Signal Processing on TIVA C launchpad

Hey,
Have anyone done signal processing on TIVA C launchpad???

On 2/28/2016 11:18 PM, SHREYAS BELGAVE wrote:
> Hey,
> Have anyone done signal processing on TIVA C launchpad???

I saw your post in c.dsp.  Same question here.  What do you need help 
with?  This is just a CM4 and does DSP, sort of.  Not as efficient as a 
DSP but can come close for some apps like FIR filters.

-- 

Rick

On Monday, February 29, 2016 at 10:34:52 AM UTC+5:30, rickman wrote:
> On 2/28/2016 11:18 PM, SHREYAS BELGAVE wrote:
> > Hey,
> > Have anyone done signal processing on TIVA C launchpad???
> 
> I saw your post in c.dsp.  Same question here.  What do you need help 
> with?  This is just a CM4 and does DSP, sort of.  Not as efficient as a 
> DSP but can come close for some apps like FIR filters.
> 
> -- 
> 
> Rick


I have got the function for FIR filter from CMSIS library for TIVA C board.

I want to do a high pass filter having cutoff freq 1KHz. 
after applying function I am getting signal (i.e. array a[1024]) in frequency domain

so my question is from that how would i know that which a[i] is for the 1Khz freq below which i can suppress the signal and  agin i can do ifft and get the original signal.??

SHREYAS BELGAVE <spbelgave77@gmail.com> writes:
> I have got the function for FIR filter from CMSIS library for TIVA C board.
> I want to do a high pass filter having cutoff freq 1KHz. 
> after applying function I am getting signal (i.e. array a[1024]) in
> frequency domain

If I understand what you're asking, there's no FIR filter that will
totally eliminate signal just above the cutoff.  So this isn't a
programming problem-- it's a matter of understanding how signal
processing works.

On 3/7/2016 2:36 AM, SHREYAS BELGAVE wrote:
> On Monday, February 29, 2016 at 10:34:52 AM UTC+5:30, rickman wrote:
>> On 2/28/2016 11:18 PM, SHREYAS BELGAVE wrote:
>>> Hey, Have anyone done signal processing on TIVA C launchpad???
>>
>> I saw your post in c.dsp.  Same question here.  What do you need
>> help with?  This is just a CM4 and does DSP, sort of.  Not as
>> efficient as a DSP but can come close for some apps like FIR
>> filters.
>>
>> --
>>
>> Rick
>
>
> I have got the function for FIR filter from CMSIS library for TIVA C
> board.
>
> I want to do a high pass filter having cutoff freq 1KHz. after
> applying function I am getting signal (i.e. array a[1024]) in
> frequency domain
>
> so my question is from that how would i know that which a[i] is for
> the 1Khz freq below which i can suppress the signal and  agin i can
> do ifft and get the original signal.??

If I understand, you are asking how to come up with the coefficients 
(a[i]) for a high pass filter with a corner frequency of 1 kHz?  Or is 
a[i] the signal data in which case I don't understand your question.

Also, part of your post makes it seem like you think a filter will 
transform the time input signal to an output frequency signal.  That is 
not the case, both signals will be time signals.  Maybe I don't 
understand your statement about that.

Third possibility... you are asking for a function that will take a time 
domain signal and turn it into a frequency domain signal?  I don't 
completely understand your post.

-- 

Rick

On Sun, 6 Mar 2016 23:36:39 -0800 (PST), SHREYAS BELGAVE
<spbelgave77@gmail.com> wrote:

>On Monday, February 29, 2016 at 10:34:52 AM UTC+5:30, rickman wrote:
>> On 2/28/2016 11:18 PM, SHREYAS BELGAVE wrote:
>> > Hey,
>> > Have anyone done signal processing on TIVA C launchpad???
>> 
>> I saw your post in c.dsp.  Same question here.  What do you need help 
>> with?  This is just a CM4 and does DSP, sort of.  Not as efficient as a 
>> DSP but can come close for some apps like FIR filters.
>> 
>> -- 
>> 
>> Rick
>
>
>I have got the function for FIR filter from CMSIS library for TIVA C board.
>
>I want to do a high pass filter having cutoff freq 1KHz. 

Digital high pass filters are actually band pass filters, since the
input frequency should be limited below fs/2

>after applying function I am getting signal (i.e. array a[1024]) in frequency domain
>
>so my question is from that how would i know that which a[i] is for the 1Khz freq below 
>which i can suppress the signal and  agin i can do ifft and get the original signal.??

Sounds you have gotten a 1024 FFT of the signal. Knowing the sampling
frequency, it should be easy to select which FFT bins are below 1 kHz
and which are not. Remove the bins that you do not need and perform an
inverse FT to restore the original time domain signal. There are
however various windowing issues in this kind of processing...

If you intend to do FFT/IFFT processing, why are you talking about FIR
filters ?

On Monday, March 7, 2016 at 10:44:52 PM UTC+5:30, rickman wrote:
> On 3/7/2016 2:36 AM, SHREYAS BELGAVE wrote:
> > On Monday, February 29, 2016 at 10:34:52 AM UTC+5:30, rickman wrote:
> >> On 2/28/2016 11:18 PM, SHREYAS BELGAVE wrote:
> >>> Hey, Have anyone done signal processing on TIVA C launchpad???
> >>
> >> I saw your post in c.dsp.  Same question here.  What do you need
> >> help with?  This is just a CM4 and does DSP, sort of.  Not as
> >> efficient as a DSP but can come close for some apps like FIR
> >> filters.
> >>
> >> --
> >>
> >> Rick
> >
> >
> > I have got the function for FIR filter from CMSIS library for TIVA C
> > board.
> >
> > I want to do a high pass filter having cutoff freq 1KHz. after
> > applying function I am getting signal (i.e. array a[1024]) in
> > frequency domain
> >
> > so my question is from that how would i know that which a[i] is for
> > the 1Khz freq below which i can suppress the signal and  agin i can
> > do ifft and get the original signal.??
> 
> If I understand, you are asking how to come up with the coefficients 
> (a[i]) for a high pass filter with a corner frequency of 1 kHz?  Or is 
> a[i] the signal data in which case I don't understand your question.
> 
> Also, part of your post makes it seem like you think a filter will 
> transform the time input signal to an output frequency signal.  That is 
> not the case, both signals will be time signals.  Maybe I don't 
> understand your statement about that.
> 
> Third possibility... you are asking for a function that will take a time 
> domain signal and turn it into a frequency domain signal?  I don't 
> completely understand your post.
> 
> -- 
> 
> Rick

sorry.. I was confused.. now m clear after referring some books.. Yeah my ques was which coefficient represents corner freq of 1 Khz??

On Tuesday, March 8, 2016 at 9:50:56 AM UTC+5:30, upsid...@downunder.com wrote:
> On Sun, 6 Mar 2016 23:36:39 -0800 (PST), SHREYAS BELGAVE
> <spbelgave77@gmail.com> wrote:
> 
> >On Monday, February 29, 2016 at 10:34:52 AM UTC+5:30, rickman wrote:
> >> On 2/28/2016 11:18 PM, SHREYAS BELGAVE wrote:
> >> > Hey,
> >> > Have anyone done signal processing on TIVA C launchpad???
> >> 
> >> I saw your post in c.dsp.  Same question here.  What do you need help 
> >> with?  This is just a CM4 and does DSP, sort of.  Not as efficient as a 
> >> DSP but can come close for some apps like FIR filters.
> >> 
> >> -- 
> >> 
> >> Rick
> >
> >
> >I have got the function for FIR filter from CMSIS library for TIVA C board.
> >
> >I want to do a high pass filter having cutoff freq 1KHz. 
> 
> Digital high pass filters are actually band pass filters, since the
> input frequency should be limited below fs/2
> 
> >after applying function I am getting signal (i.e. array a[1024]) in frequency domain
> >
> >so my question is from that how would i know that which a[i] is for the 1Khz freq below 
> >which i can suppress the signal and  agin i can do ifft and get the original signal.??
> 
> Sounds you have gotten a 1024 FFT of the signal. Knowing the sampling
> frequency, it should be easy to select which FFT bins are below 1 kHz
> and which are not. Remove the bins that you do not need and perform an
> inverse FT to restore the original time domain signal. There are
> however various windowing issues in this kind of processing...
> 
> If you intend to do FFT/IFFT processing, why are you talking about FIR
> filters ?

sorry sir.. I was confused.. now I am clear...

On 3/8/2016 8:11 AM, SHREYAS BELGAVE wrote:
> On Monday, March 7, 2016 at 10:44:52 PM UTC+5:30, rickman wrote:
>> On 3/7/2016 2:36 AM, SHREYAS BELGAVE wrote:
>>> On Monday, February 29, 2016 at 10:34:52 AM UTC+5:30, rickman wrote:
>>>> On 2/28/2016 11:18 PM, SHREYAS BELGAVE wrote:
>>>>> Hey, Have anyone done signal processing on TIVA C launchpad???
>>>>
>>>> I saw your post in c.dsp.  Same question here.  What do you need
>>>> help with?  This is just a CM4 and does DSP, sort of.  Not as
>>>> efficient as a DSP but can come close for some apps like FIR
>>>> filters.
>>>>
>>>> --
>>>>
>>>> Rick
>>>
>>>
>>> I have got the function for FIR filter from CMSIS library for TIVA C
>>> board.
>>>
>>> I want to do a high pass filter having cutoff freq 1KHz. after
>>> applying function I am getting signal (i.e. array a[1024]) in
>>> frequency domain
>>>
>>> so my question is from that how would i know that which a[i] is for
>>> the 1Khz freq below which i can suppress the signal and  agin i can
>>> do ifft and get the original signal.??
>>
>> If I understand, you are asking how to come up with the coefficients
>> (a[i]) for a high pass filter with a corner frequency of 1 kHz?  Or is
>> a[i] the signal data in which case I don't understand your question.
>>
>> Also, part of your post makes it seem like you think a filter will
>> transform the time input signal to an output frequency signal.  That is
>> not the case, both signals will be time signals.  Maybe I don't
>> understand your statement about that.
>>
>> Third possibility... you are asking for a function that will take a time
>> domain signal and turn it into a frequency domain signal?  I don't
>> completely understand your post.
>>
>> --
>>
>> Rick
>
> sorry.. I was confused.. now m clear after referring some books.. Yeah my ques was which coefficient represents corner freq of 1 Khz??

To get that means you need to read more, maybe a *lot* more. 
Calculating the coefficients of a FIR filter is not a horribly complex 
job, but it isn't so easy.  You need to specify the sample rate, the 
filter depth, the corner frequency, the transition band width and the 
stop band attenuation.  You might also want to spec the pass band ripple 
if it is important.  There are programs that will then do the math to 
get the coefficients for you.

-- 

Rick

On Sun, 06 Mar 2016 23:36:39 -0800, SHREYAS BELGAVE wrote:

> On Monday, February 29, 2016 at 10:34:52 AM UTC+5:30, rickman wrote:
>> On 2/28/2016 11:18 PM, SHREYAS BELGAVE wrote:
>> > Hey,
>> > Have anyone done signal processing on TIVA C launchpad???
>> 
>> I saw your post in c.dsp.  Same question here.  What do you need help
>> with?  This is just a CM4 and does DSP, sort of.  Not as efficient as a
>> DSP but can come close for some apps like FIR filters.
>> 
>> --
>> 
>> Rick
> 
> 
> I have got the function for FIR filter from CMSIS library for TIVA C
> board.
> 
> I want to do a high pass filter having cutoff freq 1KHz.
> after applying function I am getting signal (i.e. array a[1024]) in
> frequency domain
> 
> so my question is from that how would i know that which a[i] is for the
> 1Khz freq below which i can suppress the signal and  agin i can do ifft
> and get the original signal.??

I am coming late to this party, but you start by saying you have a 
function for a FIR filter, then you finish with a question that's 
pertinent to doing filtering using FFTs.

They're not the same thing.  Even if you already have your answer, I'm 
curious as to what you're actually dealing with.

-- 
www.wescottdesign.com