title: Arduino Sim900 with no echo but SMS was sent out
body: <p>I just got a new Sim900 and connected to an Arduino Uno.  I used the code below to send a text to myself.  I received the text on my cell, but I did not receive any echo on my serial monitor (ie. "OK").  I have tried swapping the RX/TX pins and different baud rates with no success.</p>
  
  <hr>
  
  <pre><code>void setup()
  {
    Serial.begin(9600);  //Baud rate of the GSM/GPRS Module 
    Serial.println("");
    delay(2000);                  
    Serial.println("AT+CMGF=1");    
    delay(1000);
    Serial.println("AT+CMGS=\"+120########\"");    //Number to which you want to send the sms
    delay(1000);
    Serial.print("This is a test.");   //The text of the message to be sent
    delay(1000);
    Serial.write(0x1A); // send CTRL - z to end message
    Serial.write(0x0D); // Carriage Return
    Serial.write(0x0A); // Line Feed
    delay(5000); 
   }
  
  void loop()
  {
  }
  </code></pre>