#include <LiquidCrystal.h>
LiquidCrystal lcd(12,11,5,4,3,2);
int laser;
int laser_step;
unsigned int timerstart;
unsigned int timerinterval;
unsigned int currenttime;

void setup() {
  // put your setup code here, to run once:
  lcd.begin(16,2);
  laser=0;
  laser_step=0;
  lcd.setCursor(0,0);
  lcd.print("* * * * *  * * *");
  pinMode(7, INPUT_PULLUP);
  timerstart=millis();
  timerinterval=250;
}
void loop() {
  // put your main code here, to run repeatedly:
  currenttime=millis();
  if((currenttime-timerstart>timerinterval))
{
  //reset
  timerstart=currenttime;

  lcd.setCursor(laser,1);
  lcd.print(" ");
  if(laser==15)
  {
    laser_step=-1;
  }
  else if(laser==0)
  {
    laser_step=1;
  }
  laser+=laser_step;
  lcd.setCursor(laser,1);
  lcd.print("^");
}
  // check the button for stars
  if(digitalRead(7)==LOW)
  {
    lcd.setCursor(laser,0);
    lcd.print(" ");

   
  }
  delay(500);
  
}