Serial Monitor not displaying anything
Which one are you using?
The one closest to the reset button, I believe its the native...

This is more confusing than I realized. The Due has two ports:


Programming port
For programming, the programming port is easiest to use. And you can &quot;talk&quot; to the serial port using Serial, like this:
void setup ()
  {
  Serial.begin (115200);
  Serial.println (&quot;Hello, world!&quot;);
  }  // end of setup

void loop ()
  {
  }  // end of loop


Native USB port
This lets you emulate USB devices (eg. keyboard, mice). However if you want to use it for Serial communications you need to use a different class SerialUSB like this:
void setup ()
  {
  SerialUSB.begin(115200);
  while (!SerialUSB) ; // wait for it to become ready
  SerialUSB.println (&quot;Starting ...&quot;);
  }  // end of setup

unsigned long i;

void loop ()
  {
  SerialUSB.print (&quot;Hello, world! Count = &quot;);
  SerialUSB.println (++i);
  delay (1000);
  }  // end of loop

It also helps to wait for the serial port to become ready, as I did in setup. Otherwise you may miss the first 10 lines or so of serial output.