#define TX_PIN 7
#define LED_PIN 13

char *code = "1000100110110000000000010";
//char *code = "1011001001011111000000010";

void setup() {
   pinMode(LED_PIN, OUTPUT);
   pinMode(TX_PIN, OUTPUT);
}

void loop() {

  // we have to send same signal at least two times
  for(int repeat = 0; repeat < 5; repeat++ ) {
    
    digitalWrite(LED_PIN, HIGH);

    for(int i = 0; i < strlen(code); i++) {
      int i1 = 300;
      int i2 = 900;
      if (code[i] == '1' ) {
        i1 = 900;
        i2 = 300;
      }
      digitalWrite(TX_PIN, HIGH);
      delayMicroseconds(i1);
      digitalWrite(TX_PIN, LOW);
      delayMicroseconds(i2);
    }

    delayMicroseconds(2000); // guess
  }

  digitalWrite(LED_PIN, LOW);  
  delay(3000);
}