const int ledpins[6] = {A5, A4, A3, A2, A1, A0};
const int potentiometerPinName = A6;

void setup() {
  // put your setup code here, to run once:
  for (int i = 0; i < 6; i++) {
    pinMode(ledpins[i], OUTPUT);
    digitalWrite(ledpins[i], LOW);
  }
  Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
  int potRawValue = analogRead(potentiometerPinName);
  int rpm = map(potRawValue, 0, 1023, 0, 7000);
  Serial.println(rpm); 

  if(rpm < 4500) {
    for (int i = 0; i < 6; i++) digitalWrite(ledpins[i], LOW);
  }
  else if (rpm < 5500) {
    for (int i = 0; i < 2; i++) digitalWrite(ledpins[i], HIGH);
    for (int i = 2; i < 6; i++) digitalWrite(ledpins[i], LOW);
  }
  else if (rpm < 6500) {
    for (int i = 0; i < 4; i++) digitalWrite(ledpins[i], HIGH);
    for (int i = 4; i < 6; i++) digitalWrite(ledpins[i], LOW);
  }
  else {
    for (int i = 0; i < 6; i++) digitalWrite(ledpins[i], HIGH);
  }
}