bool phase = false;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(17, INPUT);
}

void loop() {
  int i = digitalRead(17);

  if(i == HIGH){
    if(!phase){
    Serial.println("Moved");
    phase = true;
  }
  }
  else{

    if(phase){

      Serial.println("Motion ended");
      phase = false;
    }
  }
}