#include <Ticker.h>

#define SIGNAL_PIN D2

Ticker flipper;

void setup()
{
  Serial.begin(9600);
  pinMode(SIGNAL_PIN, INPUT);
  digitalWrite (SIGNAL_PIN, LOW);


}

void flip(){
  Serial.println("From callback");
  digitalWrite (SIGNAL_PIN, HIGH);
}


void loop() {
  if(digitalRead(SIGNAL_PIN)==HIGH) {
    Serial.println("Movement detected.");
    flipper.attach(1, flip);
  } else {
    Serial.println("Did not detect movement.");
    flipper.detach();
  }
  delay(1000);
}