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Coding Standard

Author: T.Meerstetter

To ensure a common coding style in the software some rules are defined.

! This Guidelines are still under construction !

#Overview

Acronym	Description
l	l ong - 32 bit variable
s	s hort - 16 bit variable
c	c har - 8 bit variable
u	u nsigned - e.g. ul = unsigned long
e	e numeration
p	p ointer - e.g. pl = pointer to long
v	v oid - functions with no return type
prv	pr i v ate - File intern functions
os	o perating s ystem - RTX Thread functions
######Table: Prefix acronym list

#Naming Conventions

##Variables ####Prefix Variables which are visible outside of a function follow these rules:

• Variables of type uint32_t are prefixed ul, where the 'u' denotes 'unsigned' and the 'l' denotes 'long'.

• Variables of type uint16_t are prefixed us, where the 'u' denotes 'unsigned' and the 's' denotes 'short'.

• Variables of type uint8_t are prefixed uc, where the 'u' denotes 'unsigned' and the 'c' denotes 'char'.

• Variables of non stdint types are prefixed x.

• Unsigned variables of non stdint types have an additional prefix u.

• Enumerated variables are prefixed e

• Pointers have an additional prefixed p, for example a pointer to a uint16_t will have prefix pus.

• Function intern variables don’t need these prefixes, but they should have meaningful names.

####Case Sensitivity

• Variables start with a lowercase letter.
• Every new word in the name starts with an uppercase letter

Example: uint32_t ulTestVariable or with no prefix (function intern variable): uint32_t testVariable

##Functions ####Prefix

• File scope static (private) functions are prefixed with prv.
• API functions are prefixed with their return type, as per the convention defined for variables, with the addition of the prefix v for void.
• Keil RTX functions (thead initialisation) are prefixed with os for operating system

####Case Sensitivity

• All functions start with the lowercase prefix

• Every new word in the name starts with an uppercase letter , just like variables

  Example:

  void prvFunctionName(uint32_t ulInput)
  {
      ...
  }

  ######Code: Example of a function

##Defines

• Defines are all written in **upper case ** letters and are separated with an underscore

• Global used defines are located in the header files.

• Only file intern used defines are located in the source file.

  Example:

  #define DEFINE_NAME "Name"

  ######Code: Example of a define

##Macros

• Macros are prefixed with a lower case indicator of the macros origin file.

• After the prefix all letters are upper case and are separated with an underscore

  Example:

  #define ledGPIO_HIGH(a,b) 	a->BSRRL = b

  ######Code: Macro to set a LED GPIO, located in the led.c/.h file.

#Style Guide

##Headers

Every souce- / headerfile or function has a Doxygen conform comment header with a short description and some other information. The Header files used in this software are located in extern Gists (see section below).

Example:

/***********************************************************************/
/* Function:  prvFunctionName                                          */
/***********************************************************************/
/*! \brief Short description of the function
*
* Function : More detailed description of the function
*
* \param[in] ulInput  Comment for parameter1
*
* \return None
*
* \author Name
*
* \version 0.0.1
*
* \date dd.mm.jjjj Function created
*
************************************************************************/
void prvFunctionName(uint32_t ulInput)
{
    ...
}
/* *********************************************************************/
/* End      :  prvFunctionName                                         */
/* *********************************************************************/

######Code: Example of a function header

####Gists

• Datatypes
• Headerfile
• Sorcefile
• function

##Comments

/* Comments are made like this */

only use double slash (//) comments for commenting out code parts

##Layout