vmeter

#define DOT      1     // DOT = 1 Si accende solo un led alla volta
#define NUM_LEDS 9
const byte led[NUM_LEDS] = { 4, 5, 6, 7, 8, 9, 10, 11, 12};

void setup() {
  for(int i=0; i<NUM_LEDS; i++) {
    pinMode((const byte) led[i], OUTPUT);
  }
  Serial.begin(9600);
}

void loop() {
  vMeter();
delay(100);
}


void vMeter(){
  volatile uint16_t leds;
  static uint8_t currentStep = 0;

  uint8_t newStep = map(analogRead(A0), 0, 1023, 0, NUM_LEDS);
  newStep = constrain(newStep, 0, NUM_LEDS);
  if(newStep != currentStep){
    if(currentStep - newStep > 0)
      currentStep -= 1;
    else
      currentStep += 1;
  }

  leds = 0;
  if(DOT == 0){
    for (int n=1; n<=NUM_LEDS ; n++) {
      if (currentStep >= n)
        bitClear(leds, n-1);
    }
  }
  else {
    for(int n=1; n<=NUM_LEDS ; n++) {
    if(currentStep >= n){
      bitClear(leds, n-1);
      if(n>1)
        bitSet(leds, n-2);
      }
    }
  }

  for(int i=0; i<NUM_LEDS; i++) {
    boolean isBitSet = leds & (1 << i);
    digitalWrite(led[i], isBitSet);
  }
  Serial.println(leds, BIN);
}