int rev = 12;
int ledGr1 = 5;
int ledGr2 = 13;
int ledGr3 = 11;
int ledG1 = 6;
int ledG2 = 9;
int ledRo = 3;
int ledBl = 10;
int ledAll = 8;
unsigned long duration;
unsigned long rpm;

void setup(){
  Serial.begin(19200);
  pinMode(8, OUTPUT);
  pinMode(rev, INPUT);
}
void loop(){
  Serial.print("Drehzahl: ");
  Serial.println(rpm);
  duration = pulseIn(rev, HIGH);
  rpm = 30000000 / duration;

  if (rpm > 6800 && rpm < 10000) {
    digitalWrite(ledAll, HIGH);
    delay(5);
    digitalWrite(ledAll, LOW);
    delay(80);
  }
  if (rpm > 5200) analogWrite(ledGr1, 5);
  if (rpm < 5150 || rpm > 6800) analogWrite(ledGr1, 0);
  if (rpm > 5600) analogWrite(ledGr2, 5);
  if (rpm < 5550 || rpm > 6800) analogWrite(ledGr2, 0);
  if (rpm > 6000) analogWrite(ledGr3, 5);
  if (rpm < 5950 || rpm > 6800) analogWrite(ledGr3, 0);
  if (rpm > 6250) analogWrite(ledG1, 7);
  if (rpm < 6200 || rpm > 6800) analogWrite(ledG1, 0);
  if (rpm > 6250) analogWrite(ledG2, 20);
  if (rpm < 6200 || rpm > 6800) analogWrite(ledG2, 0);
  if (rpm > 6450) analogWrite(ledRo, 10);
  if (rpm < 6400 || rpm > 6800) analogWrite(ledRo, 0);
  if (rpm > 6600) analogWrite(ledBl, 5);
  if (rpm < 6550 || rpm > 6800) analogWrite(ledBl, 0);
  delay(50);
}