//Code to make my funky, wire coat hanger clock
//The code is taken from the 3LED_clock project
//Edited 2 April 2005
//Came back 11 Feb 2006
//Corrected time 14 Mar 2006

#include <16F877.h>
#fuses XT,NOWDT,NOPROTECT,PUT
#include <stdlib.h>
#use delay(clock=2000000)

#define TENHOUR PIN_C3

#define HOUR1 PIN_A5
#define HOUR2 PIN_E0
#define HOUR3 PIN_A3
#define HOUR4 PIN_A2
#define HOUR5 PIN_A1
#define HOUR6 PIN_E2
#define HOUR7 PIN_E1

#define COLON PIN_C1

#define TEN1 PIN_B7
#define TEN2 PIN_B6
#define TEN3 PIN_B0
#define TEN4 PIN_B1
#define TEN5 PIN_B2
#define TEN6 PIN_B4
#define TEN7 PIN_B5

#define MIN1 PIN_D7
#define MIN2 PIN_D6
#define MIN3 PIN_C5
#define MIN4 PIN_C6
#define MIN5 PIN_C7
#define MIN6 PIN_D4
#define MIN7 PIN_D5

#define SETHOUR PIN_D1
#define SETTEN PIN_D3
#define SETMIN PIN_D2
// Each digit is drawn with this set of named segments:
//
//   111111
//   6    2
//   6    2
//   777777
//   5    3
//   5    3
//   444444     


static int8 hours = 12;		//times are reprented this way: 11:37
static int8 tens = 0;		//hours = 11, tens = 3, minutes = 7
static int8 minutes = 0;

#INT_TIMER0
time_keeper()
{
	//this is called every 16.384ms: 2.000MHz, 4 cycles, 256 overflow, 32 pre-scaler
	// need to count 3662 per minute
	// setting it to 3662 made the clock get 1+sec ahead per hour, so changed to 3663

  static int16 count=0;
  static int16 correction=0;
  static int8 flash=0;

  count++;

  if (count%61 == 0)  //flash the colon between the numbers on and off each second
  {
    if (flash==0)
    {
      output_high(COLON);
      flash=1;
    }
    else
    {
      output_low(COLON);
      flash=0;
    }
  }
  
  if (count>=3663)	//a minute has gone by
  {
    count = 0;
    minutes++;

    if(minutes > 9)	//going from :19 to :20
    {
      minutes = 0;
      tens++;
      if(tens > 5)	//going from 3:59 to 4:00
      {
        tens = 0;
        hours++;
        if(hours > 12) hours = 1;
      }
    }
  }

  //Now to correct for the clock running 0.0194% too fast (gained 2 min 13 sec in 7days, 10.5 hours)
  correction++;
  if (correction==5157) //Inverse of 0.000194
  {
    count--;
    correction=0;
  }
}

void show_hour(int8 n)
{  //drawing the figure of the number segment by segment

  //first, does this hour start with the tens digit? 10,11 or 12
  if (n==10)
  {
    output_high(TENHOUR);
    n=0;
  }
  else if (n==11)
  {
    output_high(TENHOUR);
    n=1;
  }
  else if (n==12)
  {
    output_high(TENHOUR);
    n=2;
  }
  else 
    output_low(TENHOUR);

 
  if (n==1 || n==4)
    output_low(HOUR1);
  else 
    output_high(HOUR1);

  if (n==5 || n==6)
    output_low(HOUR2);
  else 
    output_high(HOUR2);

  if (n==2)
    output_low(HOUR3);
  else 
    output_high(HOUR3);

  if (n==1 || n==4 || n==7)
    output_low(HOUR4);
  else
    output_high(HOUR4);

  if (n==1 || n==3 || n==4 || n==5 || n==7 || n==9)
    output_low(HOUR5);
  else 
    output_high(HOUR5);

  if (n==1 || n==2 || n==3 || n==7)
    output_low(HOUR6);
  else 
    output_high(HOUR6);

  if (n==1 || n==7 || n==0)
    output_low(HOUR7);
  else
    output_high(HOUR7);
}

void show_ten(int8 n)
{  //drawing the figure of the number segment by segment

  if (n==1 || n==4)
    output_low(TEN1);
  else 
    output_high(TEN1);

  if (n==5 || n==6)
    output_low(TEN2);
  else 
    output_high(TEN2);

  if (n==2)
    output_low(TEN3);
  else 
    output_high(TEN3);

  if (n==1 || n==4 || n==7)
    output_low(TEN4);
  else
    output_high(TEN4);

  if (n==1 || n==3 || n==4 || n==5 || n==7 || n==9)
    output_low(TEN5);
  else 
    output_high(TEN5);

  if (n==1 || n==2 || n==3 || n==7)
    output_low(TEN6);
  else 
    output_high(TEN6);

  if (n==1 || n==7 || n==0)
    output_low(TEN7);
  else
    output_high(TEN7);
}

void show_minute(int8 n)
{  //drawing the figure of the number segment by segment

  if (n==1 || n==4)
    output_low(MIN1);
  else 
    output_high(MIN1);

  if (n==5 || n==6)
    output_low(MIN2);
  else 
    output_high(MIN2);

  if (n==2)
    output_low(MIN3);
  else 
    output_high(MIN3);

  if (n==1 || n==4 || n==7)
    output_low(MIN4);
  else
    output_high(MIN4);

  if (n==1 || n==3 || n==4 || n==5 || n==7 || n==9)
    output_low(MIN5);
  else 
    output_high(MIN5);

  if (n==1 || n==2 || n==3 || n==7)
    output_low(MIN6);
  else 
    output_high(MIN6);

  if (n==1 || n==7 || n==0)
    output_low(MIN7);
  else
    output_high(MIN7);
}

void alert_low_batt()
{	//Need to inform user that bettery is low.  
	//Spell out "Lo" on middle digits

  delay_ms(900);

  output_low(TENHOUR);

  output_low(HOUR1);
  output_low(HOUR2);
  output_low(HOUR3);
  output_high(HOUR4);
  output_high(HOUR5);
  output_high(HOUR6);
  output_low(HOUR7);

  output_low(TEN1);
  output_low(TEN2);
  output_high(TEN3);
  output_high(TEN4);
  output_high(TEN5);
  output_low(TEN6);
  output_high(TEN7);

  output_low(MIN1);
  output_low(MIN2);
  output_low(MIN3);
  output_low(MIN4);
  output_low(MIN5);
  output_low(MIN6);
  output_low(MIN7);

  delay_ms(1000);
}

main()
{
  //long voltage;
  //long v1, v2, v3;

	//setup ports
  set_tris_a(0B00000001);  //A0 input (ADC), all others output
  set_tris_b(0x00);  		//all pins output
  set_tris_c(0x00);
  set_tris_d(0b00001110);	//pins D1, D2 & D3 input (clock set)
  set_tris_e(0x00);

	//set ADC to read battery level
  setup_adc(ADC_CLOCK_DIV_32);
  setup_adc_ports(RA0_ANALOG);
  set_adc_channel(0);

	//start timer interrupt
  enable_interrupts(INT_TIMER0);
  enable_interrupts(GLOBAL);
  setup_timer_0(RTCC_DIV_32|RTCC_INTERNAL);
  set_timer0(0);


  while(true)
  {
    show_hour(hours);
	show_ten(tens);
	show_minute(minutes);
	
	delay_ms(100);
    
	//check if user is setting time.  I decided not to do this in an interrupt because of layout.
	if (input(SETHOUR)==0)
	{
	  hours++;
	  if (hours>12) hours=1;
	  show_hour(hours);
	  delay_ms(400);	//make sure user can let go of pin in time
	}
	else if (input(SETTEN)==0)
	{
	  tens++;
	  if (tens>5) tens=0;
	  show_ten(tens);
	  delay_ms(400);	//make sure user can let go of pin in time
	}	
	else if (input(SETMIN)==0)
	{
	  minutes++;
	  if (minutes>9) minutes=0;
	  show_minute(minutes);
	  delay_ms(400);	//make sure user can let go of pin in time
	}

	//check battery level
	if (read_adc()<153)	//battery power sampled halfway thru resistor bridge
	{					//Battery at 6V shows at 3V, compared to 5V ref, 153 on ADC out of 255 range
	  alert_low_batt();
	}
/*	while (true)	//Just in an effort to find what my ADC output range was,
	{				//I ended up making my own voltmeter!  That was easy!
					//Range is 0 - 255
		voltage = read_adc();
		v1 = voltage % 10;	//ones digit
		voltage = voltage - v1;
	    voltage = voltage/10;
		v2 = voltage % 10;	//tens digit
		voltage = voltage - v2;
	    voltage = voltage/10;
		v3 = voltage;	//hundreds digit
	
		show_hour(v3);
		show_ten(v2);
		show_minute(v1);
	
		delay_ms(1000);
	}	*/
  }
}