main.cpp

00001 #include "mbed.h"
00002 
00003 //  Notes      
00004 #define A4      440        
00005 #define B4b     446         
00006 #define C4      261
00007 #define C4_1    130 
00008 #define C5      523      
00009 #define D4      293   
00010 #define D4b     277               
00011 #define E4      329          
00012 #define F4      349           
00013 #define G4      392  
00014  
00015 const int notes[] = {C4_1,C4,D4,C4,F4,E4,C4_1,C4,D4,C4,G4,F4,C4_1,C4,C5,A4,F4,E4,D4,B4b,B4b,A4,F4,G4,F4};
00016 const int intervals[] = {4, 4, 8, 8, 8, 10, 4, 4, 8, 8, 8, 10, 4, 4, 8, 8, 8, 8, 8, 4, 4, 8, 8, 8, 12};     
00017 
00018 // speaker sound effect demo using PWM hardware output
00019 PwmOut speaker(PA_0);
00020 // serail port to PC (over USB)
00021 Serial pc(USBTX, USBRX); // tx, rx
00022  
00023 int main()
00024 {
00025     int i;
00026     char c = 0;
00027     
00028     // Intro ( ta-dah @ 500Hz )
00029     speaker.period(1.0/500.0); // 500hz period
00030     speaker =0.5; //50% duty cycle - max volume
00031     wait(.05);
00032     speaker=0.0; // turn off audio
00033     wait(.05);
00034     speaker =0.5; //50% duty cycle - max volume
00035     wait(.5);
00036     speaker=0.0; // turn off audio
00037     
00038     pc.printf (" \n");
00039     pc.printf ("t=Tone, s=Sweep, p=Police, h=Song\n");
00040     
00041     while(c != ' ') {
00042        
00043        c=pc.getc();
00044        pc.printf("%c",c);
00045        wait(.1);
00046        
00047        switch (c)
00048        {
00049            case 't':
00050            pc.printf ("Tone...\n");
00051            // generate a short 150Hz tone using PWM hardware output
00052            // something like this can be used for a button click effect for feedback
00053            for (i=0; i<10; i++) {
00054               speaker.period(1.0/150.0); // 500hz period
00055               speaker =0.25; //25% duty cycle - mid range volume
00056               wait(.02);
00057            }
00058            speaker=0.0; // off
00059            break;
00060            
00061            case 's':
00062            pc.printf ("Sweep...\n");
00063            // sweep up in frequency by changing the PWM period
00064            for (i=0; i<8000; i=i+100) {
00065               speaker.period(1.0/float(i));
00066               speaker=0.25;
00067               wait(.02);
00068            }
00069            speaker=0.0; // off
00070            break;
00071 
00072            case 'p':
00073            pc.printf ("Police...\n");
00074            // two tone police siren effect - two periods or two frequencies
00075            // increase volume - by changing the PWM duty cycle
00076            for (i=0; i<10; i=i+2) {
00077               speaker.period(1.0/969.0);
00078               speaker = float(i)/50.0;
00079               wait(.5);
00080               speaker.period(1.0/800.0);
00081               wait(.5);
00082            }
00083            speaker=0.0; // off
00084            break;
00085            
00086            case 'h':
00087            pc.printf ("Happy birthday...\n");
00088            for (int i=0;i<=24;i++) {
00089                speaker.period(1.0/notes[i]);
00090                speaker=0.25;
00091                wait(0.8*intervals[i]/10);
00092            }
00093            speaker=0.0; // off
00094            break;
00095       }
00096    }
00097    pc.printf ("Bye...\n");
00098 }