#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 20, 4);

int buttonPin = 23;
int ledPinGreen = 5;
int ledPinRed = 4;

int x = 0; // Reaktionszeit in Millisekunden
unsigned long startTime;
bool buttonPressed = false;

void setup() {
  LCD.init();
  LCD.backlight();
  LCD.setCursor(1, 0);
  LCD.println("--Reaktions Test--");
  LCD.setCursor(1, 1);
  LCD.println("------------------");
  LCD.setCursor(1, 2);
  LCD.println("Druecken wenn LED");
  LCD.setCursor(1, 3);
  LCD.println("gruen ist.");

  pinMode(ledPinGreen, OUTPUT);
  pinMode(ledPinRed, OUTPUT);
  pinMode(buttonPin, INPUT);
}

void loop() {
  digitalWrite(ledPinRed, HIGH);
  delay(random(2000, 7000));
  digitalWrite(ledPinRed, LOW);
  digitalWrite(ledPinGreen, HIGH);
  startTime = millis(); // Startzeit aufzeichnen
  buttonPressed = false;
  
  while (!buttonPressed) {
    if (digitalRead(buttonPin) == HIGH) {
      x = millis() - startTime; // Reaktionszeit berechnen
      buttonPressed = true;
      digitalWrite(ledPinGreen, LOW);
    }
  }
  LCD.clear();
  LCD.setCursor(1, 0);
  LCD.println("Reaktionszeit: ");
  LCD.setCursor(1, 1);
  LCD.print(x);
  LCD.setCursor(1, 2);
  LCD.print("Millisekunden.");

  delay(3000);
  
  digitalWrite(ledPinRed, HIGH);
  delay(2000);
  digitalWrite(ledPinRed, LOW);
  LCD.clear();
  LCD.setCursor(1, 1);
  LCD.println("------------------");
  LCD.setCursor(1, 2);
  LCD.println("Naechster Versuch");
  LCD.setCursor(1, 3);
  LCD.println("------------------");
}