SRF05.h

00001 /* mbed SRF05 Ultrasonic Rangefiner Library
00002  * Copyright (c) 2007-2010, cstyles, sford
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_SRF05_H
00024 #define MBED_SRF05_H
00025 
00026 #include "mbed.h"
00027 
00028 /** Library for the SRF05 Ultrasonic range finder
00029  *
00030  * Example:
00031  * @code
00032  * // Print measured distance
00033  *
00034  * #include "mbed.h"
00035  * #include "SRF05.h"
00036  *
00037  * SRF05 srf(p9,p10);
00038  *
00039  * int main() {
00040  *     while(1) {
00041  *         printf("Measured : %.1f\n", srf.read());
00042  *         wait(0.2);
00043  *     }
00044  * }
00045  * @endcode
00046  */
00047 class SRF05 {
00048 public:
00049 
00050     /** Create a SRF05 object, connected to the specified pins
00051      *
00052      * @param trigger DigitalOut to the SRF05 trigger
00053      * @param echo InterruptIn to measure the return pulse
00054      */
00055     SRF05(PinName trigger, PinName echo);
00056     
00057     /** A non-blocking function that will return the last measurement
00058      *
00059      * @returns floating point representation of distance in cm
00060      */
00061     float read();
00062 
00063     /** A short hand way of using the read function */
00064     operator float();
00065     
00066 private :
00067     DigitalOut _trigger;
00068     InterruptIn _echo;
00069     Timer _timer;
00070     Ticker _ticker;
00071     void _rising (void);
00072     void _falling (void);
00073     void _startRange (void);
00074     float _dist;
00075 };
00076 
00077 #endif