File content as of revision 0:a17e0e0a506a:

#include "PwmSpeaker.h"

PwmSpeaker::PwmSpeaker(PinName pin) : _pin(pin) {
    // _pin(pin) means pass pin to the Speaker Constructor
}

// class method to play a note based on PwmOut class
void PwmSpeaker::playNote(float frequency, float duration, float volume) {
    _pin.period(1.0/frequency);
    _pin = volume/2.0; //50% duty cycle - max volume
    wait(duration);
    _pin = 0.0; //turn off note
}

// generate a short 150Hz tone using PWM hardware output
// something like this can be used for a button click effect for feedback
    //for (i=0; i<10; i++) {
//        speaker.period(1.0/150.0); // 500hz period
//        speaker =0.25; //25% duty cycle - mid range volume
//        wait(.02);
//        speaker=0.0; // turn off audio
//        wait(0.5);
//    }
// sweep up in frequency by changing the PWM period
    //for (i=0; i<8000; i=i+100) {
//        speaker.period(1.0/float(i));
//        speaker=0.25;
//        wait(.1);
//    }
//    wait(2);
// two tone police siren effect -  two periods or two frequencies
// increase volume - by changing the PWM duty cycle
//    for (i=0; i<26; i=i+2) {
//        speaker.period(1.0/969.0);
//        speaker = float(i)/50.0;
//        wait(.5);
//        speaker.period(1.0/800.0);
//        wait(.5);
//    }
//// decrease volume
//    for (i=25; i>=0; i=i-2) {
//        speaker.period(1.0/969.0);
//        speaker = float(i)/50.0;
//        wait(.5);
//        speaker.period(1.0/800.0);
//        wait(.5);
//    }
//    speaker =0.0;
//    wait(2);
//}