void setup() {
  pinMode(13, OUTPUT);   // Pin 13 = Ausgang
}

void loop() {
  digitalWrite(13, HIGH); // LED an
  delay(1000);            // 1 Sekunde warten
  digitalWrite(13, LOW);  // LED aus
  delay(1000);            // 1 Sekunde warten
}

digitalWrite(13, HIGH);  // LED an
digitalWrite(13, LOW);   // LED aus
delay(100);              // 100 Millisekunden warten

void setup() {
  pinMode(2, OUTPUT); // Rot
  pinMode(3, OUTPUT); // Gelb
  pinMode(4, OUTPUT); // Grün
}
void loop() {
  digitalWrite(2, HIGH); delay(3000);      // ROT
  digitalWrite(3, HIGH); delay(1000);      // ROT+GELB
  digitalWrite(2, LOW);  digitalWrite(3, LOW);
  digitalWrite(4, HIGH); delay(3000);      // GRÜN
  digitalWrite(4, LOW);
  digitalWrite(3, HIGH); delay(1000);      // GELB
  digitalWrite(3, LOW);
}

void setup() {
  pinMode(7, INPUT);    // Taster = Eingang
  pinMode(13, OUTPUT);  // LED = Ausgang
}
void loop() {
  if (digitalRead(7) == HIGH) {
    digitalWrite(13, HIGH); // Taster gedrückt → LED an
  } else {
    digitalWrite(13, LOW);  // Taster los → LED aus
  }
}

void setup() { pinMode(9, OUTPUT); }

void loop() {
  int wert = analogRead(A0);    // 0 – 1023
  int hell = wert / 4;          // → 0 – 255
  analogWrite(9, hell);         // PWM-Ausgabe
}

void setup() {
  pinMode(8, OUTPUT); // Buzzer
  pinMode(7, INPUT);  // Taster
}
void loop() {
  if (digitalRead(7) == HIGH) {
    digitalWrite(8, HIGH); delay(200);
    digitalWrite(8, LOW);  delay(200);
  } else {
    digitalWrite(8, LOW);
  }
}

Serial.begin(9600);        // Monitor starten
delay(random(2000,5000));  // Zufällig warten
digitalWrite(LED, HIGH);   // LED an!
long start = millis();     // Zeit merken
// → auf Taster warten...
long reaktion = millis() - start;
Serial.println(reaktion);  // Ausgabe in ms

void punkt() {          // ·  kurz
  digitalWrite(13, HIGH); delay(200);
  digitalWrite(13, LOW);  delay(200);
}
void strich() {         // –  lang
  digitalWrite(13, HIGH); delay(600);
  digitalWrite(13, LOW);  delay(200);
}
// SOS: · · · — — — · · ·
void loop() {
  punkt(); punkt(); punkt(); delay(400); // S
  strich();strich();strich();delay(400); // O
  punkt(); punkt(); punkt(); delay(2000);// S
}

int startPin = 2, endPin = 6, pause = 150;

void setup() {
  for (int i = startPin; i <= endPin; i++)
    pinMode(i, OUTPUT);
}
void loop() {
  for (int i = startPin; i <= endPin; i++) { // vorwärts
    digitalWrite(i, HIGH); delay(pause);
    digitalWrite(i, LOW);
  }
  for (int i = endPin; i >= startPin; i--) { // rückwärts
    digitalWrite(i, HIGH); delay(pause);
    digitalWrite(i, LOW);
  }
}

void farbe(int r, int g, int b) {
  analogWrite(9, r);
  analogWrite(10, g);
  analogWrite(11, b);
}
void loop() {
  farbe(255, 0,   0);   delay(500); // Rot
  farbe(0,   255, 0);   delay(500); // Grün
  farbe(0,   0,   255); delay(500); // Blau
  farbe(255, 255, 0);   delay(500); // Gelb
  farbe(0,   255, 255); delay(500); // Cyan
  farbe(255, 0,   255); delay(500); // Magenta
}

int tasten[] = {2, 3, 4, 5};
int toene[]  = {262, 294, 330, 349}; // C D E F

void loop() {
  bool gespielt = false;
  for (int i = 0; i < 4; i++) {
    if (digitalRead(tasten[i]) == HIGH) {
      tone(8, toene[i]);
      gespielt = true;
    }
  }
  if (!gespielt) noTone(8);
}

void loop() {
  digitalWrite(9, LOW);  delayMicroseconds(2);
  digitalWrite(9, HIGH); delayMicroseconds(10);
  digitalWrite(9, LOW);
  long us = pulseIn(10, HIGH);
  int cm = us * 0.034 / 2;
  Serial.print(cm); Serial.println(" cm");
  delay(500);
}

#include <Servo.h>
Servo schranke;
bool offen = false;

void setup() {
  schranke.attach(9);
  pinMode(7, INPUT);
  schranke.write(0); // geschlossen
}
void loop() {
  if (digitalRead(7) == HIGH) {
    delay(50); // Entprellung
    offen = !offen;
    schranke.write(offen ? 90 : 0);
    delay(500);
  }
}

bool muster[6][7] = {
  {0,0,0,1,0,0,0}, // 1 – Mitte
  {1,0,0,0,0,0,1}, // 2
  {1,0,0,1,0,0,1}, // 3
  {1,1,0,0,0,1,1}, // 4
  {1,1,0,1,0,1,1}, // 5
  {1,1,1,0,1,1,1}, // 6
};
// Würfeln:
int z = random(0, 6);
for (int i=0; i<7; i++)
  digitalWrite(pins[i], muster[z][i]);

#include <DHT.h>
DHT dht(2, DHT11);

void setup() { Serial.begin(9600); dht.begin(); }

void loop() {
  float t = dht.readTemperature();
  float h = dht.readHumidity();
  Serial.print(t); Serial.print(" C | ");
  Serial.print(h); Serial.println(" %");
  delay(2000);
}

// map(wert, vonMin, vonMax, bisMin, bisMax)
int w = analogRead(A0);           // 0–1023

if (w < 341) {
  analogWrite(9,  map(w, 0, 341, 255, 0));  // R↓
  analogWrite(10, map(w, 0, 341, 0, 255));  // G↑
} else if (w < 682) {
  analogWrite(10, map(w, 341, 682, 255, 0));// G↓
  analogWrite(11, map(w, 341, 682, 0, 255));// B↑
} else {
  analogWrite(11, map(w, 682,1023,255, 0)); // B↓
  analogWrite(9,  map(w, 682,1023, 0,255)); // R↑
}

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
int sek = 0;

void setup() { lcd.init(); lcd.backlight(); }

void loop() {
  lcd.setCursor(0, 0); lcd.print("Arduino Uhr:");
  lcd.setCursor(0, 1);
  lcd.print(sek/60);  lcd.print("m ");
  lcd.print(sek%60);  lcd.print("s   ");
  sek++; delay(1000);
}

int messeEntfernung() {
  digitalWrite(9, LOW);  delayMicroseconds(2);
  digitalWrite(9, HIGH); delayMicroseconds(10);
  digitalWrite(9, LOW);
  return pulseIn(10, HIGH) * 0.034 / 2;
}

void loop() {
  int d = messeEntfernung();
  if      (d > 30) { /* grün, kein Ton */ }
  else if (d > 15) { /* gelb, langsam  */ }
  else if (d > 5)  { /* rot, schnell   */ }
  else             { /* alle, Dauerton */ }
}