File content as of revision 1:f6f3187e44c5:

#include "mbed.h"
PwmOut buzzer(p23);


// red light   
 float frequency[]= {500,0,500,0,500,0,500,0,500,0} ;//alarm frequency array


    float beat[]= {1,1,1,1,1,1,1,1,1,1};  //beat array
    int
       main()
    {
      while (1) {
        for (
            int
            i=0;
            i<=9 ;
            i++) {buzzer.period(1/(frequency[i]));                  // PMW period   1/frequency
            buzzer=0.5;                                             //50% duty cycle
            wait(0.5*beat[i]);                                      //hold for beat period
                }
    }            
 }



// yellow light

while (flag = 2);

{
    float frequency[]= {659,554,659,554,550,494,554,587,494,659,554,440};         //music frequency array


    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/(frequency[i]));                  // PMW period   1/frequency
            buzzer=0.5;                                             //50% duty cycle
            wait(0.5*beat[i]);                                      //hold for beat period
                }
    }            
 }
}




//green light

while (flag = 3);

{

     int main() {
            
            buzzer.period_ms(1);                     //1ms period    1k Hz //

            buzzer = 0;                           //0% duty cycle  //

}