void setup() {
  // put your setup code here, to run once:
pinMode(8, OUTPUT);
pinMode(7, INPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
int s = digitalRead(7);
if (s==HIGH) {
    int sinalLed = digitalRead(8);
    digitalWrite(8, not sinalLed);
    delay(500);
    Serial.print(".");
}
}