File content as of revision 0:186bb2174995:

/* Copyright (c) 2012 Nick Ryder, University of Oxford
 * nick.ryder@physics.ox.ac.uk
 *
 *  MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
 * and associated documentation files (the "Software"), to deal in the Software without restriction, 
 * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or 
 * substantial portions of the Software.
 *
 * 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 "mbed.h"

#include "RangeFinder.h"

// Seeed ultrasound range finder
RangeFinder rf(p21, 10, 5800.0, 100000);
DigitalOut led(LED1);

int main()  {
    led = 1;
    float d;
    while (1)   {
        d = rf.read_m();
        if (d == -1.0)  {
            printf("Timeout Error.\n");   
        } else if (d > 5.0) {  
            // Seeed's sensor has a maximum range of 4m, it returns
            // something like 7m if the ultrasound pulse isn't reflected. 
            printf("No object within detection range.\n");
        } else  {
            printf("Distance = %f m.\n", d);
        }
        wait(0.5);
        led = !led;
    }
}