WatchyWatchFace/src/WatchyRTC.cpp

#include "WatchyRTC.h"

WatchyRTC::WatchyRTC()
{
}

void WatchyRTC::init() {
  byte error;
  Wire.beginTransmission(RTC_PCF_ADDR);
  error = Wire.endTransmission();
}

void WatchyRTC::config(String datetime) { // String datetime format is YYYY:MM:DD:HH:MM:SS
  _PCFConfig(datetime);
}

void WatchyRTC::clearAlarm() {
  int nextAlarmMinute = 0;
  rtc_pcf.clearAlarm(); // resets the alarm flag in the RTC
  nextAlarmMinute = rtc_pcf.getMinute();
  nextAlarmMinute = (nextAlarmMinute == 59) ? 0 : (nextAlarmMinute + 1); // set alarm to trigger 1 minute from now
  rtc_pcf.setAlarm(nextAlarmMinute, 99, 99, 99);
}

void WatchyRTC::read(tmElements_t & tm, int offsetInSeconds) {
  rtc_pcf.getDate();
  tm.Year  = y2kYearToTm(rtc_pcf.getYear());
  tm.Month = rtc_pcf.getMonth();
  tm.Day   = rtc_pcf.getDay();
  tm.Wday = rtc_pcf.getWeekday() + 1; // TimeLib & DS3231 has Wday range of 1-7, but PCF8563 stores day of week in 0-6 range
  tm.Hour   = rtc_pcf.getHour();
  tm.Minute = rtc_pcf.getMinute();
  tm.Second = rtc_pcf.getSecond();

  int year = tm.Year;
  int month = tm.Month;
  int day = tm.Day;
  int hour = tm.Hour;
  int minute = tm.Minute;
  int second = tm.Second;

  // adjust for offset
  second += offsetInSeconds;
  if (second >= 60 || second < 0) {
    minute += second / 60;
    second = second % 60;
  }

  if (minute >= 60 || minute < 0) {
    hour += minute / 60;
    minute = minute % 60;
  }

  if (hour >= 24 || hour < 0) {
    day += hour / 24;
    hour = hour % 24;
  }

  bool leapYear = year % 4 == 0;
  if (leapYear) {
    if (month == 2 && day > 29) {
      month++;
      day = day % 29;
    }
  } else {
    if (month == 2 && day > 28) {
      month++;
      day = day % 28;
    }
  }

  if (month == 4 || month == 6 || month == 9 || month == 11) {
    if (day > 30) {
      month++;
      day = day % 30;
    }
  } else {
    if (day > 31) {
      month++;
      day = day % 31;
    }
  }

  if (month > 12 || month < 0) {
    year++;
    month = month % 12;
  }

  tm.Year = year;
  tm.Month = month;
  tm.Day = day;
  tm.Hour = hour;
  tm.Minute = minute;
  tm.Second = second;
}

void WatchyRTC::set(tmElements_t tm) {
  time_t t = makeTime(tm); // make and break to calculate tm.Wday
  breakTime(t, tm);
  // day, weekday, month, century(1=1900, 0=2000), year(0-99)
  rtc_pcf.setDate(tm.Day, tm.Wday - 1, tm.Month, 0, tmYearToY2k(tm.Year));
  rtc_pcf.setTime(tm.Hour, tm.Minute, tm.Second);
  clearAlarm();
}

void WatchyRTC::_PCFConfig(String datetime) { // String datetime is YYYY:MM:DD:HH:MM:SS
  if (datetime != "") {
    tmElements_t tm;
    tm.Year = CalendarYrToTm(_getValue(datetime, ':', 0).toInt()); // YYYY -
                                                                   // 1970
    tm.Month  = _getValue(datetime, ':', 1).toInt();
    tm.Day    = _getValue(datetime, ':', 2).toInt();
    tm.Hour   = _getValue(datetime, ':', 3).toInt();
    tm.Minute = _getValue(datetime, ':', 4).toInt();
    tm.Second = _getValue(datetime, ':', 5).toInt();
    time_t t  = makeTime(tm); // make and break to calculate tm.Wday
    breakTime(t, tm);
    // day, weekday, month, century(1=1900, 0=2000), year(0-99)
    rtc_pcf.setDate(
        tm.Day, tm.Wday - 1, tm.Month, 0,
        tmYearToY2k(tm.Year)); // TimeLib & DS3231 has Wday range of 1-7, but
                               // PCF8563 stores day of week in 0-6 range
    // hr, min, sec
    rtc_pcf.setTime(tm.Hour, tm.Minute, tm.Second);
  }

  // on POR event, PCF8563 sets month to 0, which will give an error since
  // months are 1-12
  clearAlarm();
}

String WatchyRTC::_getValue(String data, char separator, int index) {
  int found      = 0;
  int strIndex[] = {0, -1};
  int maxIndex   = data.length() - 1;

  for (int i = 0; i <= maxIndex && found <= index; i++) {
    if (data.charAt(i) == separator || i == maxIndex) {
      found++;
      strIndex[0] = strIndex[1] + 1;
      strIndex[1] = (i == maxIndex) ? i + 1 : i;
    }
  }

  return found > index ? data.substring(strIndex[0], strIndex[1]) : "";
}