#include <LiquidCrystal_I2C.h>

#define lenght 16.0
double percent=100.0;
unsigned char b;
unsigned int peace;

// Zeichenaufbau für eine vertikale Linie

byte p1[8] = {0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10};
byte p2[8] = {0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18};
byte p3[8] = {0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x1C};
byte p4[8] = {0x1E, 0x1E, 0x1E, 0x1E, 0x1E, 0x1E, 0x1E, 0x1E};
byte p5[8] = {0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F};

float targetTime = 5.0; // in Sekunden
float startTime; // in Millisekunden

LiquidCrystal_I2C	lcd(0x27,16,2); // 0x27 Adresse für das Display

void setup()   {
 
  lcd.init();  // Display initialisieren
  lcd.clear(); // Display löschen
  lcd.setBacklight(1);
  lcd.createChar(0, p1);
  lcd.createChar(1, p2);
  lcd.createChar(2, p3);
  lcd.createChar(3, p4);
  lcd.createChar(4, p5);
  
  lcd.clear();
  startTime = millis();
}

void loop()
{
  Wire.begin(21, 20);                      // "Umbiegen" der Anschlüsse für SDA und SCL auf Pin 21 und Pin 20 
  lcd.setCursor(0, 0);
  
  if (((millis()-startTime)/1000) < targetTime) {

  // calculate time until reached target

  percent = (millis() - startTime)/(1000*targetTime)*100.0;

  lcd.print("l\341uft..."); // Darstellung der Umlaute beachten
  if (int(targetTime - (millis()-startTime)/1000) > 9) {
    lcd.print(int(targetTime - (millis()-startTime)/1000));
    lcd.print("s");
  }
  else {
    lcd.print(" ");
    lcd.print(int(targetTime - (millis()-startTime)/1000));
    lcd.print("s");
  }
  
  lcd.setCursor(0,1);

  double a=lenght/100*percent;

 // drawing black rectangles on LCD

  if (a>=1) {

    for (int i=1;i<a;i++) {

      lcd.write(byte(4));

      b=i;
    }

    a=a-b;

  }

  peace=a*5;

// Zeichnen der Zeile

  switch (peace) {

  case 0:

    break;

  case 1:
    lcd.write(byte(0));

    break;

  case 2:
    lcd.write(byte(1));
    break;

  case 3:
    lcd.write(byte(2));
    break;

  case 4:
    lcd.write(byte(3));
    break;

  }

//Zeile löschen
  for (int i =0;i<(lenght-b);i++) {

    lcd.print(" ");
  }

  ;
  }
  else{
    lcd.print("Ziel erreicht.");
    lcd.setCursor(0, 1);
    for (int i=1;i<=16;i++) {

      lcd.write(byte(4));

      b=i;
    }
  }
}