//Adapted from https://www.hackster.io/embeddedlab786/real-time-clock-with-timer-60fdd4
//by Tina Keil (a4r.eu), 2023

#include <Wire.h>
#include <RTClib.h>
#include <EEPROM.h>
#include <DHT.h>
#include <LiquidCrystal.h>

//define pin allocations
#define relay     8
#define DHTPIN    12
#define buzzer    13

//buttons
#define bt_clock  A0
#define bt_up     A1
#define bt_down   A2
#define bt_timer  A3

#define DS1307_ADDRESS 0x68
#define DHTTYPE   DHT22

bool debug = true;
byte zero = 0x00; //workaround for issue #527

//pins to lcd
LiquidCrystal lcd(2, 3, 4, 5, 6, 7); 

//Init RTC Clock
RTC_DS1307 RTC; 

// Initialize DHT sensor.
DHT dht(DHTPIN, DHTTYPE);

int hh = 0, mm = 0, ss = 0, set_day = 0, dd = 0, bb = 0, yy = 0;
int stop = 0, mode = 0, flag = 0;
String Day = "";

char daysOfTheWeek[7][12] = {"So", "Mo", "Di", "Mi", "Do", "Fr", "Sa"};

int StartHH = 0, StartMM = 0, FinishHH = 0, FinishMM = 0;
int setMode = 0, setAlarm = 0, alarmMode = 1;

//Init Timers (1-4)
int Start1HH, Start1MM, Finish1HH, Finish1MM;
int Start2HH, Start2MM, Finish2HH, Finish2MM;
int Start3HH, Start3MM, Finish3HH, Finish3MM;
int Start4HH, Start4MM, Finish4HH, Finish4MM;

int timer1, timer2, timer3, timer4;

void setup() {
  
  if (debug) {
    Serial.begin(57600);
  }

  RTC.begin(); //Init Real Time Clock
  dht.begin(); //Init temperature and humidity sensor

  pinMode(bt_clock, INPUT_PULLUP);
  pinMode(bt_up,    INPUT_PULLUP);
  pinMode(bt_down,  INPUT_PULLUP);
  pinMode(bt_timer, INPUT_PULLUP);

  pinMode(relay, OUTPUT);
  digitalWrite(relay, HIGH);

  pinMode(buzzer, OUTPUT);

  lcd.begin(16, 2); // 16 columns, 2 rows
  lcd.setCursor(0,0); 
  lcd.print("* Zeitschalter *");
  lcd.setCursor(0,1);
  lcd.print("  mit 4 Zeiten  ");
  delay(2000);
  lcd.clear();

  stop = EEPROM.read(50);  
  if (stop == 0) {  
  } else {
    mode = 1; WriteEeprom (); delay (20);
    mode = 2; WriteEeprom (); delay (20);
    mode = 3; WriteEeprom (); delay (20);
    mode = 4; WriteEeprom (); delay (20);
    mode = 0;
  }
  EEPROM.write(50,0); 
  ReadEeprom();
}

void loop() { 

  DateTime now = RTC.now(); // Clock call
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  if (debug)  {
    //mode
    //Values 1-4 defines which timer is selected. 
    //Value 5 defines that timers are written to Eprom.

    //setAlarm changes when button 4 is pressed. First it determines the state of the timers.
    //That means if they are activatd(+) or detactived. Once the state of all timers have been
    //defined it determines the value of setAlarm defines the start/stop times of each timer.
    //E.g. 1 = hours ON selected, 2 = minutes ON selected, 3 = hours OFF selected, 
    //4 = minutes OFF selected. 

    //setMode (1-7) changes when button 1 is pressed. It defines what is being set. 
    //1 = hour, 2 = minute, 3 = seconds, 4 = Weekeday, 5 = day, 6 = month, 7 = year
    
    //alarmMode equals 1 when a timer has been set and is active. 0 means that no timer is active,
    //which is the case when 

    Serial.print("mode      = "); Serial.println(mode);
    Serial.print("setMode   = "); Serial.println(setMode);
    Serial.print("setAlarm  = "); Serial.println(setAlarm);
    Serial.print("alarmMode = "); Serial.println(alarmMode);
    Serial.println("-------");
  } 

  if (setMode == 0) {
    hh = now.hour(),DEC;
    mm = now.minute(),DEC;
    ss = now.second(),DEC;
    dd = now.day(),DEC;
    bb = now.month(),DEC;
    yy = now.year(),DEC;
    Day = daysOfTheWeek[now.dayOfTheWeek()];
  }

  if (setAlarm == 0) {
    lcd.setCursor(0,0); 

    //hours
    lcd.print((hh/10)%10);
    lcd.print(hh % 10); 
    lcd.print(":");

    //minutes
    lcd.print((mm/10)%10);
    lcd.print(mm % 10);
    lcd.print(":");

    //seconds
    lcd.print((ss/10)%10);
    lcd.print(ss % 10); 
    lcd.print("  ");

    //temperature / humidity (alterante every minute)
    if (mm % 2 != 0) {
      lcd.print(temp, 0);
      lcd.write(223); 
      lcd.print("C ");
    } else {
      lcd.print(hum, 0);
      lcd.write("%RH");
    }

    //day of week and date
    lcd.setCursor(0,1);
    lcd.print(Day);
    lcd.print(". ");

    lcd.print((dd/10)%10);
    lcd.print(dd % 10); 
    lcd.print(".");

    lcd.print((bb/10)%10);
    lcd.print(bb % 10);
    lcd.print("."); 

    lcd.print((yy/1000)%10);
    lcd.print((yy/100)%10);
    lcd.print((yy/10)%10);
    lcd.print(yy % 10);
  }

  setupClock();
  setTimer();
  delay(100);
  blinking();

  //Timer1 ON
  if (timer1 == 1 && alarmMode == 1 && hh == Start1HH && mm == Start1MM) {
    digitalWrite(relay, LOW);
  }
  //Timer1 OFF
  if (timer1 == 1 && alarmMode == 1 && hh == Finish1HH && mm == Finish1MM) {
    digitalWrite(relay, HIGH);
  }

  //Timer2 ON
  if (timer2 == 1 && alarmMode == 1 && hh == Start2HH && mm == Start2MM) {
    digitalWrite(relay, LOW);
  }
  //Timer2 OFF
  if (timer2 == 1 && alarmMode == 1 && hh == Finish2HH && mm == Finish2MM) {
    digitalWrite(relay, HIGH);
  }

  //Timer3 ON
  if (timer3 == 1 && alarmMode == 1 && hh == Start3HH && mm == Start3MM) {
    digitalWrite(relay, LOW);
  }
  //Timer3 OFF
  if (timer3 == 1 && alarmMode == 1 && hh == Finish3HH && mm == Finish3MM) {
    digitalWrite(relay, HIGH);
  }

  //Timer4 ON
  if (timer4 == 1 && alarmMode == 1 && hh == Start4HH && mm == Start4MM) {
    digitalWrite(relay, LOW);
  }
  //Timer4 OFF
  if (timer4 == 1 && alarmMode == 1 && hh == Finish4HH && mm == Finish4MM) {
    digitalWrite(relay, HIGH);
  }

  delay (100);
  digitalWrite(buzzer, LOW);
}

byte setDOW (byte weekDay) {
  Wire.beginTransmission(DS1307_ADDRESS);
  Wire.write(zero); //stop Oscillator
  Wire.write(decToBcd(weekDay));
  Wire.write(zero); //start 
  Wire.endTransmission();
}

byte decToBcd(byte val){
  //Convert normal decimal numbers to binary coded decimal
  return ((val/10*16) + (val%10));
}

void blinking () {
  //BLINKING SCREEN

  //Set Clock
  if (setAlarm < 2 && setMode == 1) {
    lcd.setCursor(0,0);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 2) {
    lcd.setCursor(3,0);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 3) {
    lcd.setCursor(6,0);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 4) {
    lcd.setCursor(1,1);
    lcd.print("   ");
  }
  if (setAlarm < 2 && setMode == 5) {
    lcd.setCursor(5,1);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 6) {
    lcd.setCursor(8,1);
    lcd.print("  ");
  }
  if (setAlarm < 2 && setMode == 7) {
    lcd.setCursor(11,1);
    lcd.print("    ");
  }

  //Set Timer
  if (setMode == 0 && setAlarm == 1 && mode == 0){
    lcd.setCursor(2,1);
    lcd.print("  ");
  }
  if (setMode == 0 && setAlarm == 2 && mode == 0){
    lcd.setCursor(6,1);
    lcd.print("  ");
  }
  if (setMode == 0 && setAlarm == 3 && mode == 0){
    lcd.setCursor(10,1);
    lcd.print("  ");
  }
  if (setMode == 0 && setAlarm == 4 && mode == 0){
    lcd.setCursor(13,1);
    lcd.print("  ");
  }

  if (setMode == 0 && setAlarm == 1 && mode > 0){
    lcd.setCursor(11,0);
    lcd.print("  ");
  }
  if (setMode == 0 && setAlarm == 2 && mode > 0){
    lcd.setCursor(14,0);
    lcd.print("  ");
  }
  if (setMode == 0 && setAlarm == 3 && mode > 0){
    lcd.setCursor(11,1);
    lcd.print("  ");
  }
  if (setMode == 0 && setAlarm == 4 && mode > 0){
    lcd.setCursor(14,1);
    lcd.print("  ");
  }
}

//Set Clock, Date, Alarm/Timer
void setupClock(void) {

  if (debug) {
      Serial.println("***");
      Serial.print("mode = ");
      Serial.println(mode);
      Serial.print("bt_clock = ");
      Serial.println(digitalRead(bt_clock));
      Serial.print("bt_timer = ");
      Serial.println(digitalRead(bt_timer));
      Serial.println("***");
  }

  if (setMode == 8) {
    lcd.setCursor(0,0);
    lcd.print ("Set Time Finish ");
    lcd.setCursor (0,1);
    lcd.print ("Set Date Finish ");
    delay(1000);
    RTC.adjust(DateTime(yy, bb, dd, hh, mm, ss));
    lcd.clear();
    setMode = 0;
  }
    
  if (setAlarm > 0){
    alarmMode = 0;
  }
  
  //when the clock is saved
  if (digitalRead(bt_clock) == 0 && flag == 0) {
    flag = 1;
    if (setAlarm > 0) {
      WriteEeprom(); 
      setAlarm = 1;
      mode = 5;
    } else {
      setMode = setMode + 1;
    }
    if (debug) {
      Serial.println("-x-x Clock x-x");
      Serial.print("flag = ");
      Serial.println(flag);
      Serial.print("bt_clock = ");
      Serial.println(digitalRead(bt_clock));
      Serial.print("buzzer = ");
      Serial.println(buzzer);
      Serial.println("-x-x-x-x");
    }
    tone(13,500,100); //play tone
  }
  
  //when the Timer is saved
  if (digitalRead(bt_timer) == 0 && flag == 0){
    flag = 1;
    if (setMode > 0) {
      setMode = 8;
    } else {
      setAlarm = setAlarm + 1;
      if (setAlarm > 4) {
        setAlarm = 1; 
        WriteEeprom();
        mode = mode + 1;
        ReadEeprom();
      }
    } 
    lcd.clear();
    if (debug) {
      Serial.println("-x-x Timer x-x");
      Serial.print("flag = ");
      Serial.println(flag);
      Serial.print("bt_timer = ");
      Serial.println(digitalRead(bt_timer));
      Serial.print("buzzer = ");
      Serial.println(buzzer);
      Serial.println("-x-x-x-x");
    }  
    tone(13,500,100); //play tone
  } 
 
  if (setAlarm == 1 && mode == 5) {
    lcd.setCursor(0,0);
    lcd.print (" Timer Setup OK ");
    lcd.setCursor(0,1);
    lcd.print (" EEPROM written ");
    delay(2000); 
    lcd.clear();
    setAlarm = 0;
    mode = 0;
    alarmMode = 1;
  }

  if (digitalRead(bt_clock) == 1 && digitalRead(bt_timer) == 1) {
    flag = 0;
  }
  
  if (digitalRead(bt_up) == 0) {                       
    if (setAlarm < 2 && setMode == 1) hh = hh + 1; 
    if (setAlarm < 2 && setMode == 2) mm = mm + 1;
    if (setAlarm < 2 && setMode == 3) ss = ss + 1;
    if (setAlarm < 2 && setMode == 4) set_day = set_day + 1;
    if (setAlarm < 2 && setMode == 5) dd = dd + 1;
    if (setAlarm < 2 && setMode == 6) bb = bb + 1;
    if (setAlarm < 2 && setMode == 7) yy = yy + 1;
              
    //Timer
    if (mode == 0 && setMode == 0 && setAlarm == 1) timer1 = 1;
    if (mode == 0 && setMode == 0 && setAlarm == 2) timer2 = 1;
    if (mode == 0 && setMode == 0 && setAlarm == 3) timer3 = 1;
    if (mode == 0 && setMode == 0 && setAlarm == 4) timer4 = 1;
              
    if (mode > 0 && setMode == 0 && setAlarm == 1) StartHH = StartHH + 1;
    if (mode > 0 && setMode == 0 && setAlarm == 2) StartMM = StartMM + 1;
    if (mode > 0 && setMode == 0 && setAlarm == 3) FinishHH = FinishHH + 1;
    if (mode > 0 && setMode == 0 && setAlarm == 4) FinishMM = FinishMM + 1;

    if (hh > 23) hh = 0;
    if (mm > 59) mm = 0;
    if (ss > 59) ss = 0;
    if (set_day > 7) set_day = 0;
    if (dd > 31) dd = 0;
    if (bb > 12) bb = 0;
    if (yy > 2040) yy = 2020;
    
    if (StartHH > 23)  StartHH = 0;
    if (StartMM > 59)  StartMM = 0;
    if (FinishHH > 23) FinishHH = 0;
    if (FinishMM > 59) FinishMM = 0;

    setDOW(set_day);
    digitalWrite(relay, HIGH); //reset relay
    tone(13,500,50); //play tone
  }        

  if (digitalRead(bt_down) == 0) {                                      
    if (setAlarm < 2 && setMode == 1 )hh = hh - 1; 
    if (setAlarm < 2 && setMode == 2) mm = mm - 1;
    if (setAlarm < 2 && setMode == 3) ss = ss - 1;
    if (setAlarm < 2 && setMode == 4) set_day = set_day - 1;
    if (setAlarm < 2 && setMode == 5) dd = dd - 1;
    if (setAlarm < 2 && setMode == 6) bb = bb - 1;
    if (setAlarm < 2 && setMode == 7) yy = yy - 1;
    
    //Timer
    if (mode == 0 && setMode == 0 && setAlarm == 1) timer1 = 0;
    if (mode == 0 && setMode == 0 && setAlarm == 2) timer2 = 0;
    if (mode == 0 && setMode == 0 && setAlarm == 3) timer3 = 0;
    if (mode == 0 && setMode == 0 && setAlarm == 4) timer4 = 0;
              
    if (mode > 0 && setMode == 0 && setAlarm == 1) StartHH = StartHH - 1;
    if (mode > 0 && setMode == 0 && setAlarm == 2) StartMM = StartMM - 1;
    if (mode > 0 && setMode == 0 && setAlarm == 3) FinishHH = FinishHH - 1;
    if (mode > 0 && setMode == 0 && setAlarm == 4) FinishMM = FinishMM - 1;

    if (hh < 0) hh = 23;
    if (mm < 0) mm = 59;
    if (ss < 0) ss = 59;
    if (set_day < 0) set_day = 7;
    if (dd < 0) dd = 31;
    if (bb < 0) bb = 12;
    if (yy < 0) yy = 2040;

    if (StartHH < 0) StartHH   = 23;
    if (StartMM < 0) StartMM   = 59;
    if (FinishHH < 0) FinishHH = 23;
    if (FinishMM < 0) FinishMM = 59;

    setDOW(set_day);
    digitalWrite(relay, HIGH); //reset relay
    tone(13,500,50); //play tone 
  }
}

void setTimer () {
  //Timer
  if (setMode == 0 && setAlarm > 0 && mode > 0){
    lcd.setCursor(0,0);
    lcd.print("Timer");
    lcd.print(mode);
    lcd.print(" An :");
    lcd.setCursor(11,0);
    lcd.print((StartHH/10)%10);
    lcd.print(StartHH % 10);
    lcd.print(":");
    lcd.print((StartMM/10)%10);
    lcd.print(StartMM % 10);

    lcd.setCursor(0,1);
    lcd.print("Timer");
    lcd.print(mode);
    lcd.print(" Aus:");
    lcd.setCursor (11,1);
    lcd.print((FinishHH/10)%10);
    lcd.print(FinishHH % 10);
    lcd.print(":");
    lcd.print((FinishMM/10)%10);
    lcd.print(FinishMM % 10);
  }

  if (setMode == 0 && setAlarm > 0 && mode == 0){
    lcd.setCursor(0,0);
    lcd.print(" T1  T2  T3  T4 ");
    lcd.setCursor (0,1);

    if (timer1 == 1) {
      lcd.print(" AN");
    } else {
      lcd.print(" AUS");
    }
    
    if (timer2 == 1) {
      lcd.print("  AN");
    } else {
      lcd.print(" AUS");
    }
    
    if (timer3 == 1) {
      lcd.print("  AN");
    } else {
      lcd.print(" AUS");
    }
    
    if (timer4 == 1) {
      lcd.print("  AN");
    } else {
      lcd.print(" AUS ");
    }
  }
}

void ReadEeprom() {
  Start1HH  = EEPROM.read(11);
  Start1MM  = EEPROM.read(12);
  Finish1HH = EEPROM.read(13);
  Finish1MM = EEPROM.read(14);

  Start2HH  = EEPROM.read(21);
  Start2MM  = EEPROM.read(22);
  Finish2HH = EEPROM.read(23);
  Finish2MM = EEPROM.read(24);

  Start3HH  = EEPROM.read(31);
  Start3MM  = EEPROM.read(32);
  Finish3HH = EEPROM.read(33);
  Finish3MM = EEPROM.read(34);

  Start4HH  = EEPROM.read(41);
  Start4MM  = EEPROM.read(42);
  Finish4HH = EEPROM.read(43);
  Finish4MM = EEPROM.read(44);

  if (mode == 1) {
    StartHH = Start1HH, StartMM = Start1MM;
    FinishHH = Finish1HH, FinishMM = Finish1MM;
  }
  if (mode == 2) {
    StartHH = Start2HH, StartMM = Start2MM; 
    FinishHH = Finish2HH, FinishMM = Finish2MM;
  }
  if (mode == 3) {
    StartHH = Start3HH, StartMM = Start3MM; 
    FinishHH = Finish3HH, FinishMM = Finish3MM;
  }
  if (mode == 4) {
    StartHH = Start4HH, StartMM = Start4MM; 
    FinishHH = Finish4HH, FinishMM = Finish4MM;
  }

  timer1 = EEPROM.read(1);
  timer2 = EEPROM.read(2);
  timer3 = EEPROM.read(3);
  timer4 = EEPROM.read(4);
}

void WriteEeprom() {
  if (mode == 1) {
    EEPROM.write(11,StartHH);
    EEPROM.write(12,StartMM);
    EEPROM.write(13,FinishHH);
    EEPROM.write(14,FinishMM);
  }
  if (mode == 2) {
    EEPROM.write(21,StartHH);
    EEPROM.write(22,StartMM);
    EEPROM.write(23,FinishHH);
    EEPROM.write(24,FinishMM);
  }
  if (mode == 3) {
    EEPROM.write(31,StartHH);
    EEPROM.write(32,StartMM);
    EEPROM.write(33,FinishHH);
    EEPROM.write(34,FinishMM);
  }
  if (mode == 4) {
    EEPROM.write(41,StartHH);
    EEPROM.write(42,StartMM);
    EEPROM.write(43,FinishHH);
    EEPROM.write(44,FinishMM);
  }

  EEPROM.write(1, timer1);
  EEPROM.write(2, timer2);
  EEPROM.write(3, timer3);
  EEPROM.write(4 ,timer4);
}