PIC16F877A – Interfacing LED

PIC16F877A Mini Development Board has 3 SMD LEDs connected to port pins RB1, RB2 and RB3 via jumpers J1, J2 and J10 respectively. If any jumper is left open, then the corresponding port pin can be used independently.The sample code given below toggles the LEDs in fixed intervals. Jumpers (J1/J2/J10) have to be shorted accordingly for using the desired LED.

Schematic

Sample Code

/*************************************************************************
                              HEADER FILES
**************************************************************************/
#include<pic.h>		

/*************************************************************************
                          FUNCTION DECLARATIONS
**************************************************************************/
void Delay_Ms(unsigned int);

/*************************************************************************
                              MAIN FUNCTION
**************************************************************************/
void main()
{
 TRISB=0x00;              /* PORTB configured as o/p                     */
 while(1)
 {
  PORTB=0xFF;             /* Make port pins high to turn on LEDs         */
  Delay_Ms(500);          /* Delay fuction called for 500ms              */
  PORTB=0x00;             /* Make port pins low to turn off LEDs         */
  Delay_Ms(500);          /* Delay fuction called for 500ms              */ 
 }
}

/*************************************************************************
* Function    : Delay_Ms                                                 *
*                                                                        *
* Description : Function for delay                                       *
*                                                                        *
* Parameter   : ms - delay in milliseconds                               *
**************************************************************************/
void Delay_Ms(unsigned int ms)
{
 int i,count;
 for(i=1; i<=ms; i++)
 {
  count = 498;
  while(count != 1)
  {
   count--;
  }
 }
}

/***************************  END OF PROGRAM  ****************************/