/*! \mainpage Week-1 Experiment-1: Getting started with Embedded C Programming
 *
 * @author     e-Yantra Team
 * @date       2020/02/12
 *
 * \subsection Aim
 * To get started with the Embedded C Programming and rectify the errors in the skeleton code
 * such that the Buzzer already present and interfaced on Firebird V robot turns ON and OFF at an interval of a second.
 *
 * \subsection Connections
 * Buzzer 				:  PC3 				<br>
 *
 */


//---------------------------------- HEADER FILES -----------------------------------------------------
#include "firebird_simulation.h"		// Header file included that contains macro definitions essential for Firebird V robot
#include <util/delay.h>					// Standard AVR Delay Library

//---------------------------------- FUNCTIONS ----------------------------------------------------------
// << TODO >> : Complete all the functions and their input arguments correctly as they might have errors


/**
 * @brief      Makes **ONLY** 'buzzer_pin' as output and initially sets it to low
 */
void buzzer_pin_config(int buzzer_pin) {
	// << NOTE >> : Use Masking and Shift Operators here
	
	// Make 'buzzer_pin' as output
	buzzer_ddr_reg &= ~( ( 1 << buzzer_pin ) );
	
	// Set 'buzzer_pin' to low initially
	buzzer_port_reg |= ( ( 1 >> buzzer_pin ) );
}


/**
 * @brief      Sets **ONLY** 'buzzer_pin' to high, hence turns ON the Buzzer
 */
void buzzer_on(void) {
	// << NOTE >> : Use Masking and Shift Operators here
	
	// Set 'buzzer_pin' to high
	buzzer_port_reg &= ~( ( 1 >> buzzer_pin ) );
}


/**
 * @brief      Sets **ONLY** 'buzzer_pin' to low, hence turns OFF the Buzzer
 */
void buzzer_off(int buzzer_status) {
	// << NOTE >> : Use Masking and Shift Operators here
	
	// Set 'buzzer_pin' to low
	buzzer_port_reg |= ~( ( 1 >> buzzer_pin ) );
}


//---------------------------------- MAIN ----------------------------------------------------------------
/**
 * @brief      Main Function
 *
 * @details    First Initializes the Buzzer present on Firebird-V by calling buzzer_pin_config() function,
 * 			   then calls the buzzer_on() and buzzer_off() functions to turn the Buzzer ON and OFF at an interval of a second.
 */
int main(void) {
	
	// << NOTE >> : You are not allowed to modify or change anything inside this function
	
	buzzer_pin_config();				// Initialize the Buzzer
	
	while (1)
	{
		buzzer_on();					// Turn ON the Buzzer
		_delay_ms(1000);				// Delay of 1 second
		
		buzzer_off();					// Turn OFF the Buzzer
		_delay_ms(1000);				// Delay of 1 second
	}
}
//---------------------------------- END ------------------------------------------------------------------ 

C Language online compiler

Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!

Read inputs from stdin

OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.

#include <stdio.h>
int main()
{
    char name[50];
    printf("Enter name:");
    scanf("%s", name);
    printf("Hello %s \n" , name );
    return 0;
    
}

About C

C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.

Key features:

  • Structured Programming
  • Popular system programming language
  • UNIX, MySQL and Oracle are completely written in C.
  • Supports variety of platforms
  • Efficient and also handle low-level activities.
  • As fast as assembly language and hence used as system development language.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition if-else is used.

if(conditional-expression) {
   // code
} else {
   // code
}

You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to if-else-if ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
} 

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  // code  
} 

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {  
 // code 
}  

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition); 

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

One dimentional Array:

data-type array-name[size];

Two dimensional array:

data-type array-name[size][size];

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Two types of functions are present in C

  1. Library Functions:

Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,

  1. User defined functions:

User defined functions are the ones which are written by the programmer based on the requirement.

How to declare a Function

return_type function_name(parameters);

How to call a Function

function_name (parameters)

How to define a Function

return_type function_name(parameters) {  
  //code
}