// Alex Rodríguez Navas, David Marín Gutiérrez, Carlos Sansón Martín

#include <xc.h>
#include "config.h"
#define _XTAL_FREQ 8000000

int watchdog = 0;
int updown = 0;

void setup(void) {
   TRISCBits.RC2 = 0; // Pin RC2 a output

   // Interrupts
      IPEN = 0; // Todas las interrutps son high priority
      GIE = 1; // Habilitar interrupts de high priority y las unmasked
      PEIE = 1; // Habilitar todas las interrupts perifericas unmasked

   // Timer 2
      TMR2IF = 0; // Timer 2 interrupt flag
      TMR2IE = 1; // Timer 2 enable interrupt flag
      TMR2IP = 1; // Timer 2 interrupt priority
      T2CKPS0 = 0; // Timer 2 prescaler 1:16
      T2CKPS1 = 1; // Timer 2 prescaler 1:16
      PR2 = 124; // Timer 2 period register a 124 pq PRx = period*(Fosc/4*prescaler*postcaler)-1
         // period = 1ms, prescaler = 16, postcaler = 1 ==> PRx = 124 (postcaler is 1 for PWM because ignored)
   // CCP1
      CCP1M0 = 0; // CCP Mode select bits
      CCP1M1 = 0; // 11xx PWM mode
      CCP1M2 = 1;
      CCP1M3 = 1;
      DC1B0 = 0; // Bits bajos del PWM Duty Cycle del CCP1
      DC1B1 = 0;
      CCPR1L = 0; // Bits altos del PWM Duty Cycle del CCP1
      /*
		1 = CCP1/4*(124+1)
		CCP1 = 500 ==> CCP1L = 125 (0x7D) DC1B = 0 (0x0)
		Timer2 tick cada 1ms, en 1000ms 0%->100% ==> cada 8 ms CCP1L++

		pulseWidth = CCPRxL:DCxB0~1 * TOSC * prescaler
		dutyCycleRatio = (CCPRxL:DCxB0~1)/4*(PRx+1)
      */

   // Timer 2-bis
      TMR2ON = 1; // Timer 2 enable
}

void interrupt rutina_AP(void) {
   if (TMR2IF && TMR2IE) {
	  watchdog++;
	  if (watchdog == 8) { // 8ms
		if (updown <= 125) CCPR1L++; // 1s 0->125
		else CCPR1L--; // 1s 125->0
		updown++;
		watchdog = 0;
	  }

      TMR2IF = 0; // Clear Timer 2 interrupt flag
   }
}

void loop(void) {
}

void main(void)
 {
   setup();
   while (1) loop();
 }