Updated documentation

Author: Fescron

software/EFM32HG-Embedded2-project/inc/documentation.h

@@ -1,7 +1,7 @@
 /***************************************************************************//**
  * @file documentation.h
  * @brief This file contains useful documentation about the project.
- * @version 3.0
+ * @version 3.1
  * @author Brecht Van Eeckhoudt
  *
  * ******************************************************************************
@@ -271,17 +271,25 @@
  *
  *   The `volatile` type indicates to the compiler that the data is not normal memory,
  *   and could change at unexpected times. Hardware registers are often volatile,
- *   and so are variables which get changed in interrupts.
+ *   and so are variables which get changed in interrupts.@n
+ *   Volatile variables are stored in *RAM*.
  *
- *   @subsection Extern
+ *   @subsection Static
  *
- *   Declare the global variables in headers (and use the `extern` keyword there)
- *   and actually define them in the appropriate source file.
+ *   @subsubsection VARIABLE Static variable
  *
- *   @subsection Static
+ *   During compile time (this is why we can't use variable length array's) memory
+ *   gets reserved for this variable. The data itself gets put in the *data* segment
+ *   of the memory (regular variables are put in the *stack* segment).@n
+ *   It's best to keep the use of `static` variables to a minimum. One should ask
+ *   himself the question if it's necessary to keep the variable constantly in the
+ *   memory. If the answer is yes, a `static` variable is acceptable.@n
+ *   A **static variable inside a function** keeps its value between invocations.
+ *
+ *   @subsubsection FUNCTION Static global function
  *
- *   - **Static variable inside a function:** The variable keeps its value between invocations.
- *   - **Static global variable or function:** The variable or function is only "seen" in the file it's declared in.
+ *   The function is only "seen" in the file it's declared in. This means `static`
+ *   can be used for methods the same way `private` is used for certain methods in C++.
  *
  * ******************************************************************************
  *

software/EFM32HG-Embedded2-project/lora/util_string.c

@@ -38,18 +38,23 @@ bool HexToString(uint8_t * bin, uint8_t binsz, char **result ){
 	char hex_str[] = "0123456789abcdef";
 	uint8_t i;
 
-	// Hex to string/char aray: one value becomes two chars (*2)
+	// ALLOCATE MEMORY
+	// Hex to string/char array: one value becomes two chars (*2)
 	//   +1 because of NULL termination
+	// "*result =" ~ Value at memory location gets changed
 	if (!(*result = (char *)malloc(binsz * 2 + 1))){
-		return (false);
+		return (false); // Returned when NULL
 	}
 
-	(*result)[binsz * 2] = 0;
+	// Add NULL termination
+	(*result)[binsz * 2] = 0; // Last memory location, "0" ~ '\0'
 
+	// CHECK MEMORY
 	if (!binsz){
-		return (false);
+		return (false); // Returned when NULL
 	}
 
+	// FILL WITH DATA
 	for (i = 0; i < binsz; i++){
 	  (*result)[i * 2 + 0] = hex_str[(bin[i] >> 4) & 0x0F];
 	  (*result)[i * 2 + 1] = hex_str[(bin[i]     ) & 0x0F];