ultrasonic.hpp

/*
 * Author: Jun Kato <i@junkato.jp>
 * Copyright (c) 2015 Jun Kato.
 *
 * Thanks to Seeed Studio for a working arduino sketch
 *
 * 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.
 */
#pragma once

#include <string>
#include <mraa/aio.h>
#include <mraa/gpio.h>
#include <sys/time.h>

#define HIGH                   1
#define LOW                    0

namespace upm {

class UltraSonic {
    public:
        UltraSonic (int pin);

        ~UltraSonic ();

        int getDistance ();

        std::string name()
        {
            return m_name;
        }

        bool working()
        {
            return m_doWork;
        }

    private:
        bool m_doWork; /* Flag to control blocking function while waiting for falling edge interrupt */
        mraa_gpio_context m_pinCtx;
        uint8_t m_InterruptCounter;
        struct timeval m_RisingTimeStamp;
        struct timeval m_FallingTimeStamp;
        std::string m_name;

        static void signalISR(void *ctx);

        void ackEdgeDetected ();
};

}