=======================
+\author Zakaria Kasmi
+
+[TOC]
+
+An application can be created for full-fledged or resource-limited devices.
+
+Creating an application for full-fledged devices       {#creating-an-application-full-fledge}
+================================================
+We recommend to use the [Eclipse IDE] (https://www.eclipse.org/) for C/C++ Developers for creating
+own application. The simplest way to write your own application, is to put your *.c and *.h files under the 
+`src` directory. Another way is to create a directory containing the multiple C file(s) with your
+source code. The header files can be imported in the Eclipse IDE by opening Project->Properties and 
+selecting  ''C/C++ General->Paths and Symbols->Languages->GNU C'' from the Selection Wizard. Click the ''Add..'' 
+button to browse to the header-directory and the select the ''Apply'' and ''OK'' buttons. The users can be 
+oriented to the main.c and the examples under the src-directory. 
+
+  
+Creating an application for resource-limited devices   {#creating-an-application-res-lim}
+====================================================
+To create your own application for a resource limited device you need to create a directory
+containing one or multiple C file(s) with your source code and a Makefile. An example Makefile is
+available in the `src` folder of the [RcdMathLib repository]
+(https://git.imp.fu-berlin.de/zkasmi/my_lib_full_fledged_devices/tree/master/RcdMathLib_app).
+
+The main function                                          {#the-main-function}
+=================
+RIOT starts two threads the idle and main threads after the board is initialized.
+The idle thread has the lowest priority while the main thread has a priority that
+is in the middle between the lowest and the highest available priorities. The main 
+thread is the first that runs and calls the `main()` function.
+This function needs to be defined in the source code of each application
+(typically located in the `main.c` file). 
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.c}
+#include <stdio.h>
+
+#include "matrix_test.h"
+#include "vector_test.h"
+
+int main(void)
+{
+    puts("RcdMathLib Application!");
+    // Test the basic operations module;
+    matrix_test();
+    vector_test();
+    
+    return EXIT_SUCCESS;
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The above C code shows an application testing the basic operations sub-modules. 
+This application run operations of the vector and matrix sub-modules. 
+
+The application's Makefile                         {#the-applications-makefile}
+==========================
+The minimal Makefile                                    {#the-minimal-makefile}
+--------------------
+At minimum the Makefile of an application (see @ref getting-started) needs to
+define the following macros:
+ * `APPLICATION`: contains the name of your application
+ * `RIOTBASE`: specifies the path to your copy of the RIOT repository (note,
+   the `$(CURDIR)` macro can be used to give a relative path)
+ * `RCDMATHLIB`: specifies the path to the copy of the RcdMathLib repository (note,
+   the `$(CURDIR)` macro can be used to give a relative path)
+ * `USEMODULE`: specifies the module of the RcdMathLib that you may want to use
+
+The `BOARD` macro is also required and recommended to be set to `native` by
+default, but is recommended to be overridable with the `?=` operator.
+Additionally, it is required to include the `Makefile.include` from the RcdMathLib and from the
+`RIOTBASE`.
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~ {.mk}
+# Set the name of your application:
+APPLICATION = foobar
+
+# If no BOARD is found in the environment, use this default:
+BOARD ?= native
+
+# This has to be the absolute path to the RcdMathLib base directory:
+RCDMATHLIB ?= $(CURDIR)/../RcdMathLib
+
+# This has to be the absolute path to the RIOT base directory:
+RIOTBASE ?= $(CURDIR)/../../RIOT
+
+
+include $(RCDMATHLIB)/Makefile.include
+include $(RIOTBASE)/Makefile.include
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Including modules                                          {#including-modules}
+-----------------
+The modules of the RcdMathLib as well as of the RcdMathLib can be included.
+In order to use additional modules, such as a particular driver or a system library, the modules' 
+names must be appended to the USEMODULE variable. For example, to build an application using the SHT11 
+temperature sensor and UDP/IPv6 functionalities, the Makefile needs to contain the following lines: 
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~ {.mk}
+USEMODULE += sht11
+USEMODULE += gnrc_ipv6_default
+USEMODULE += gnrc_udp
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For example, to create an application using the matrix decompositions, the pseudo-inverse, and solving
+linear equations sub-modules, the Makefile must comprise the following lines: 
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~ {.mk}
+USEMODULE += matrix_decompositions
+USEMODULE += pseudo_inverse
+USEMODULE += utilities
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+