Prev: Download & Read your favorite ebooks with eReader JE200
Next: COMP.DSP 2010 pictures and presentations
From: Codefragment on 15 Apr 2010 08:35
Hello, I hope someone can help me with what is probably a simple questions,
but I am new at this!

I wrote code to generate a sine wave by using the clock interrupt. Now, I
have read a tutorial and think that this was the wrong way to do this
because the example shows running an interrupt based on the pwm itself.
What is the difference between how I wrote my code and the tutorial? (see
the code below)


The tutorial says
PieVectTable.T1CINT = &T1_Compare_isr;
PieCtrlRegs.PIEIER2.bit.INTx5 = 1;

where I did:


   PieVectTable.TINT0=&cpu_timer0_isr;
PieCtrlRegs.PIEIER1.bit.INTx7 = 1;

interrupt void cpu_timer0_isr(void)  
{  
  

   // Acknowledge this interrupt to receive more interrupts from group
1  
   CpuTimer0.InterruptCount++;  
    intervaltimer++;
    if (intervaltimer%1000==0)
    {
        newvalue++;
    }
    if (newvalue>100)
    {
        newvalue=0;
        t=0;
    }
    t=t+((2*pi)/(100)); // iterations of sin wave
    x=30000*sin(t); //Determines duty cycle based upon sin value
       if (x>0)
   {
       EvaRegs.CMPR1= (long int) x;
    EvaRegs.CMPR2=0;//sets pin to zero to drive motor forward
   }
   if(x<0)
   {
    EvaRegs.CMPR1=0;//0x0000;//sets pin to zero to drive motor
backwards
    EvaRegs.CMPR2= (long int) -x;
   }

    //x=sin(t); //Determines duty cycle based upon sin value

   PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;  
}  



 | 
Pages: 1
Prev: Download & Read your favorite ebooks with eReader JE200
Next: COMP.DSP 2010 pictures and presentations