main.cpp

#include <mbed.h>

int main() {

  // put your setup code here, to run once:

  //Setup Onboard LED
  DigitalOut firstLED(LED1);

  //Setup External LED connected to Digital Pin 6
  DigitalOut secondLED(D6);


  while(1) {
    // put your main code here, to run repeatedly:
    printf("Loop\n");
    firstLED = 1;
    thread_sleep_for(500);
    secondLED = 1;
    thread_sleep_for(500);
    firstLED = 0;
    thread_sleep_for(500);
    secondLED = 0;
    thread_sleep_for(500);
  }
}