#include <LiquidCrystal_I2C.h>

#define LED4  5

#define LED3 3


#define LCD_LINES 2
#define I2C_ADDR 0X27
#define LCD_COLUMNS 2

LiquidCrystal_I2C lcd(I2C_ADDR,LCD_COLUMNS,LCD_LINES);

#define koda1 111
#define koda2 333
#define koda3 444


int currTime = 0;
int del = 200;
bool m = LOW;
bool i = false;

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  Serial.begin(9600);
  Serial.println("vpisi stevilo");
  pinMode(LED3, OUTPUT);
  pinMode(LED3, OUTPUT);

}

void loop() {
  if(Serial.available()){
    char vpis[4];
    int steviloZnakovVpis = Serial.readBytes(vpis,3);
    if(steviloZnakovVpis == 3){
      vpis[3] = '\0';
      int stevilka = atoi(vpis);
      switch(stevilka){
        case koda1:
          lcd.clear();
          lcd.setCursor(0,1);
          lcd.print("LED3 vklop");
          digitalWrite(LED3, HIGH);
          break;

        case koda2:
          i = true;
          lcd.clear();
          lcd.setCursor(0,1);
          lcd.print("LED4 vklop");
          while(i == true){
            utripanje();
          }
          break;
       case koda3:
        for(int i = 0; i > 10; i++){
          utripanje();
        }
        break;
        
      }
    }
  }

}
void utripanje(){
  if(millis() - currTime > del){
    currTime = millis();
    digitalWrite(LED4,m);
    m = !m;
  }
}