[PIC] pulse counter with pic 16f887 using interupts

// Define LCD module connections.
 sbit LCD_RS at RD4_bit;
 sbit LCD_EN at RD5_bit;
 sbit LCD_D4 at RD0_bit;
 sbit LCD_D5 at RD1_bit;
 sbit LCD_D6 at RD2_bit;
 sbit LCD_D7 at RD3_bit;
 sbit LCD_RS_Direction at TRISD4_bit;
 sbit LCD_EN_Direction at TRISD5_bit;
 sbit LCD_D4_Direction at TRISD0_bit;
 sbit LCD_D5_Direction at TRISD1_bit;
 sbit LCD_D6_Direction at TRISD2_bit;
 sbit LCD_D7_Direction at TRISD3_bit;
// End LCD module connection definition
// Define Messages
 
unsigned long noOfOverflows = 0, startTime = 0, endTime = 0, pulse_ticks = 0, rpm = 0, rps = 0, oldVal = 0;
char count = 0, display = 0, sendTime[23], sRPM[23], msg[] = "CPM = ";
double rpm2 = 0.0;

void Interrupt(){
    if(TMR1IF_bit){
         noOfOverflows++;
                  //counts 65536 before each overflow
         TMR1IF_bit = 0;          //Fosc = 8 MHz, Timer OSC = 8 MHz / 4 = 2 MHz                                  //TMR1 T = 1 / 2 MHz =  0.5 us
                                  //0.5 us = 1 tick, 32767.5 ticks in 1 sec
    }                             //1966050 ticks in 60 sec
    
    if(CCP1IF_bit){
        count++;

        if(count == 1){
                 CCP1IF_bit = 0;
                 startTime = CCPR1; //(65536 * noOfOverflows) + CCPR1;
                 noOfOverflows = 0;
        }
        if(count == 2){
                 CCP1IE_bit = 0;
                 CCP1IF_bit = 0;
                 display = 1;

        }
    }
}

 void main() {
    TRISC = 0xFF;
    PORTC = 1;
    T1CON = 0b10001000;
    CCP1CON = 0b00000101;
    INTCON = 0xC0;
    TMR1IE_bit = 1;
    TMR1ON_bit = 1;
    CCP1IE_bit = 1;
  Lcd_Init();                      // Initialize LCD
  
  Lcd_Cmd(_LCD_CLEAR);             // CLEAR display
  
  Lcd_Cmd(_LCD_CURSOR_OFF);
  
  while(1) {        // Cursor off
/*Lcd_Out(1,4,message1);            // Write message1 in 1st row
   Lcd_Out(2,1,message2);           // Write message2 in 2nd row
   Delay_ms(1000);                       // Wait for 1 sec
   Lcd_Cmd(_LCD_CLEAR);     // Clear display
   Delay_ms(1000); // Wait for 1 sec*/
    if(display){
                endTime = (65536 * noOfOverflows) + CCPR1;   //On second CCP1IF save time to endTime
                endTime = endTime - startTime;               //Take difference of time.
                rpm = 120e6 / endTime;
                rps = rpm / 60;
                //rpm2 = (float)rpm;
                noOfOverflows = 0;
                    
                if(oldVal != rpm) {
                    LongToStr(rpm, sRPM);
                    LCD_Out(2,7, "           ");
                    LCD_Out(2,7, sRPM);
                    
                    oldVal = rpm;
                }
                
                endTime = 0;
                startTime = 0;
                count = 0;
                display = 0;
                CCP1IE_bit = 1;
    }
  }              // Infinite Loop
 }