File content as of revision 2:e0b9fd6126d1:

/*
 * mbed Application program for the mbed ST NUCLEO F401RE Board  
 * Test program -> Check LED & Serial com.
 *
 * Copyright (c) 2014 Kenji Arai / JH1PJL
 *  http://www.page.sannet.ne.jp/kenjia/index.html
 *  http://mbed.org/users/kenjiArai/
 *      Created: July      12th, 2014
 *      Revised: July      12th, 2014
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

//  Include ---------------------------------------------------------------------------------------
#include "mbed.h"

//  Object ----------------------------------------------------------------------------------------
Serial pc(SERIAL_TX, SERIAL_RX);
DigitalOut myled(LED1);

//-------------------------------------------------------------------------------------------------
//  Control Program
//-------------------------------------------------------------------------------------------------
int main() {
  int i = 1;
  pc.printf("\r\nHello World !\r\n");
  pc.printf(" by JH1PJL "__DATE__"\r\n");
  while(1) { 
      pc.printf("This program runs since %d seconds.\r\n", i++);
      myled = !myled;
      wait(1.0);
  }
}