On 06/22/2012 12:19 PM, Alexander Olihovik wrote: > So to tune two USRP N210s connected by a MIMO cable, I should set the > command time to be some time spec, and then re-tune both channels to the > same frequency, thus giving them the same phase offset? > > i.e. My code is looking more like:
make sure you you tell the board to get its reference of clock and time source from the mimo cable > self.cmd_time = self.uhd_usrp_source_0.uhd.time_spec_t(.1) careful, make sure that cmd time is a time in the future > self.uhd_usrp_source_0.set_command_time(self.cmd_time) > self.uhd_usrp_source_0.set_center_freq(freq, 0) > self.uhd_usrp_source_0.set_center_freq(freq, 1) > self.uhd_usrp_source_0.clear_command_time() > > > The phases are still off... Is my method incorrect? > Synchronization of device time is separate from synchronizing the phase of the RF frontend. This may be helpful, with code examples for both: http://files.ettus.com/uhd_docs/manual/html/sync.html -Josh > On Fri, Jun 22, 2012 at 1:36 PM, Josh Blum <j...@ettus.com> wrote: > >> >> >> On 06/22/2012 10:18 AM, Alexander Olihovik wrote: >>> For get_time_now(), would I need to swig multi_usrp.hpp? >> >> Everything you see in these headers should be available in python: >> http://gnuradio.org/cgit/gnuradio.git/tree/gr-uhd/include >> >> -josh >> >>> >>> On Fri, Jun 22, 2012 at 12:19 PM, Josh Blum <j...@ettus.com> wrote: >>> >>>> >>>> >>>> On 06/22/2012 07:33 AM, Alexander Olihovik wrote: >>>>> Hi all, >>>>> I'm having some trouble using the C++ UHD API for writing Python code. >>>>> I understand that the code has been SWIG'd from C++ to Python. >>>>> >>>>> >>>>> Specifically, the C++ code I want to convert to Python is: >>>>> --------------------------------------- >>>>> uhd::stream_cmd_t >>>>> stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE); >>>>> stream_cmd.num_samps = samps_to_recv; >>>>> stream_cmd.stream_now = false; >>>>> stream_cmd.time_spec = time_to_recv; >>>>> usrp->issue_stream_cmd(stream_cmd); >>>>> >>>> >>>> Stream command is not swigged because the control of streaming is part >>>> of gnuradio's scheduler. So start() and stop() get automatically called >>>> by the scheduler. For convenience this is a set_command_time() to >>>> control stream_cmd.time_spec. >>>> >>>> Basically, gnuradio is handling the streaming for you. Think block-based >>>> streaming model. >>>> >>>>> uhd::time_spec_t cmd_time = usrp->get_time_now() + >> uhd::time_spec_t(0.1); >>>>> usrp->set_command_time(cmd_time); >>>>> usrp->set_rx_freq(1.03e9, 0/*ch0*/); >>>>> usrp->set_rx_freq(1.03e9, 1/*ch1*/); >>>>> usrp->set_clear_time(); >>>> >>>> This part is swigged. >>>> >>>> -josh >>>> >>>> _______________________________________________ >>>> Discuss-gnuradio mailing list >>>> Discuss-gnuradio@gnu.org >>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>>> >>> >>> >>> >> > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
