Revision 1:2e6ea42675c7, committed 2014-10-21

Comitter:

4180_1

Date:

Tue Oct 21 03:00:15 2014 +0000

Parent:

0:b2fdf3770282

Commit message:

ver 1.0

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SongPlayer.h	Tue Oct 21 03:00:15 2014 +0000
@@ -0,0 +1,41 @@
+#include "mbed.h"
+// new class to play a note on Speaker based on PwmOut class
+class SongPlayer
+{
+public:
+    SongPlayer(PinName pin) : _pin(pin) {
+// _pin(pin) means pass pin to the constructor
+    }
+// class method to play a note based on PwmOut class
+    void PlaySong(float frequency[], float duration[], float volume=1.0) {
+        vol = volume;
+        notecount = 0;
+        _pin.period(1.0/frequency[notecount]);
+        _pin = volume/2.0;
+        noteduration.attach(this,&SongPlayer::nextnote, duration[notecount]);
+        // setup timer to interrupt for next note to play
+        frequencyptr = frequency;
+        durationptr = duration;
+        //returns after first note starts to play
+    }
+    void nextnote();
+private:
+    Timeout noteduration;
+    PwmOut _pin;
+    int notecount;
+    float vol;
+    float * frequencyptr;
+    float * durationptr;
+};
+//Interrupt Routine to play next note
+void SongPlayer::nextnote()
+{
+    _pin = 0.0;
+    notecount++; //setup next note in song
+    if (durationptr[notecount]!=0.0) {
+        _pin.period(1.0/frequencyptr[notecount]);
+        noteduration.attach(this,&SongPlayer::nextnote, durationptr[notecount]);
+        _pin = vol/2.0;
+    } else
+        _pin = 0.0; //turn off on last note
+}
\ No newline at end of file

--- a/Speaker.h	Sun Jan 20 03:02:37 2013 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,19 +0,0 @@
-#include "mbed.h"
-// new class to play a note on Speaker based on PwmOut class
-class Speaker
-{
-public:
-    Speaker(PinName pin) : _pin(pin) {
-// _pin(pin) means pass pin to the Speaker Constructor
-    }
-// class method to play a note based on PwmOut class
-    void PlayNote(float frequency, float duration, float volume) {
-        _pin.period(1.0/frequency);
-        _pin = volume/2.0;
-        wait(duration);
-        _pin = 0.0;
-    }
-
-private:
-    PwmOut _pin;
-};
\ No newline at end of file

--- a/main.cpp	Sun Jan 20 03:02:37 2013 +0000
+++ b/main.cpp	Tue Oct 21 03:00:15 2014 +0000
@@ -1,19 +1,32 @@
 #include "mbed.h"
-#include "Speaker.h"
+#include "SongPlayer.h"
 
-// Speaker test program - euro police style siren now using new Speaker class method
+// Song test program - plays a song using PWM and timer interrupts
 // for documentation see http://mbed.org/users/4180_1/notebook/using-a-speaker-for-audio-output/
-// can also be used to play a song, if you have the notes and durations
+// can be used to play a song, if you have the notes and durations
 // for musical note frequencies see http://en.wikipedia.org/wiki/Piano_key_frequencies
 
+//Set up notes and durations for sample song to play
+// A 0.0 duration note at end terminates song play
+float note[18]= {1568.0,1396.9,1244.5,1244.5,1396.9,1568.0,1568.0,1568.0,1396.9,
+                 1244.5,1396.9,1568.0,1396.9,1244.5,1174.7,1244.5,1244.5, 0.0
+                };
+float duration[18]= {0.48,0.24,0.72,0.48,0.24,0.48,0.24,0.24,0.24,
+                     0.24,0.24,0.24,0.24,0.48,0.24,0.48,0.48, 0.0
+                    };
+
+DigitalOut led1(LED1);
 int main()
 {
-// setup instance of new Speaker class, mySpeaker using pin 21
+// setup instance of new SongPlayer class, mySpeaker using pin 26
 // the pin must be a PWM output pin
-    Speaker mySpeaker(p21);
-    // loops forever playing two notes on speaker
+    SongPlayer mySpeaker(p26);
+// Start song and return once playing starts
+    mySpeaker.PlaySong(note,duration);
+    // loops forever while song continues to play to end using interrupts
     while(1) {
-        mySpeaker.PlayNote(969.0,0.5,0.5);
-        mySpeaker.PlayNote(800.0,0.5,0.5);
+        led1 = !led1;
+        wait(.1);
     }
 }
+