====Objectives====
To build a binary counter using LEDs and a raspberry pi

====Prerequisites====
 raspberry pie,monitor, keyboard, data cable, hdmi to usb cable, network cable

====Background====
The Raspberry Pi is a credit-card-sized single-board computer developed in the UK by the Raspberry Pi Foundation with the intention of promoting the teaching of basic computer science in schools.[7][8][9][10][11]

The Raspberry Pi is manufactured through licensed manufacturing deals with Newark element14 (Premier Farnell), RS Components and Egoman. All of these companies sell the Raspberry Pi online.[12] Egoman produces a version for distribution solely in China and Taiwan, which can be distinguished from other Pis by their red coloring and lack of FCC/CE marks. The hardware is the same across all manufacturers.

====Code====

<code>

#include "rpi.h"

void clear()
{
	GPIO_CLR = 1 << 7;
	GPIO_CLR = 1 << 8;
	GPIO_CLR = 1 << 9;
	GPIO_CLR = 1 << 10;
	sleep(1); 
}
int main()
{
  if(map_peripheral(&gpio) == -1)
  {
    printf("Failed to map the physical GPIO registers into the virtual memory space.\n");
    return -1;
  }
int count = 0;

// Define pin 7 as output
  INP_GPIO(7);
  OUT_GPIO(7);
  INP_GPIO(8);
  OUT_GPIO(8);
  INP_GPIO(9);
  OUT_GPIO(9);
  INP_GPIO(10);
  OUT_GPIO(10);
  
  
    // Toggle pin 7 (blink a led!)

//15
	GPIO_SET = 1 << 7;
    GPIO_SET = 1 << 8;
	GPIO_SET = 1 << 9;
	GPIO_SET = 1 << 10;
	
	sleep(2);

	clear();

//14
	GPIO_SET = 1 << 7;
	 GPIO_SET = 1 << 8;
	 GPIO_SET = 1 << 9;
	 GPIO_SET = 0 << 10;
	   

	sleep(2);
	clear();
//13      
	  GPIO_SET = 1 << 7;
      GPIO_SET = 1 << 8;
	  GPIO_SET = 0 << 9;
	  GPIO_SET = 1 << 10;

	 sleep(2);
	clear();
	   
	  GPIO_SET = 1 << 7;
	  GPIO_SET = 1 << 8; 
	  GPIO_SET = 0 << 9;
	  GPIO_SET = 0 << 10;

	 sleep(2);
	clear();									     
	    
	 GPIO_SET = 1 << 7;
	 GPIO_SET = 0 << 8;  
     GPIO_SET = 1 << 9;
     GPIO_SET = 1 << 10;
					   
	 sleep(2);
	 clear();    
																	
	 GPIO_SET = 1 << 7;
      GPIO_SET = 0 << 8;  
      GPIO_SET = 1 << 9;
      GPIO_SET = 0 << 10;

     sleep(2);
    clear();    

	 GPIO_SET = 1 << 7;
      GPIO_SET = 0 << 8;  
      GPIO_SET = 0 << 9;
      GPIO_SET = 1 << 10;

     sleep(2);
    clear();    

	 GPIO_SET = 1 << 7;
      GPIO_SET = 0 << 8;  
      GPIO_SET = 0 << 9;
      GPIO_SET = 0 << 10;

     sleep(2);
    clear();    

	 GPIO_SET = 0 << 7;
      GPIO_SET = 1 << 8;  
      GPIO_SET = 1 << 9;
      GPIO_SET = 1 << 10;

     sleep(2);
    clear();    

 GPIO_SET = 0 << 7;
      GPIO_SET = 1 << 8;  
      GPIO_SET = 1 << 9;
      GPIO_SET = 0 << 10;

     sleep(2);
    clear();    


 GPIO_SET = 0 << 7;
      GPIO_SET = 1 << 8;  
      GPIO_SET = 0 << 9;
      GPIO_SET = 1 << 10;

     sleep(2);
    clear();    

 GPIO_SET = 0 << 7;
      GPIO_SET = 1 << 8;  
      GPIO_SET = 0 << 9;
      GPIO_SET = 0 << 10;

     sleep(2);
    clear();    

 GPIO_SET = 0 << 7;
      GPIO_SET = 0 << 8;  
      GPIO_SET = 1 << 9;
      GPIO_SET = 1 << 10;

     sleep(2);
    clear();    

 GPIO_SET = 0 << 7;
      GPIO_SET = 0 << 8;  
      GPIO_SET = 1 << 9;
      GPIO_SET = 0 << 10;

     sleep(2);
    clear();    

 GPIO_SET = 0 << 7;
      GPIO_SET = 0 << 8;  
      GPIO_SET = 0 << 9;
      GPIO_SET = 1 << 10;

     sleep(2);
    clear();    
 GPIO_SET = 0 << 7;
      GPIO_SET = 0 << 8;  
      GPIO_SET = 0 << 9;
      GPIO_SET = 0 << 10;

     sleep(2);
    clear();    


  return 0;
}

</code>

====Reflection====
even though this was a cheesy counter program it was really neat to see the counter work!!