HC-SR04,16F877A 7segment LED display

[Julian1971]

Hello!
I am new to programming microcontrollers! I use the code of int.electrosome.com for the ultrasonic sensor HC-SR04. My point to you is that the ultrasonic sensor readings can be multiplexed on a 4 digit 7 segment display with a common cathode, at 4 digits to I see the letter C. I use 16F877A with 8Mhz external oscillator.
Thanks in advance for your help!
With respect!
Julian

// LCD module connections
sbit LCD_RS at RD2_bit;
sbit LCD_EN at RD3_bit;
sbit LCD_D4 at RD4_bit;
sbit LCD_D5 at RD5_bit;
sbit LCD_D6 at RD6_bit;
sbit LCD_D7 at RD7_bit;

sbit LCD_RS_Direction at TRISD2_bit;
sbit LCD_EN_Direction at TRISD3_bit;
sbit LCD_D4_Direction at TRISD4_bit;
sbit LCD_D5_Direction at TRISD5_bit;
sbit LCD_D6_Direction at TRISD6_bit;
sbit LCD_D7_Direction at TRISD7_bit;
// End LCD module connections

int a;

//Interrupt function will be automatically executed on Interrupt
void interrupt()
{
if(INTCON.RBIF == 1) //Makes sure that it is PORTB On-Change Interrupt
{
INTCON.RBIE = 0; //Disable On-Change Interrupt
if(PORTB.F4 == 1) //If ECHO is HIGH
T1CON.F0 = 1; //Start Timer
if(PORTB.F4 == 0) //If ECHO is LOW
{
T1CON.F0 = 0; //Stop Timer
a = (TMR1L | (TMR1H<<8))/58.82; //Calculate Distance
}
}
INTCON.RBIF = 0; //Clear PORTB On-Change Interrupt flag
INTCON.RBIE = 1; //Enable PORTB On-Change Interrupt
}

void main()
{
char txt[7];
Lcd_Init();
Lcd_Cmd(_LCD_CLEAR); // Clear display
Lcd_Cmd(_LCD_CURSOR_OFF); // Cursor off

TRISB = 0b00010000;
INTCON.GIE = 1; //Global Interrupt Enable
INTCON.RBIF = 0; //Clear PORTB On-Change Interrupt Flag
INTCON.RBIE = 1; //Enable PORTB On-Change Interrupt

Lcd_Out(1,1,"Developed By");
Lcd_Out(2,1,"electroSome");

Delay_ms(3000);
Lcd_Cmd(_LCD_CLEAR);

T1CON = 0x10; //Initializing Timer Module

while(1)
{
TMR1H = 0; //Setting Initial Value of Timer
TMR1L = 0; //Setting Initial Value of Timer

a = 0;

PORTB.F0 = 1; //TRIGGER HIGH
Delay_us(10); //10uS Delay
PORTB.F0 = 0; //TRIGGER LOW

Delay_ms(100); //Waiting for ECHO
a = a + 1; //Error Correction Constant
if(a>2 && a<400) //Check whether the result is valid or not
{
IntToStr(a,txt);
Ltrim(txt);
Lcd_Cmd(_LCD_CLEAR);
Lcd_Out(1,1,"Distance = ");
Lcd_Out(1,12,txt);
Lcd_Out(1,15,"cm");
}
else
{
Lcd_Cmd(_LCD_CLEAR);
Lcd_Out(1,1,"Out of Range");
}
Delay_ms(400);
}
}