Using a FIR_Filter off-line

[Anonymous]

Hi,

   

i would like to off-line-filter a sampled array using a FIR-filter, for this i worte a simple code:

   

Filter_1_Start();
    // Enable the interrupt register bit to poll
    // Value 1 for Channel A, Value 2 for Channel B
    Filter_1_INT_CTRL_REG |= (1 << Filter_1_CHANNEL_A);

   

for(n=0; n < N_s; n++)
            {
                Filter_1_Write16(Filter_1_CHANNEL_A, ADC_res);
                while (Filter_1_IsInterruptChannelA() == 0) ;
                ADC_FIR = Filter_1_Read16(Filter_1_CHANNEL_A);
            }

       

But what i've got is a zero-array ADC_FIR = 0

   

anyone any idea why?

       

thanks in advance

   

Hosam

   

Ps. i attached the Project, see below

   

the problem is a task in a bigger project, i hoppe, the description is clear enough

[Anonymous]

I would declare these as volatile as they are used in an interrupt

   

routine -

       

extern int16 ADC_res[128];
extern int16 ADC_FIR[128];
extern uint16  i;

           

          http://www.barrgroup.com/Embedded-Systems/How-To/C-Volatile-Keyword    Volatile

       

Insofar as output array being 0, one can assume your input signal was

   

in the passband ? You have confirmed input array from SAR looks right ?

       

Lastly the SAR is set up 800K SPS. That might be a tad too fast

   

to guarentee that your polling gets the sample before its overwritten

   

by the DFB. Maybe a DMA approach might make more sense.

       

Regards, Dana.

[Anonymous]

Hi,

   

thanks Dana fro your hin

   

i checked the ADC_res[128], the values of the SAR are as axpected and the signal IS in the passband(Signal freq. 90 KHz)

   

so it should work but it dosen't

   

i thik it could be the configuration of the filter, but i didn't find it out

   

Regards

   

Hosam

[ETRO_SSN583]

Hosam, I am at a loss for error, consider posting a CASE and if

   

you have time post the results back here, I am curious as to what

   

the issue is -

               

To create a technical case at Cypress -

       

www.cypress.com

   

“Support”

   

“Technical Support”

   

“Create a Case”

       

You have to be registered on Cypress web site first.

       

Regards, Dana.