Re: [Discuss-gnuradio] Rate of uhd_source

On Mon, 7 May 2012 10:50:18 -0300, Loic Danceg wrote:

Hi everybody,

I try to use the function uhd.usrp_source.

It works well with the default rate

        parser.add_option("-s", "--samp-rate", type="eng_float", default=1e6,
                          help="set sample rate (bandwidth) [default=%default]")

But i would like to have a better rate (1e9), and if i change that, it didn't works.
Someone know why?

Thank you a lot!

        self.u = uhd.usrp_source(device_addr=options.args,
                                 stream_args=uhd.stream_args('fc32'))

        # Set the subdevice spec
        if(options.spec):
            self.u.set_subdev_spec(options.spec, 0)

        self.u.set_samp_rate(options.samp_rate)

Requested sample rates from UHD hardware must be proper divisors of the master sampling rate on the hardware.  For USRP1/B100/E100, that's 64Msps, and for N2XX it's 100Msps.

Typically, sample rates between master_rate/4 to master_rate/512 are supported.

A sample rate of 1e9 is not a valid sample rate--and seriously 1 Gigasample/second?  You really expected your computer to keep up to 1 GigaSample/second?