Re: [Discuss-gnuradio] Trouble on top block lock/disconnect/connect/unlock with usrp2

[ILKYOUNG KWOUN]

Eric,

Thank you for your prompt comment.  :-)

My mistake on the previous explanation. Actually, what I want to do is not simply change the filter coefficients but to change the entire filter.

To prevent the sample value converge to '0' by the hardware decimation filters in FPGA(I posted once asking this matter before), I fixed the usrp2 decimation rate to '4' and implemented software decimation filters. 
The filter frequency band(passband cut-off, stopband cut-off) and number of decimation would dynamically changes. So, my idea is to re-generate the filter every time the user command changes. To do this, I thought I had to perform the 'lock/disconnect/changing_filter(s)/connect/unlock' procedure. (The filter(s) shall be between 'self.u' and 'self.s2v' in my previous post)

1. Am I on the right track? Or, still can I just change the filter coeffs. and decimation rate at runtime? 

2. Filter coeffs. and decimation rate are two parameters of gr.fir_filter_ccf() function to generate a decimation filter. What function can I use to change the parameters of running filter instance?

3. This is an off topic, but I wonder if gnuraio.org server is still down. I could not have connected the site since evening of the day before yesterday.

Regards,
ILKYOUNG.

2010/1/3 Eric Blossom <address@hidden>

On Sun, Jan 03, 2010 at 02:41:35AM +0900, ILKYOUNG KWOUN wrote:
> Happy New Year! folks,
>
> I need to dynamically change software filter coefficient according to user
> command while the program is running.
> So, I made a test program similar to the following.

There's no reason to do all this lock/disconnect/connect/unlock stuff
if all you want to do is change the filter coefficients.

Just set them.

Eric