Counting the number of times pressed of Switch , C program in MPLAB X

In this program we are going to count the number of times a switch pressed,and displaying it on a LCD .. and each time the switch pressed a LED will lighted up.

First create a new project and add a c main file like in the  steps for  Blinking a LED using MPLAB X , PIC16F877A

Components 


1. PIC16F877A micro controller
2. animated LED  
3. A toggle switch
4.16x2 LCD display




Steps in the program

1. define the ports for easy usage 

Defines the control pins of LCD to the 0th,1st and 2nd pin of PORT D
    #define RS RD0
    #define RW RD1
   #define EN RD2
Defines the data port of the  LCD to PORT B
   #define DATA PORTC
Defines switch in the 0th pin of PORT C
   #define S RC0
Defines LED on the 3rd pin of PORT D
   #define L RD3

2. Function declarations .. here we declare 3 functions  and all the 3 functions is for LCD

void LCD_CMD(unsigned int value); //This function is pass the LCD commands

void LCD_DAT(unsigned int value); // this is for pass the DATA to the LCD which is to displayed 

void LCD_INIT(); //this to initialize the LCD

void delay(); // this is to delay the LCD commands 

for more refer the    Interfacing LCD with PIC16F877A in MPLAB X

3. next is main function .. in main function we make 

•  PORT C as input where we have connected the switch
•  PORT D as output where we have connected the LED and control pins of LCD
• PORT B as outout where we have connected DATA pins of LCD

    TRISC  =0x0F;

    TRISD  =0x00;

    TRISB = 0x00;

4. The function LCD_INIT(); is called for initializing the LCD

5. Declared a variable called count, and initialized it to zero

   int count;

   count=0;

6.  we put the LED off 

7. now we are going for a infinite loop by 

    while(1)

    { 

     }

8. In the loop we are checking switch is ON or OFF condition

 if the switch is ON ; LED is on and count is incremented by 1 and display the value of count in LCD 

if the Switch is OFF it wait for the condition when the Switch is ON 

schematic diagram 

full Program

 ###################################################################################

    /*

 * File:   switchcount.c
 * Author: Ebin Ephrem
 
 */

#include<htc.h>

__CONFIG(0x193A);

C

#define RS RD0

#define RW RD1

#define EN RD2

#define DATA PORTB

#define S RC0

#define L RD3

void LCD_CMD(unsigned int value);

void LCD_DAT(unsigned int value);

void LCD_INIT();

void delay();

void main(void)

{

    TRISC  =0x0F;

    TRISD  =0x00;

    TRISB = 0x00;

LCD_INIT();

int count;

count=0;

L=0;

  while(1)

  {

if( S == 1)

       {

    while(S==1);

            L= ~L;

                     count = count+1;

              LCD_CMD(0x01);

        delay ();

    LCD_DAT('0' + (count % 10));

}

       }

 }

void LCD_INIT()

 {

    LCD_CMD(0x01);

    delay ();

    LCD_CMD(0x38);

    delay ();

    LCD_CMD(0x0F);

    delay ();

    LCD_CMD(0x06);

    delay ();

    LCD_CMD(0x0c);

    delay ();

    LCD_CMD(0x80);

    delay ();

}

void LCD_CMD(unsigned int  value)

{

    DATA =  value;

    RS=0;

    RW=0;

    EN=1;

    delay ();

    EN=0;

    delay ();

 }

void LCD_DAT(unsigned int value)

{

    DATA= value ;

    RS=1;

    RW=0;

    EN=1;

    delay ();

    EN=0;

    delay();

}

void delay(void)

{

    int counter = 0;

    for (counter = 0; counter<1000; counter++) {

        ;

    }

}