Simple test of a VU-Metre

metre-test.ino

#define PWM_CNT 2

int pwm_pins[] = {5, 6};
int value = 0;
boolean falling = false;

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

void loop() {
  for (int x = 0; x<PWM_CNT; x++) {
    if (x == 1) {
      analogWrite(pwm_pins[x], value);
    }
    else {
      // Take value times 20 if led
      analogWrite(pwm_pins[x], min(value*20, 255));
    }
  }

  Serial.print("V: ");
  Serial.print(value);
  Serial.println();
  
  if (falling) {
    value -= 1;
    falling = value == 0 ? false : true;
  } else {
    value += 1;
    falling = value != 13 ? false : true;
  }
  
  delay(80);
}