DS3231 Alarms

// Date and time functions using a DS3231 RTC connected via I2C and Wire lib
#include "RTClib.h"

RTC_DS3231 rtc;

byte Year;
byte Month;
byte Date;
//byte DoW;
byte Hour;
byte Minute;
byte Second;
byte last_second;

unsigned long timer;

char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

void setup ()
{
    Serial.begin(115200);


    if (! rtc.begin())
    {
        Serial.println("Couldn't find RTC");
        Serial.flush();
        abort();
    }

    if (rtc.lostPower())
    {
        Serial.println("RTC lost power, let's set the time!");
        //rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));


    }
    rtc.setAlarm1 (DateTime (2020, 06, 23, 13, 01, 30), DS3231_A1_Day);
}

void GetDateStuff(byte& Year, byte& Month, byte& Day,
                  byte& Hour, byte& Minute, byte& Second)
{
    // Call this if you notice something coming in on
    // the serial port. The stuff coming in should be in
    // the order YYMMDDwHHMMSS, with an 'x' at the end.
    boolean GotString = false;
    char InChar;
    byte Temp1, Temp2;
    char InString[20];

    byte j = 0;
    while (!GotString)
    {
        if (Serial.available())
        {
            InChar = Serial.read();
            InString[j] = InChar;
            j += 1;
            if (InChar == 'x')
            {
                GotString = true;
            }
        }
    }
    Serial.println(InString);
    // Read Year first
    Temp1 = (byte)InString[0] - 48;
    Temp2 = (byte)InString[1] - 48;
    Year = Temp1 * 10 + Temp2;
    // now month
    Temp1 = (byte)InString[2] - 48;
    Temp2 = (byte)InString[3] - 48;
    Month = Temp1 * 10 + Temp2;
    // now date
    Temp1 = (byte)InString[4] - 48;
    Temp2 = (byte)InString[5] - 48;
    Day = Temp1 * 10 + Temp2;
    // now Day of Week
    //DoW = (byte)InString[6] - 48;
    // now Hour
    Temp1 = (byte)InString[6] - 48;
    Temp2 = (byte)InString[7] - 48;
    Hour = Temp1 * 10 + Temp2;
    // now Minute
    Temp1 = (byte)InString[8] - 48;
    Temp2 = (byte)InString[9] - 48;
    Minute = Temp1 * 10 + Temp2;
    // now Second
    Temp1 = (byte)InString[10] - 48;
    Temp2 = (byte)InString[11] - 48;
    Second = Temp1 * 10 + Temp2;
}

void Print_Time()
{
    DateTime now = rtc.now();

    if (now.day() < 10) Serial.print('0');
    Serial.print(now.day());
    Serial.print('/');
    if (now.month() < 10) Serial.print('0');
    Serial.print(now.month());
    Serial.print('/');
    Serial.print(now.year());

    Serial.print(" (");
    Serial.print(daysOfTheWeek[now.dayOfTheWeek()]);
    Serial.print(") ");
    if (now.hour() < 10) Serial.print('0');
    Serial.print(now.hour());
    Serial.print(':');
    if (now.minute() < 10) Serial.print('0');
    Serial.print(now.minute());
    Serial.print(':');
    if (now.second() < 10) Serial.print('0');
    Serial.print(now.second());
    Serial.println();
}

void loop ()
{
    if (Serial.available())
    {
        GetDateStuff(Year, Month, Date, Hour, Minute, Second);
        rtc.adjust(DateTime(Year, Month, Date, Hour, Minute, Second));
        Serial.flush();
    }


    if (rtc.alarmFired(1))
    {
        Serial.println("wake up!");
        rtc.clearAlarm(1);
    }

    DateTime now = rtc.now();
    if (now.second() != last_second)
    {
        last_second = now.second();
        Print_Time();
    }
}