On Thu, 2011-07-21 at 11:28 -0400, Yan Nie wrote: > > well, sizeof(complex<short>) == sizeof(float), which means gnuradio will > > let you connect those blocks, but that definitively wont work. > > > > For the UHD source, use COMPLEX_FLOAT32. For the FIR filter, use complex > > input. > > > > gnuradio-companion might help you a lot: > > http://en.wikipedia.org/wiki/GNU_Radio_Companion > > I appreciate your reply. I changed the io type for UHD source and type of the > input for FIR filter, and got them matched, which leads the final result to > the right direction, but still not quite right. It is just a simple trial to > detect a 100kHz sinusoid signal and down convert the frequency to 1kHz. I am > expecting a 1kHz sinusoid wave from plotting, but it only gave some irregular > oscillation at the beginning. I am still confused that what could be the > problem here? > > u2=uhd.single_usrp_source(device_addr="addr=192.168.10.2",io_type=uhd.io_type_t.COMPLEX_FLOAT32,num_channels=1) > u2.set_samp_rate(250e3) > treq = uhd.tune_request(freq) > tr = u2.set_center_freq(self.treq) > decim_coeffs = gr.firdes.low_pass(1.0, > 5e3, #sampling frequency > 2e3, #cutoff frequency > .1e3, > gr.firdes.WIN_BLACKMAN) > decim_filter = gr.fir_filter_ccf(1,decim_coeffs) > dst = gr.file_sink(gr.sizeof_gr_complex,filename) > connect(self._u2, self.decim_filter,self.dst)
Yan, Why is your filter sampling frequency 5kHz, when your USRP sample rate is 250kHz? --n > > > Thank you so much for your help > > with thanks, > Yan > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
