File content as of revision 1:ed00e9c4ba6e:

#include "mbed.h"
#include "ultrasonic.h"
 
extern Timer timer2;

uint16_t ultrasonicVal[4];
double ultrasonicValue[ALL_ULTRASONIC] = {0};


void Ultrasonic()
{
    for(uint8_t i = 0 ; i < ALL_ULTRASONIC ; i++){
        uint8_t flag = 0;
    
        DigitalOut PingPinOut(ultrasonic_pin[i]);
        PingPinOut = 1;
        wait_us(10);
        PingPinOut = 0;
        DigitalIn PingPin(ultrasonic_pin[i]);
        timer2.reset();
        while(PingPin == 0){
            if(timer2.read_us() > 1500){   //1.5ms以上応答なし
                ultrasonicValue[i] =  PING_ERR;
                flag = 1;
                break;
            }
        } 
        timer2.reset();
        while(PingPin == 1){
            if((timer2.read_us() > 18500) || (flag == 1)){  //18.5ms以上のパルス
                ultrasonicValue[i] =  PING_ERR;
                flag = 1;
                break;
            }
        }
        if(flag == 0){
            ultrasonicValue[i] = timer2.read_us() / 1000000.0 / 2.0 * 340.0 * 1000.0; //mm  MAX:3145
            ultrasonicVal[i] = (int)(ultrasonicValue[i] * 10.0);
        }else{
            ultrasonicVal[i] = PING_ERR;
        }
    }
}