#define DELAY 17 //9600bps

void setup() {
  pinMode(1, OUTPUT);
}

void loop() {
  //Envia bit de idle
  digitalWrite(1, HIGH);
  delayMicroseconds(500);
  //Envia bit de start
  digitalWrite(1, LOW);
  delayMicroseconds(DELAY);
  //Inicia envio pelo LSB
  digitalWrite(1, LOW);
  delayMicroseconds(DELAY);
  digitalWrite(1, LOW);
  delayMicroseconds(DELAY);
  digitalWrite(1, HIGH);
  delayMicroseconds(DELAY);
  digitalWrite(1, HIGH);
  delayMicroseconds(DELAY);
  digitalWrite(1, LOW);
  delayMicroseconds(DELAY);
  digitalWrite(1, LOW);
  delayMicroseconds(DELAY);
  digitalWrite(1, HIGH);
  delayMicroseconds(DELAY);
  digitalWrite(1, LOW);
  delayMicroseconds(DELAY);

  //Envia bit de stop
  digitalWrite(1, LOW);
  delayMicroseconds(DELAY);

  delay(500);
}