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      1 /*
      2  * Author: Yevgeniy Kiveisha <yevgeniy.kiveisha (at) intel.com>
      3  * Author: Rafael Neri <rafael.neri (at) gmail.com>
      4  * Copyright (c) 2014-2015 Intel Corporation.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining
      7  * a copy of this software and associated documentation files (the
      8  * "Software"), to deal in the Software without restriction, including
      9  * without limitation the rights to use, copy, modify, merge, publish,
     10  * distribute, sublicense, and/or sell copies of the Software, and to
     11  * permit persons to whom the Software is furnished to do so, subject to
     12  * the following conditions:
     13  *
     14  * The above copyright notice and this permission notice shall be
     15  * included in all copies or substantial portions of the Software.
     16  *
     17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     20  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     24  */
     25 
     26 #include <iostream>
     27 #include <string>
     28 #include <stdexcept>
     29 #include <unistd.h>
     30 #include <stdlib.h>
     31 #include <functional>
     32 
     33 #include "hcsr04.h"
     34 
     35 using namespace upm;
     36 
     37 #ifdef JAVACALLBACK
     38 HCSR04::HCSR04 (uint8_t triggerPin, uint8_t echoPin, IsrCallback *cb)
     39 {
     40         HCSR04 (triggerPin, echoPin, generic_callback_isr);
     41 }
     42 #endif
     43 
     44 HCSR04::HCSR04 (uint8_t triggerPin, uint8_t echoPin, void (*fptr)(void *)) {
     45     mraa_result_t error  = MRAA_SUCCESS;
     46     m_name              = "HCSR04";
     47 
     48     m_triggerPinCtx     = mraa_gpio_init (triggerPin);
     49     if (m_triggerPinCtx == NULL) {
     50         throw std::invalid_argument(std::string(__FUNCTION__) +
     51                                     ": mraa_pwm_init() failed, invalid pin?");
     52         return;
     53     }
     54 
     55     mraa_gpio_dir(m_triggerPinCtx, MRAA_GPIO_OUT);
     56     mraa_gpio_write (m_triggerPinCtx, 0);
     57 
     58     m_echoPinCtx = mraa_gpio_init(echoPin);
     59     if (m_echoPinCtx == NULL) {
     60         throw std::invalid_argument(std::string(__FUNCTION__) +
     61                                     ": mraa_gpio_init() failed, invalid pin?");
     62         return;
     63     }
     64 
     65     mraa_gpio_dir(m_echoPinCtx, MRAA_GPIO_IN);
     66     mraa_gpio_isr(m_echoPinCtx, MRAA_GPIO_EDGE_BOTH, fptr, NULL);
     67 }
     68 
     69 HCSR04::~HCSR04 () {
     70     mraa_result_t error = MRAA_SUCCESS;
     71 
     72     error = mraa_gpio_close (m_triggerPinCtx);
     73     if (error != MRAA_SUCCESS) {
     74         mraa_result_print (error);
     75     }
     76 
     77     error = mraa_gpio_close (m_echoPinCtx);
     78     if (error != MRAA_SUCCESS) {
     79         mraa_result_print (error);
     80     }
     81 }
     82 
     83 double
     84 HCSR04::timing() {
     85     mraa_gpio_write (m_triggerPinCtx, 1);
     86     usleep(10);
     87     mraa_gpio_write (m_triggerPinCtx, 0);
     88 
     89     m_doWork = 0;
     90     m_InterruptCounter = 0;
     91     while (!m_doWork) {
     92         usleep (5);
     93     }
     94 
     95     return m_FallingTimeStamp - m_RisingTimeStamp;
     96 }
     97 
     98 void
     99 HCSR04::ackEdgeDetected () {
    100     struct timeval timer;
    101     gettimeofday(&timer, NULL);
    102 
    103     ++m_InterruptCounter;
    104     if (!(m_InterruptCounter % 2)) {
    105         m_FallingTimeStamp  = 1000000 * timer.tv_sec + timer.tv_usec;
    106         m_doWork = 1;
    107     } else {
    108         m_RisingTimeStamp = 1000000 * timer.tv_sec + timer.tv_usec;
    109     }
    110 }
    111 
    112 double
    113 HCSR04::getDistance(int sys)
    114 {
    115     double _timing = timing();
    116     if (sys)
    117     {
    118         return (_timing/2) / 29.1;
    119     } else {
    120         return (_timing/2) / 74.1;
    121     }
    122 }
    123