Re: [Discuss-gnuradio] Using the UHD API for Python Programming

[Alexander Olihovik]

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:
self.cmd_time = self.uhd_usrp_source_0.uhd.time_spec_t(.1)
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?

On Fri, Jun 22, 2012 at 1:36 PM, Josh Blum <address@hidden> 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 <address@hidden> 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
>> address@hidden
>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>
>
>
>