Ping.h

00001 /* mbed Ping Library
00002  * Copyright (c) 2007-2010 rosienej
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020  * THE SOFTWARE.
00021  */
00022     
00023  #ifndef MBED_PING_H
00024  #define MBED_PING_H
00025 
00026 #include "mbed.h"
00027 /** Ping  class, based on an InterruptIn pin, and a timer
00028  *  works with the parallax Ping))) sensor (www.parallax.com)
00029  *
00030  * Example:
00031  * @code
00032  * // Continuously send pings and read the sensor
00033  * #include "mbed.h"
00034  * #include "Ping.h"
00035  * 
00036  * Ping Pinger(p21);
00037  * 
00038  * int main() {
00039  *     int range;
00040  
00041  *     while(1) {
00042  *  
00043  *        Pinger.Send();    
00044  *        wait_ms(30);
00045  *        range = Pinger.Read_cm();
00046  *     }
00047  * }
00048  * @endcode
00049  */
00050 class Ping {
00051   public:
00052    /** Create a Ping object connected to the specified InterruptIn pin
00053     *
00054     * @param PING_PIN InterruptIn pin to connect to 
00055     */
00056     Ping(PinName PING_PIN);
00057     
00058      /** Sends a Ping 
00059       *
00060       * @param none
00061       */
00062     void Send(void);
00063     
00064      /** Set the speed of sound, default 33 cm/ms 
00065       *
00066       * @param Speed of sound in centimeters per milliseconds
00067       */
00068     void Set_Speed_of_Sound(int SoS_ms);
00069     
00070     /** Read the result in centimeters
00071       *
00072       * @param none
00073       */
00074     int Read_cm(void);
00075     
00076   protected:
00077     
00078     InterruptIn     _event;
00079     DigitalInOut    _cmd;
00080     Timer           _timer;
00081 
00082     bool _Valid;
00083     bool _Busy;
00084     int  _Time;
00085     int  _SPEED_OF_SOUND_CM; /* in milliseconds */
00086     
00087     void _Starts(void);
00088     void _Stops(void);
00089     
00090   };
00091   
00092   #endif
00093