My first C program

twinkle.c

// PIC16F887 Configuration Bit Settings

// 'C' source line config statements
#define _XTAL_FREQ 4000000
#include <xc.h>
#include <stdlib.h>
#include <stdio.h>
// #pragma config statements should precede project file includes.
// Use project enums instead of #define for ON and OFF.

// CONFIG1
#pragma config FOSC = HS        // Oscillator Selection bits 
#pragma config WDTE = OFF        // Watchdog Timer Enable bit (WDT not enabled)
#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = ON       // RE3/MCLR pin function select bit (RE3/MCLR pin function is MCLR)
#pragma config CP = OFF         // Code Protection bit (Program memory code protection is disabled)
#pragma config CPD = OFF        // Data Code Protection bit (Data memory code protection is disabled)
#pragma config BOREN = ON       // Brown Out Reset Selection bits (BOR enabled)
#pragma config IESO = ON        // Internal External Switchover bit (Internal/External Switchover mode is enabled)
#pragma config FCMEN = ON       // Fail-Safe Clock Monitor Enabled bit (Fail-Safe Clock Monitor is enabled)
#pragma config LVP = ON         // Low Voltage Programming Enable bit (RB3/PGM pin has PGM function, low voltage programming enabled)

// CONFIG2
#pragma config BOR4V = BOR40V   // Brown-out Reset Selection bit (Brown-out Reset set to 4.0V)
#pragma config WRT = OFF        // Flash Program Memory Self Write Enable bits (Write protection off)



void C(double duration){
    int reps = 1046*duration;
    PORTA = 0xFF;
    for (int i=0; i<reps;i++){
    RC2 = 1;
    __delay_us(465);
    RC2 = 0;
    __delay_us(464);
    }
    PORTA = 0;
    //mean scope freq: 1046 Hz
}

void D(double duration){
    int reps = 1174*duration;
    PORTB = 0xFF;
    for (int i=0; i<reps;i++){
    RC2 = 1;
    __delay_us(413);
    RC2 = 0;
    __delay_us(412);
    }
    PORTB = 0;
    //mean scope freq: 1,173.6 Hz
}

void E(double duration){
    int reps = 1318*duration;
    PORTB = 0xFF;
    for (int i=0; i<reps ;i++){
    RC2 = 1;
    __delay_us(366);
    RC2 = 0;
    __delay_us(365);
    }
    PORTB = 0;
    //mean scope freq: 1,318.3
}

void F(double duration){
    int reps = 1396*duration;
    PORTA = 0xFF;
    for (int i=0; i<reps ;i++){
    RC2 = 1;
    __delay_us(346);
    RC2 = 0;
    __delay_us(345);
    }
    PORTA = 0;
    //mean scope freq: 1,393 Hz
}

void G(double duration){
    int reps = 1567*duration;
    PORTB = 0xFF;
    for (int i=0; i<reps ;i++){
    RC2 = 1;
    __delay_us(306);
    RC2 = 0;
    __delay_us(306);
    }
    PORTB = 0;
    //mean scope freq: 1,566.9 Hz
}

void A(double duration){
    int reps = 1760*duration;
    PORTA = 0xFF;
    for (int i=0; i<reps ;i++){
    RC2 = 1;
    __delay_us(271);
    RC2 = 0;
    __delay_us(270);
    }
    PORTA = 0x00;
    //mean scope freq: 1,760.1 Hz
}

void main(){
    TRISC = 0;
    TRISA = 0;
    TRISB = 0;
    ANSEL, ANSELH = 0;
    PORTC = 0;
    while (1){
       
        C(.5);
        __delay_ms(100);
        C(.5);
        __delay_ms(100);
        G(.5);
        __delay_ms(100);
        G(.5);
        __delay_ms(100);
        A(.5);
        __delay_ms(100);
        A(.5);
        __delay_ms(100);
        G(1);
        __delay_ms(100);
        F(.5);
        __delay_ms(100);
        F(.5);
        __delay_ms(100);
        E(.5);
        __delay_ms(100);
        E(.5);
        __delay_ms(100);
        D(.5);
        __delay_ms(100);
        D(.5);
        __delay_ms(100);
        C(1);
        __delay_ms(100);
        G(.5);
        __delay_ms(100);
        G(.5);
        __delay_ms(100);
        F(.5);
        __delay_ms(100);
        F(.5);
        __delay_ms(100);
        E(.5);
        __delay_ms(100);
        E(.5);
        __delay_ms(100);
        D(1);
        __delay_ms(100);
        G(.5);
        __delay_ms(100);
        G(.5);
        __delay_ms(100);
        F(.5);
        __delay_ms(100);
        F(.5);
        __delay_ms(100);
        E(.5);
        __delay_ms(100);
        E(.5);
        __delay_ms(100);
        D(1);
        __delay_ms(100);
        C(.5);
        __delay_ms(100);
        C(.5);
        __delay_ms(100);
        G(.5);
        __delay_ms(100);
        G(.5);
        __delay_ms(100);
        A(.5);
        __delay_ms(100);
        A(.5);
        __delay_ms(100);
        G(1);
        __delay_ms(100);
        F(.5);
        __delay_ms(100);
        F(.5);
        __delay_ms(100);
        E(.5);
        __delay_ms(100);
        E(.5);
        __delay_ms(100);
        D(.5);
        __delay_ms(100);
        D(.5);
        __delay_ms(100);
        C(1);
        __delay_ms(10000); 
        
                
        
    
    }
}