#include <LiquidCrystal.h>
#define LOW_PIN 13
#define EINGANG 12
const int rs = 11, en = 10, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

byte dauer;
long startZeit;
int reaktionsZeit;
int GLED = 8;
int RLED = 1;



void setup() {
  pinMode(GLED, OUTPUT);
  pinMode(LOW_PIN,OUTPUT);
  digitalWrite(LOW_PIN, LOW);
  pinMode(RLED, OUTPUT);
  pinMode(EINGANG, INPUT_PULLUP);
}

void loop() {
  dauer = random(2,5);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Push Button");
  while(digitalRead(EINGANG) == HIGH);
  {
    lcd.setCursor(0, 2);
    digitalWrite(GLED, HIGH);
    lcd.print("redLED on, push");
  delay(dauer * 1000);
  digitalWrite(GLED, LOW);
  digitalWrite(RLED, HIGH);
  startZeit = millis();
  while(digitalRead(EINGANG) == HIGH);
  reaktionsZeit = millis() - startZeit;
  digitalWrite(RLED, LOW);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("reactionTime ");
  lcd.print(reaktionsZeit);
  lcd.println(" ms");
  delay(1000);
  }
  }