File content as of revision 0:3052351a8da9:

#include "mbed.h"
#include <math.h>
int i=1,N=50,q=0;

float wt=0;


float aout1=0,aout2=0;
AnalogOut aout(PA_4);
AnalogIn V_adc(PB_1);
float Vr_adc;
Serial pc(USBTX,USBRX);

DigitalOut myled(LED1);
   
Timer timer1; 

     
int main(){  
  
     pc.baud(128000);
     const float freq = 10;//50
     
    timer1.start();

    while(1) {
        Vr_adc=V_adc.read();
        if(Vr_adc<0.005f){
              N=1;
              }
        if((Vr_adc>0.005f)&&(Vr_adc<=0.1f)){
              N=2;
              }
       if((Vr_adc>0.1f)&&(Vr_adc<=0.2f)){
              N=5;
              }
        if((Vr_adc>0.2f)&&(Vr_adc<=0.4f)){
              N=10;
              }
       if((Vr_adc>0.4f)&&(Vr_adc<=0.6f)){
              N=20;
              }   
       if((Vr_adc>0.6f)&&(Vr_adc<=0.8f)){
              N=30;
              }
      if(Vr_adc>0.8f){
              N=60;
              }      
        float s = timer1.read();
        myled = ((int)s) % 2 == 0; /* LED output(0.5Hz) */
        wt=fmodf(s * freq, 1) * 3.14159265359 * 2;
        for(i=1;i<=2*N-1;i=i+2){
        //aout2 = VDD/2 +2/VDD* (sin(wt)+sin(3*wt)/3+sin(5*wt)/5+.......)
        if(i==0){
          aout1=sin((i-1)*wt)/(i-1);  //if i==N i even
          }
          else{
          aout1=sin(i*wt)/i;
          }
          aout2=aout2+aout1;
       
           }
         
          aout=0.1+(3.3/2+(2*3.3/3.14159265359)*aout2)/5; //VDD=3.3
          aout2=0;
          myled = !myled;
          if(q>100000){
           timer1.reset();
           q=0;
           }
           q++;
         //  if((q%100)==0){
            pc.printf("%.3f \r" ,aout*10);
         //  }

    }
  
       
       
       
}