Revision 0:1e4b66122368, committed 2011-03-12

Comitter:

rosienej

Date:

Sat Mar 12 22:26:10 2011 +0000

Child:

1:6996f66161d7

Commit message:

beta

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Ping.cpp	Sat Mar 12 22:26:10 2011 +0000
@@ -0,0 +1,54 @@
+#include "Ping.h"
+
+#include "mbed.h"
+
+Ping::Ping(PinName PING_PIN)
+        : _event(PING_PIN)
+        , _cmd(PING_PIN)
+        , _timer()
+        {
+            _event.rise(this,&Ping::_Starts);
+            _event.fall(this,&Ping::_Stops);
+            _SPEED_OF_SOUND_CM = 33;
+        } 
+        
+void Ping::_Starts(void)
+{
+      _Valid = false;  // start the timere, and invalidate the current time.
+      _Busy = true;
+      _timer.start();
+      _Time = _timer.read_us();      
+}
+
+void Ping::_Stops(void)
+{
+      _Valid = true;  // When it stops, update the time
+      _Busy = false;
+      _Time = _timer.read_us()-_Time;
+}
+
+void Ping::Send()
+{
+     
+     _cmd.output();
+     _cmd.write(0);  // see the ping documentation http://www.parallax.com/Portals/0/Downloads/docs/prod/acc/28015-PING-v1.6.pdf
+     wait_us(3);
+     _cmd.write(1);
+     wait_us(3);
+     _cmd.write(0);
+     _cmd.input();
+     
+}
+void Ping::Set_Speed_of_Sound(int SoS_ms )
+{
+     _SPEED_OF_SOUND_CM = SoS_ms;
+}
+
+int Ping::Read_cm()
+// -1 means not valid.
+{
+    if(_Valid && ~_Busy) 
+        return ((_Time*_SPEED_OF_SOUND_CM)/1000);
+    else 
+        return -1;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Ping.h	Sat Mar 12 22:26:10 2011 +0000
@@ -0,0 +1,93 @@
+/* mbed Ping Library
+ * Copyright (c) 2007-2010 rosienej
+ *
+ * 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.
+ */
+    
+ #ifndef MBED_PING_H
+ #define MBED_PING_H
+
+#include "mbed.h"
+/** Ping  class, based on an InterruptIn pin, and a timer
+ *  works with the parallax Ping))) sensor (www.parallax.com)
+ *
+ * Example:
+ * @code
+ * // Continuously send pings and read the sensor
+ * #include "mbed.h"
+ * #include "Ping.h"
+ * 
+ * Ping Pinger(p21);
+ * 
+ * int main() {
+ *     int range;
+ 
+ *     while(1) {
+ *  
+ *        Pinger.Send();    
+ *        wait_ms(30);
+ *        range = Pinger.Read_cm();
+ *     }
+ * }
+ * @endcode
+ */
+  class Ping {
+  public:
+   /** Create a Ping object connected to the specified InterruptIn pin
+    *
+    * @param PING_PIN InterruptIn pin to connect to 
+    */
+    Ping(PinName PING_PIN);
+    
+     /** Sends a Ping 
+      *
+      * @param none
+      */
+    void Send(void);
+    
+     /** Set the speed of sound, default 33 cm/ms 
+      *
+      * @param Speed of sound in centimeters per milliseconds
+      */
+    void Set_Speed_of_Sound(int SoS_ms);
+    
+    /** Read the result in centimeters
+      *
+      * @param none
+      */
+    int Read_cm(void);
+    
+  protected:
+    
+    InterruptIn     _event;
+    DigitalInOut    _cmd;
+    Timer           _timer;
+
+    bool _Valid;
+    bool _Busy;
+    int  _Time;
+    int  _SPEED_OF_SOUND_CM; /* in milliseconds */
+    
+    void _Starts(void);
+    void _Stops(void);
+    
+  };
+  
+  #endif
+  
\ No newline at end of file