04-07 OrangesAndLemons

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Revision as of 15:16, 14 August 2014

This example uses a PWM to play the tune "Oranges and Lemons" on a piezo buzzer using a PWM.

/*Program Example 4.7: Plays the tune "Oranges and Lemons" on a piezo buzzer, using PWM
                                                                         */
#include "mbed.h"
PwmOut buzzer(PWM1);

//frequency array
float frequency[]= {659,554,659,554,440,494,554,587,494,659,554,440};
float beat[]= {1,1,1,1,1,0.5,0.5,1,1,1,1,2};             //beat array

int main()
{
   while (1) {
       for (int i=0; i<=11; i++) {
           buzzer.period(1/(2*frequency[i]));                 // set PWM period
           buzzer=0.5;                                        // set duty cycle
           wait(0.4f*beat[i]);                                 // hold for beat period
       }
   }
}

Schematic for example 04-07