/*
 Alessandro Lambardi 14/02/2009
 Released under Creative Commons 3.0 license: Attribution, Share-alike, non commercial.
*/

#define F_CPU	2457600UL	// crystal frequency

#include <stdlib.h>
#include <avr/interrupt.h>
#include <avr/io.h>
#include <avr/pgmspace.h>
#include <inttypes.h>

#define JUMP_0	0 		// PORTA, jumper, display ceconds
#define JUMP_1	1 		// PORTA, jumper, set minutes
#define JUMP_2	2 		// PORTA, jumper, set hours
#define JUMP_3	3 		// PORTA, short for continuos LASER

#define SERVO	5		// PORTA, output to servo
#define LASER	6		// PORTA, output to LASER
#define PWM_TOP	F_CPU/60// TOP count for timer 0 (goes into OCR0A)

//#define SERVO_MAX	PWM_TOP*2.35/(1000/60)	// max rotation is at 2.35ms pulse
//#define SERVO_MIN	PWM_TOP*0.70/(1000/60)		// min rotation is at 0.70ms pulse
#define SERVO_MAX	PWM_TOP*1.65/(1000/60)	// max rotation is at 2.35ms pulse
#define SERVO_MIN	PWM_TOP*0.75/(1000/60)		// min rotation is at 0.70ms pulse

// Variables that are set inside interrupt routines and watched outside must be volatile
volatile uint8_t	hour, min, sec, sxtyth;	// hold the time
volatile uint16_t	servo_pos;	// servo position (0 to PWM_TOP) ref to 00:00
volatile uint16_t	servo_max, servo_min;	// max/min value to servo for max/min position
volatile uint8_t	jumpers;


// Interrupt service routines
ISR(TIM1_OVF_vect) {			//  do time

	sxtyth++;

	if(sxtyth < 6) {	// blink LASER for 2/10 of a sec
		PORTA |= _BV(LASER);
	}
	else{
		if((PINA & _BV(JUMP_3)) != 0) {	// if JUMP_3 not shorted turn LASER off
			PORTA &= ~_BV(LASER);
		}
	}

	if(sxtyth > 59){
		sxtyth = 0;
		sec++;
		if(sec > 59){
			sec = 0;
			min++;
			if(min > 59){
				min = 0;
				hour++;
				if(hour > 12){
					hour = 1;
				}
			}
		}
	}

	// set time :
	// set minutes
	if(((PINA & _BV(JUMP_1)) == 0) & ((sxtyth == 0) | (sxtyth == 30))){
		min++;
		if(min > 59) {
			min = 0;
		}
		sec = 0;
	}
	// set hours
	if(((PINA & _BV(JUMP_2)) == 0) & ((sxtyth == 0) | (sxtyth == 30))){
		hour++;
		if(hour > 12) {
			hour = 1;
		}
		min = 0;
		sec = 0;
	}

	if((PINA & _BV(JUMP_0)) == 0){	// evaluate servo position and display time
		servo_pos = servo_min + sec*((servo_max-servo_min)/59);	// display seconds
	} else {
		servo_pos = servo_min + ((hour-1)*60+min)*((servo_max-servo_min)/(11*60+59));
	}

	OCR1B = servo_min+servo_max-servo_pos;	// clockwise
//	OCR1B = servo_pos;	// counter clockwise

}

int main(void) {

// enable pull-ups on pushbuttons
	PORTA = _BV(JUMP_0) | _BV(JUMP_1) | _BV(JUMP_2) | _BV(JUMP_3);

// Port directions
	DDRA = _BV(SERVO) | _BV(LASER);		// set outputs

// Timer 1 (servo PWM): fast PWM mode 15, prescaler = 1, output on OC1B
	TCCR1A = _BV(WGM11) | _BV(WGM10) | _BV(COM1B1);
	TCCR1B = _BV(WGM13) | _BV(WGM12) | _BV(CS10);

	OCR1A = PWM_TOP;		// PWM freq = 60Hz
	OCR1B = (SERVO_MAX + SERVO_MIN)/2;// initial position is halfway between MAX & MIN

	TIMSK1 = _BV(TOIE1);	// enable timer overflow (for real time clock)

// Set variables default
	hour = 1;
	min = 0;
	sec=0;
	sxtyth=0;

	servo_min=SERVO_MIN;
	servo_max=SERVO_MAX;

	sei();			// enable interrupts

	for(;;) {
	}
}