#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 20, 4); // set the LCD address to 0x27 for a 16 chars and 2 line display

uint8_t menuOptions = 3;

int8_t topOption = -1;
int8_t cursorPos = 0;

void DrawMenu(uint8_t topOpt){
  if(topOpt!=topOption){
    topOption = topOpt;
    for (uint8_t i = 0;i<4;i++){
      DrawOption(i,topOption);
    }
  }
  DrawCursor(cursorPos);
}
void DrawOption(uint8_t pos,uint8_t optionID){
  lcd.setCursor(1, pos);
  lcd.print("Option ");
  lcd.print(optionID);
}
void DrawCursor(uint8_t pos){
  if  (cursorPos!=pos){
    if  (cursorPos>-1){
      lcd.setCursor(0, cursorPos);
      lcd.print(' ');
    }
    if  (pos<4){
      cursorPos = pos;
      lcd.setCursor(0, pos);
      lcd.print('>');
    }else{
      cursorPos = -1;
    }
  }
  
}
int8_t pos = -1;

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


  lcd.init();                      // initialize the lcd
  // Print a message to the LCD.
  lcd.backlight();
  lcd.setCursor(1, 0);
  lcd.print("Hello, world!");
  lcd.setCursor(1, 1);
  lcd.print("Ywrobot Arduino!");
  lcd.setCursor(1, 2);
  lcd.print("Arduino");

  moveCursor(1);

  DrawMenu(0);

}

void moveCursor(int8_t p) {
  // put your main code here, to run repeatedly:
  if  (pos>-1){
    
  lcd.setCursor(0, pos);
  lcd.print(' ');
  }

  if  (p>-1 && p<4){
    pos=p;
      lcd.setCursor(0, pos);
      lcd.print('>');
    }
}

char cc;
void readSerial() {

  if (Serial.available() > 0) {

    char c = Serial.read();

    if (c != '\n') {

      if (Serial.read() == '\n') {
        cc = c;

       // keypad.triggerKeyPress(c);
      }
      
    }

    while (Serial.available() > 0) Serial.read();

  }


 // 
}

void onInput(char c) {

  if (c != 0) {
        Serial.print(F("Trigger Key '"));
        Serial.print(c);
        Serial.println(F("'"));

       // keypad.triggerKeyPress(c);
    }
  cc = 0;
  }

void loop() {
  // put your main code here, to run repeatedly:
    readSerial();

 
  
  delay(100);
}