void setup() {
  pinMode(6,OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(4, OUTPUT);
}

void loop() {
digitalWrite(6,HIGH); // led vermelho
delay(7000);
digitalWrite(6,LOW);
delay(1000);

digitalWrite(7,HIGH); // led verde
delay(7000);
digitalWrite(7,LOW);
delay(1000);

digitalWrite(5,HIGH); //led amarelo
delay(7000);
digitalWrite(5,LOW);
delay(1000);
}