Description refined. Added Basic-examples - but work on hold.

docs/d2d/basic-example.rst

@@ -0,0 +1,65 @@
+*******************
+D2D - Basic example
+*******************
+
+Library initialization
+----------------------
+This article tackles the bacis example of how to use **D2D** library.
+The use case used in the example is very simple and can be a starter
+point for building an **Application Layer** and communication between
+devices.
+
+.. note::
+
+    The code below shows how to use **D2D** libary with **ST Microelectronics**
+    **STM32** microcontrollers with support of **LL** and **HAL** drivers.
+
+The basic setup of the library requires initialization of the **D2D** library
+itself and its dependencies as well.
+
+.. code-block:: C++
+    :linenos:
+
+    /* Includes ------------------------------------------------------------------*/
+    // Include Timer module (D2D dependency)
+    #include "timer.h"
+    // Include PRNG module (D2D dependency)
+    #include "prng.h"
+    // Include D2D library
+    #include "d2d_tl.h"
+
+    ...
+
+
+
+    ...
+
+    int main(void)
+    {
+        // Initilize D2D library and its dependencies
+        {
+            // Number of send attempts for D2D library
+            uint8_t sendAttemptsMax = 6;
+
+            // Initialize Timer module
+            timer_init();
+
+            // Initialize Pseugo Random Number Generator module
+            prng_init();
+
+            // Initialize D2D library
+            d2d_tl_init(sendAttemptsMax);
+            d2d_tl_register_cbs(&tlCbs);
+        }
+    }
+
+
+
+What next
+---------
+..
+
+
+**Footnote**
+
+**kaeraz**, 2019/02

docs/d2d/hw-setup.rst

@@ -14,6 +14,11 @@ with the use of an **UART** microcontroller interface. In general the library
     - Medium interface error detection
     - Frame CRC calculation and verification
 
+.. note::
+
+    Examplary code and hardware is based on UART microcontroller's
+    peripheral.
+
 Hardware circuit
 ----------------
 Example solution of **L1** uses standard **UART interface** for sending signals

docs/d2d/sw-setup.rst

@@ -7,10 +7,15 @@ Introduction
 This chapter describes how to seput the **D2D** library. In general,
 correct setup requires few actions:
 
-    - **Link Layer** setup to support used microcontroller
+    - setup of **Link Layer** to support used microcontroller
     - **Pseudo Random Number Generator** setup
     - **Timer** module setup
 
+.. note::
+
+    The **D2D** library depends on two additional modules:
+    **Timer** module and **PSNG** module.
+
 Layer 2: Link Layer overview
 ----------------------------
 The **Link Layer** also called **Data Link Layer** is responsible for
@@ -209,7 +214,7 @@ in the **D2D** repository. The quick-and-dirty implementation for
 **ST Microelectronis** **STM32** microcontrollers is shown below.
 
 .. code-block:: C++
-    :lineos:
+    :linenos:
 
     void prng_init_bit_generator(void)
     {
@@ -273,10 +278,31 @@ The next section describes the **Timer** modules.
 
 Dependencies: Timer setup
 -------------------------
+The **D2D** library depends on **Timer** module, which provides
+a time counting facility. When **Timer** object is created
+it registers user callback method that is called after time
+expiration. There is little to setup in case of **Timer** module.
+One has to set a maximum number of **Timer** objects in the
+``timer_config.h`` file.
+
+.. code-block:: C++
+    :linenos:
+
+    /**
+     * @brief Defines number of Timers used in the application.
+     * 
+     */
+    #define TIMER_NO_TIMERS  (2) // Value of 2 is a minimum number of Timers
+                                 // for D2D library.
+
+The **D2D** library requires at least two **Timer** objects for
+proper operation.
 
 What next
 ---------
-
+After having an overview how to setup a **D2D** library, there
+is a time to dig into an example code. The next article covers
+this topic.
 
 
 **Footnote**