/**
 * Simple Real time clock example by Garth Klee.
 * If run on PICDEM2+, time will be displayed
 * on LCD and will incorporate LED pendulum.
 * Has been written to run on PIC16F87x/A
 */

#include <htc.h>
#include <stdio.h>
#include "lcd.h"
#include "rtc.h"

__CONFIG(XT & WDTDIS & LVPDIS & DEBUGEN);

volatile near unsigned char tickCounter;
volatile near unsigned char newSecond;

near unsigned char hours;
near unsigned char minutes;
near unsigned char seconds;
near bit ampm;

// Pendulum pattern to display on LEDs (RB0:3)
const unsigned char pattern[] = {1,2,4,8,4,2};

void init(void){
    /***** Common Code ****
     *  Timer 2 interrupt enabled.
     */
    PIE1    = 0b00000010;
    /*
     *  Peripheral interrupts enabled
     *  Global interrupt disabled during initialization
     */
    INTCON  = 0b01000000;

    /***** Timer 2 Code ****
     *  Prescale ratio set at 1:16
     *  Timer2 module activated
     *  Postscale ratio set at 1:10
     */
    T2CON   = 0b01001110;
    /*
     *  Period register set to 0xF9
     */
    PR2 = 0b11111001;

#if PENDULUM == ON
    TRISB = 0;
#endif
#if ((TICKING == ON)||(ALARM == ON))
    TRISC2=0;
#endif

    ei();   // Global interrupts enabled
}

void main(void){
    init();
#if SCREEN == ON
    lcd_init();
#endif

    newSecond = tickCounter = 0;

    // Initialise the current time
    hours = START_H;
    minutes = START_M;
    seconds = START_S;
    ampm = START_AP;

    // Measure time
    while(1){
        if(newSecond){
            // A second has accumulated, count it
            newSecond--;
            if(++seconds > 59){
                seconds=0;
                if(++minutes > 59){
                    minutes = 0;
                    hours++;
                    if(hours == 12)
                        ampm^=1;
                    if(hours>12)
                        hours=1;
                }
            }

#if SCREEN == ON
            // print time on LCD screen
            lcd_goto(0);
            lcd_puts("Time=");
            // Print hours
            if(hours/10)
                lcd_putch('1');
            else
                lcd_putch(' ');
            lcd_putch((hours%10)+'0');
            lcd_putch(':');
            // print minutes
            lcd_putch((minutes/10)+'0');
            lcd_putch((minutes%10)+'0');
            lcd_putch(':');
            // print seconds
            lcd_putch((seconds/10)+'0');
            lcd_putch((seconds%10)+'0');
            if(ampm)
                lcd_putch('P');
            else
                lcd_putch('A');
            lcd_putch('M');
#endif

#if PENDULUM == ON
            // Rotate LED pattern every second
            PORTB=(pattern[seconds%sizeof(pattern)]);
#endif
#if TICKING == ON
            RC2^=1; // tick effect
#endif

        }
#if ALARM == ON
        // If time matches alarm setting, toggle RC2
        if((hours == ALARM_H) &&
                (minutes == ALARM_M) &&
                (ampm == ALARM_AP)&&
                (seconds < ALARM_LENGTH)){
            unsigned int tone;
            RC2 ^= 1;   // generate buzz
            tone=TONE2;
            if(seconds&1)
                tone=TONE1;
            while(tone--)continue;  // tone generation
            RC2 ^= 1;   // generate buzz
        }
#endif
    }
}

void interrupt isr(void){
        /***** Timer 2 Code *****/
    if((TMR2IE)&&(TMR2IF)){
        // Interrupt period is 40 mSec, 25 interrupts = 1 Sec
        if(++tickCounter == 25){
            tickCounter=0;
            newSecond++;    // Notify a second has accumulated
        }
        TMR2IF=0;   // clear event flag
    }
}