#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

unsigned long timestamp; 

int screenWidth = 16;
int stringStart,stringEndRepeat, stringEnd = 0;
int scrollCursor = screenWidth;
int scrollCursorRepeat = screenWidth;
unsigned long scroll_timestamp = millis();

unsigned long blink_timestamp = millis();
volatile boolean blink_indicator = true;


void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.clear();
}
void loop() {
  scrollTextDisplay("Press The Start Button", 0, 5, 200);
  BlinkText("PressStart", 3, 1, 500);
  
}
void scrollTextDisplay(String Your_Text_Here, int Top_Or_Bottom, int Text_Spacing, int Scroll_Text_Delay) {
  String line2 = " " + Your_Text_Here + " "; 
  if ((millis() - scroll_timestamp) > Scroll_Text_Delay){
    if (stringStart == 0 && scrollCursor > 0 && line2.length()<screenWidth){
      scrollCursor--;
      stringEnd++;
      lcd.setCursor(scrollCursor, Top_Or_Bottom); 
      lcd.print(line2.substring(stringStart,stringEnd));
      Serial.println(stringEnd);
    }
    if (stringEnd >= screenWidth && line2.length() < screenWidth){
      stringStart++;
      stringEnd++;
      scrollCursor = 0;
      lcd.setCursor(scrollCursor, Top_Or_Bottom); 
      lcd.print(line2.substring(stringStart,stringEnd)); 
      Serial.println(line2.length());
      Serial.println(stringEnd);
      if (stringEnd == (15 + line2.length())){
        stringStart = 0;
        stringEnd = 0;
        scrollCursor=screenWidth;
      }
    }
    if(stringStart == 0 && scrollCursor > 0 && line2.length()>=screenWidth){
      lcd.setCursor(scrollCursor, Top_Or_Bottom); 
      lcd.print(line2.substring(stringStart,stringEnd)); 
      scrollCursor--;
      stringEnd++;
    }
    if (stringEnd >= screenWidth && stringEnd < (line2.length() + Text_Spacing) && line2.length()>=screenWidth){
      lcd.setCursor(scrollCursor, Top_Or_Bottom); 
      lcd.print(line2.substring(stringStart,stringEnd)); 
      stringStart++;
      stringEnd++;
      scrollCursor = 0;
      Serial.println(line2.length());
      Serial.println(stringEnd);
    }
    if (stringEnd >= (line2.length()) && line2.length()>=screenWidth){
    lcd.setCursor(scrollCursor, Top_Or_Bottom); 
    lcd.print(line2.substring(stringStart,stringEnd));
    lcd.setCursor((scrollCursorRepeat),Top_Or_Bottom);
    lcd.print(line2.substring(0, stringEndRepeat));
    stringEndRepeat++;
    scrollCursorRepeat--;
    stringStart++;
    stringEnd++;
    }
    if (stringEndRepeat >= screenWidth && line2.length()>=screenWidth){
      stringStart = 0;
      scrollCursor = 0;
      stringEnd = screenWidth;
      scrollCursorRepeat = screenWidth;
      stringEndRepeat = 0;
    }
    scroll_timestamp = millis();
  }
}

void BlinkText (String Your_Text_Here, int Position_01to16, int Top_Or_Bottom, int Blink_Delay){
  if ((millis() - blink_timestamp) >= Blink_Delay){  
    if (blink_indicator == true){
      lcd.setCursor(Position_01to16, Top_Or_Bottom);
      lcd.print(Your_Text_Here);
      Serial.println(blink_indicator);
    }
    if (blink_indicator == false){
      lcd.setCursor(0, Top_Or_Bottom);
      lcd.print("                ");
    }
  blink_indicator = !blink_indicator;
  blink_timestamp = millis();
  }
}