> 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) Thank you so much for your help with thanks, Yan _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
