File content as of revision 0:35211a622a44:

#include "mbed.h"
#include "hcsr04.h"
#include "rev_Hcsr04.h"

#define DEBUG_TYPE 1
#define P_ uart.printf
#include "rev_config.h"


#define  CHECK_DISTANCE 1000

#if 0
int sum_dist[3] = {0,}; //ryuhs74@20150712 - 
int avg_dist = 0; //ryuhs74@20150712 - 
int index_dist = 0; //ryuhs74@20150712 - 
#endif

Serial uart(USBTX, USBRX); // tx, rx

HCSR04 sensor(D12, D11); 

DigitalOut led1(LED1); //server listning status
DigitalOut led2(LED2); //socket connecting status

//////////////////////////////////////////////////////////////////////////
Ticker ledTick;

//////////////////////////////////////////////////////////////////////////
void ledTickfunc()
{
    led1 = !led1;
}

//////////////////////////////////////////////////////////////////////////
int main()
{
    ledTick.attach(&ledTickfunc,0.5);

    uart.baud(115200);
    DM_fLN("Start ----> HCSR04");
    
    while(1) {
#if 0
        long distance = sensor.distance(); 

        //ryuhs74@20150712 START - 
        if( index_dist < 3){
            sum_dist[index_dist] = distance;
            DM_fLN("sum_dist[%d] = %d", index_dist, sum_dist[index_dist]);
            index_dist ++;
            wait_ms(200);
        } else {
            avg_dist = 0;
            index_dist = 0;

            for(int i =0; i<3;i++){
                avg_dist += sum_dist[i];
            }

            avg_dist /= 3;
            DM_fLN("average: %d", avg_dist);

            if( avg_dist <= CHECK_DISTANCE ){

            }
            wait_ms(1000);
        }
#else
        get_distance();
        wait_ms(1000);
#endif
    }
}