/*
  ###  simplest ever Arduino UNO digital clock  ###

  This clock needs only a 1602 LCD 2X16 and 2 push buttons

  No Potentiometer for contrast, no resistors for pull-up or backlight !!!!

   The simplest clock ever made with a Arduino UNO

  Button Functions:

  - short stroke on one of the buttons put Backlight on for 30 s

  Time settings
  - Press on H increments the Hours
  - Press on M increments the Minutes and resets the seconds
*/


#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#define DS1307_I2C_ADDRESS 0x68

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

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

/*void setDS1307time(byte second, byte minute, byte hour, byte dayOfWeek, byte dayOfMonth, byte month, byte year) {
  // sets time and date data to DS1307
  Wire.beginTransmission(DS1307_I2C_ADDRESS);
  Wire.write(0); // set next input to start at the seconds register
  Wire.write(decToBcd(second)); // set seconds
  Wire.write(decToBcd(minute)); // set minutes
  Wire.write(decToBcd(hour)); // set hours
  Wire.write(decToBcd(dayOfWeek)); // set day of week (1=Sunday, 7=Saturday)
  Wire.write(decToBcd(dayOfMonth)); // set date (1 to 31)
  Wire.write(decToBcd(month)); // set month
  Wire.write(decToBcd(year)); // set year (0 to 99)
  Wire.endTransmission();
  }
*/

void readDS1307time(byte *second, byte *minute, byte *hour, byte *dayOfWeek, byte *dayOfMonth, byte *month, byte *year) {
  Wire.beginTransmission(DS1307_I2C_ADDRESS);
  Wire.write(0); // set DS1307 register pointer to 00h
  Wire.endTransmission();
  Wire.requestFrom(DS1307_I2C_ADDRESS, 7);
  // request seven bytes of data from DS1307 starting from register 00h
  *second = bcdToDec(Wire.read() & 0x7f);
  *minute = bcdToDec(Wire.read());
  *hour = bcdToDec(Wire.read() & 0x3f);
  *dayOfWeek = bcdToDec(Wire.read());
  *dayOfMonth = bcdToDec(Wire.read());
  *month = bcdToDec(Wire.read());
  *year = bcdToDec(Wire.read());
  *second = sec;
}

void displayTime() {
  byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
  // retrieve data from DS1307
  readDS1307time(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year);
  // send it to the serial monitor
  Serial.print(hour, DEC);
  // convert the byte variable to a decimal number when displayed
  Serial.print(":");
  if (minute < 10) {
    Serial.print("0");
  }
  Serial.print(minute, DEC);
  Serial.print(":");
  if (second < 10) {
    Serial.print("0");
  }
  Serial.print(second, DEC);
  Serial.print(" ");
  Serial.print(dayOfMonth, DEC);
  Serial.print(".");
  Serial.print(month, DEC);
  Serial.print(".20");
  Serial.print(year, DEC);
  Serial.print(" ");
  switch (dayOfWeek) {
    case 1:
      Serial.println("Neděle");
      break;
    case 2:
      Serial.println("Pondělí");
      break;
    case 3:
      Serial.println("Úterý");
      break;
    case 4:
      Serial.println("Středa");
      break;
    case 5:
      Serial.println("Čtvrtek");
      break;
    case 6:
      Serial.println("Pátek");
      break;
    case 7:
      Serial.println("Sobota");
      break;
  }
}

// clear the terminal screen and send the cursor home
void clearAndHome() {
  Serial.write(27);
  Serial.print("[2J"); // clear screen
  Serial.write(27);    // ESC
  Serial.print("[H");  // cursor to home
}

// This defines the LCD wiring to the DIGITALpins
LiquidCrystal_I2C lcd(0x27, 20, 2);

// Digital LCD Constrast setting
int cs = 9; // pin 9 for contrast PWM
const int contrast = 20;// default contrast

// initial Time display is 12:59:45 PM
int h = 23;
int m = 59;
int s = 45;
int flag = 1; //PM

// Time Set Buttons
int button1;
int button2;

// Pins definition for Time Set Buttons
int hs = 0; // pin 0 for Hours Setting
int ms = 1; // pin 1 for Minutes Setting

// Backlight Time Out
const int Time_light = 150;
int bl_TO = Time_light; // Backlight Time-Out
int bl = 10; // Backlight pin
const int backlight = 40; // no more then 7mA !!!

// For accurate Time reading, use Arduino Real Time Clock and not just delay()
static uint32_t last_time, now = 0; // RTC

byte aa [8] = {
  B00001,
  B00010,
  B00000,
  B01110,
  B00001,
  B01111,
  B10001,
  B01111,
};

byte cz [8] = {
  B01010,
  B00100,
  B00000,
  B01110,
  B10000,
  B10000,
  B10001,
  B01110,  
};

void setup() {
  Serial.begin(115200);
  Wire.begin();
  // set the initial time here:
  // DS1307 seconds, minutes, hours, day, date, month, year
  // setDS1307time(30,42,21,4,26,11,14);

  lcd.begin(16, 2);
  lcd.createChar(0, aa);
  lcd.createChar(1, cz);
  pinMode(hs, INPUT_PULLUP); // avoid external Pullup resistors for Button 1
  pinMode(ms, INPUT_PULLUP); // and Button 2
  analogWrite(cs, contrast); // Adjust Contrast VO
  analogWrite(bl, backlight); // Turn on Backlight
  now = millis(); // read RTC initial value
}

void loop() {
  if (second != s) {
    clearAndHome();
    displayTime();
  }
}

/* void loop() {

  lcd.begin(16, 2); // every second
  // Update LCD Display
  // Print TIME in Hour, Min, Sec + AM/PM
  lcd.setCursor(4, 0);
  //lcd.print("Time ");
  if (h < 10)lcd.print("0"); // always 2 digits
  lcd.print(h);
  lcd.print(":");
  if (m < 10)lcd.print("0");
  lcd.print(m);
  lcd.print(":");
  if (s < 10)lcd.print("0");
  lcd.print(s);

  //if(flag==0) lcd.print(" AM");
  //if(flag==1) lcd.print(" PM");

  clearAndHome();
  displayTime(); // display the real-time clock data on the Serial Monitor,

  if ((h >= 4) && (h < 9))
  {
    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(6, 1);
    lcd.print("R");
    lcd.write(byte(0));
    lcd.print ("no");
  }
  if ((h >= 9) && (h < 12))
  {
    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(3, 1);
    lcd.print("Dopoledne");
  }
  if ((h >= 12) && (h < 18))
  {
    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(3, 1);
    lcd.print("Odpoledne");
  }
  if ((h >= 18) && (h < 22))
  {
    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(5, 1);
    lcd.print("Ve");
    lcd.write(byte(1));
    lcd.print ("er");
  }
  if ((h < 4) | (h >= 22))
  {
    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(6, 1);
    lcd.print("Noc");
  }

  // improved replacement of delay(1000)
  // Much better accuracy, no more dependant of loop execution time

  for ( int i = 0 ; i < 5 ; i++) // make 5 time 200ms loop, for faster Button response
  {

    while ((now - last_time) < 200) //delay200ms
    {
      now = millis();
    }
    // inner 200ms loop
    last_time = now; // prepare for next loop

    // read Setting Buttons
    button1 = digitalRead(hs); // Read Buttons
    button2 = digitalRead(ms);

    //Backlight time out
    bl_TO--;
    if (bl_TO == 0)
    {
      analogWrite(bl, 0); // Backlight OFF
      bl_TO++;
    }

    // Hit any to activate Backlight
    if (  ((button1 == 0) | (button2 == 0)) & (bl_TO == 1)  )
    {
      bl_TO = Time_light;
      analogWrite(bl, backlight);
      // wait until Button released
      while ((button1 == 0) | (button2 == 0))
      {
        button1 = digitalRead(hs); // Read Buttons
        button2 = digitalRead(ms);
      }
    }
    else
      // Process Button 1 or Button 2 when hit while Backlight on
    {
      if (button1 == 0) {
        h = h + 1;
        bl_TO = Time_light;
        analogWrite(bl, backlight);
      }

      if (button2 == 0) {
        s = 0;
        m = m + 1;
        bl_TO = Time_light;
        analogWrite(bl, backlight);
      }

      // ---- manage seconds, minutes, hours am/pm overflow ----//
      if (s == 60) {
        s = 0;
        m = m + 1;
      }
      if (m == 60)
      {
        m = 0;
        h = h + 1;
      }
      if (h == 24)
      {
        h = 0;
        flag = flag + 1;
        if (flag == 2)flag = 0;
      }


      if ((button1 == 0) | (button2 == 0)) // Update display if time set button pressed
      {
        // Update LCD Display
        // Print TIME in Hour, Min, Sec + AM/PM
        lcd.setCursor(4, 0);
        //lcd.print("Time ");
        if (h < 10)lcd.print("0"); // always 2 digits
        lcd.print(h);
        lcd.print(":");
        if (m < 10)lcd.print("0");
        lcd.print(m);
        lcd.print(":");
        if (s < 10)lcd.print("0");
        lcd.print(s);

        // if(flag==0) lcd.print(" AM");
        // if(flag==1) lcd.print(" PM");

        lcd.setCursor(0, 1); // for Line 2
        lcd.print("Alzheimer hodiny");
      }


    } // end if else
  }// end for



  // outer 1000ms loop

  s = s + 1; //increment sec. counting


  // ---- manage seconds, minutes, hours am/pm overflow ----
  if (s == 60) {
    s = 0;
    m = m + 1;
  }
  if (m == 60)
  {
    m = 0;
    h = h + 1;
  }
  if (h == 24)
  {
    h = 0;
    flag = flag + 1;
    if (flag == 2)flag = 0;
  }
  // Loop end
*/