package stamp.peripheral.io;

import stamp.core.*;
import stamp.peripheral.io.I2C;

/**
 * I2C Real Time Clock.
 *
 * This class manipulates a Dallas DS1307 RTC clock IC
 *
 * DS1307(I2C) constructor method I2C is pointer to an I2C object
 * setclock(hour,min,sec) sets the time
 * setdate(days,month,year) sets the date, year does not inc century
 * setday(day) sets day of the week 1=sun, 2=mon, etc
 * getreg(reg) get the contents of DS1307 reg see data sheet for IC
 * gettime() returns current time in hh:mm:ss format
 * getdate() returns date in dd/mm/yyyy format
 * getday() returns day of the week in Sun, Mon etc format

 * @version 1.1 22 August 2004
 * @author Steven Tron
 */

public class DS1307 {

  final static int WRAddr = 0xD0;
  final static int RDAddr = 0xD1;
  final static int Sec = 0x0;
  final static int Min = 0x1;
  final static int Hour = 0x2;
  final static int Day = 0x3;
  final static int Days = 0x4;
  final static int Month = 0x5;
  final static int Year = 0x6;
  final static int Nak = 0x1;

  protected static I2C ioBus;
  protected static StringBuffer rtcval = new StringBuffer(7);

  public DS1307(I2C bus){
    this.ioBus = bus;
  }

  private static int int2bcd(int val){
    return ((val/10)*16)+(val%10);
  }

  private static int bcd2int(int val){
    return ((val/16)*10)+(val%16);
  }

  private static void setreg(int reg) {
    ioBus.start();
    ioBus.write(WRAddr);
    ioBus.write(reg);
    }

  public static void setclock(int hours, int mins, int secs) {
    setreg(Sec);
    ioBus.write(int2bcd(secs));
    ioBus.write(int2bcd(mins));
    ioBus.write(int2bcd(hours));
    ioBus.stop();
    }

  public static void setday(int day) {
    setreg(Day);
    ioBus.write(day);
    ioBus.stop();
    }

  public static void setdate(int days, int month, int year) {
    setreg(Days);
    ioBus.write(int2bcd(days));
    ioBus.write(int2bcd(month));
    ioBus.write(int2bcd(year));
    ioBus.stop();
    }

   public static int getreg(int reg) {
    int val = 0;
    setreg(reg);
    ioBus.start();
    ioBus.write(RDAddr);
    val = ioBus.read(Nak);
    ioBus.stop();
    return bcd2int(val);
    }

   public static String getdate() {
   rtcval.clear();
   rtcval.append(getreg(Days));
   rtcval.append('/');
   rtcval.append(getreg(Month));
   rtcval.append('/');
   if ((getreg(Year)/10)==0) {
    rtcval.append(200);
    rtcval.append(getreg(Year));
    }
   else {
    rtcval.append(20);
    rtcval.append(getreg(Year));
    }
   return rtcval.toString();
   }

   public static String gettime() {
   rtcval.clear();
   rtcval.append(getreg(Hour));
   rtcval.append(':');
   if ((getreg(Min)/10)==0) {
    rtcval.append(0);
    rtcval.append(getreg(Min));
    }
   else {
    rtcval.append(getreg(Min));
    }
   rtcval.append(':');
   if ((getreg(Sec)/10)==0) {
    rtcval.append(0);
    rtcval.append(getreg(Sec));
    }
   else {
    rtcval.append(getreg(Sec));
    }
   return rtcval.toString();
   }

   public static String getday() {
   rtcval.clear();
   switch (getreg(Day)) {
    case 1:
          rtcval.append("Sun");
          break;

    case 2:
          rtcval.append("Mon");
          break;
    case 3:
          rtcval.append("Tue");
          break;
    case 4:
          rtcval.append("Wed");
          break;
    case 5:
          rtcval.append("Thur");
          break;
    case 6:
          rtcval.append("Fri");
          break;
    case 7:
          rtcval.append("Sat");
          break;
    }
   return rtcval.toString();
   }
} 