Contagiros

volatile unsigned int pulsos = 0;
 volatile unsigned long t;
//-------------------------------
void ContaPulso()
{
  pulsos++;
}
//-----------------------------
void setup()
{
  Serial.begin(9600);
  attachInterrupt(0, ContaPulso, RISING);
  pinMode(2,INPUT_PULLUP);
  t = millis();
}
void loop()
//------------------------------
{
  if ((millis() - t) >= 1000)
  {
    int rpm = pulsos * 60;
    Serial.print("RPM = ");
    Serial.println(rpm);
    t = millis();
  }
  pulsos = 0;
}