Re: [Discuss-gnuradio] halfband in CVS

[Lamar Owen]

On Monday 24 October 2005 22:19, Eric Blossom wrote:
> Matt's been hard at work on the halfband filter for the FPGA, and it's
> in pretty good shape.  As long as you're not using a decimation factor
> of 10, everything looks good.  The FPGA code along with the relevant
> host side mods are checked in.

Very cool.

> Also, there's some work-in-progress to support inbound 8-bit samples
> across the USB.  The interfaces are in (u.set_format(...)), but it's
> not all sorted out yet.

Since it's not all sorted out, any way possible that an arbitrary 8-bit window 
out of the 12 bit gamut be available?  That is, will the API allow me to set 
the LSB of the 8 bit samples to be at any of bits 0, 1, 2, 3, or 4?  Kindof a 
crude gain control and noise reduction in one fell swoop.  This is extremely 
cool; I can double my pulsar system's bandwidth easily with this.

I will attempt to try this out tomorrow on the PARI pulsar system, since it is 
currently tracking CVS, and the FFT curves are well characterized against the 
passband of the frontend there, and I know the hot-cold difference, passband 
shape, etc really well at this point. 
-- 
Lamar Owen
Director of Information Technology
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC  28772
(828)862-5554
www.pari.edu