#define pulsador 32
#define led 14
#define pinPot 4

double t;
volatile bool pulsado = false;
volatile bool timer_activado = false;
volatile int counter = 0;
const uint32_t frequency = 1000000;  //1MHz
const uint8_t max_counter = 10;

hw_timer_t*timer = NULL;

void IRAM_ATTR leerPulsador() {
  digitalWrite(led, LOW);
  counter = 0;
  timerStart(timer);
}

void IRAM_ATTR TimerOn() {
  counter++;
  timer_activado = true;
}

void setup() {
  Serial.begin(115200);
  pinMode(pulsador, INPUT_PULLUP); // configures pulsador as an input with a PULL-UP resistor
  pinMode(led, OUTPUT);
  attachInterrupt(digitalPinToInterrupt(pulsador), leerPulsador, FALLING); 

  timer = timerBegin(frequency);
  timerAttachInterrupt(timer, &TimerOn);
  timerAlarm(timer, 500000, true, 0);
  timerStop(timer);
}

void loop() {
  if (timer_activado) {
    if(counter < max_counter) {
      digitalWrite(led, !digitalRead(led));
    }
    else if (counter == max_counter) {
      digitalWrite(led, !digitalRead(led));
      counter = 0;
      timerStop(timer);
    }
    timer_activado = false;
  }

  int v = analogRead(pinPot);  //Lee el valor analógico que hay en el pin 4 y lo guarda en v
  double frecuencia = 1.0/((millis()-t)/1e3);
  Serial.print("Frecuencia:  ");
  Serial.println(frecuencia);
  Serial.println(v);
  t = millis();
  
  delay(50); //20Hz
}