File content as of revision 0:c9c3c570d34c:

 /*Program Example 9: Metronome. Uses Ticker to set beat rate
 */
 #include "mbed.h"
 #include <stdio.h>
 Serial pc(USBTX, USBRX);
 DigitalIn button(PC_13);
 DigitalIn dir(D4,PullDown);
 DigitalOut redled(D8); //displays the metronome beat
 Ticker beat_rate; //define a Ticker, with name “beat_rate”
 void beat(void);
 float period (0.5); //metronome period in seconds, initial value 0.5
 int rate (120); //metronome rate, initial value 120
 int main()
 {
     pc.printf("\r\n");
     pc.printf("mbed metronome!\r\n");
     pc.printf("_______________\r\n");
     period = 1;
     redled = 1; //diagnostic
     wait(.1);
     redled = 0;
     beat_rate.attach(&beat, period); //initializes the beat rate
     //main loop checks buttons, updates rates and displays
     while(1) {
         if (button ==0) {
         if (dir)
         //increase rate by 4
         rate = rate + 4;
         else
         //decrease rate by 4
         rate = rate - 4;
     }
     if (rate > 208) //limit the maximum beat rate to 208
        rate = 208;
     if (rate < 40) //limit the minimum beat rate to 40
        rate = 40;
     period = 60/rate; //calculate the beat period
     pc.printf("metronome rate is %i\r", rate);
     //pc.printf("metronome period is %f\r\n", period); //optional check
     wait (0.5);
     }
 }
 void beat() //this is the metronome beat
 {
     beat_rate.attach(&beat, period); //update beat rate at this moment
     redled = 1;
     wait(.1);
     redled = 0;
 }