Hi, Is there an example where two usrp sources are used to sample from two daughtercards simultaneously? Or is this even possible? Best Regards, juha
on 2008-10-12 22:25
on 2008-10-13 14:43
RTFM. gnuradio-examples/python/multi-antenna/multi_file.py Even four channels seems to be possible, using BasicRX, and special firmware. Has anyone successfully done multi_usrp with four channels per USRP? juha
on 2013-12-04 11:06
On 12/03/2013 12:00 PM, Nemanja Savic wrote: > ), > ) > > You should probably start with a GRC flow-graph with a single UHD USRP source, with two channels being what you want, and look at the generated Python code. -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org
on 2013-12-04 11:12
Thank you Marcus again, I changed device address, in both places, but the same problem appears. I see that it loads now 4rx image, but the problem remains. self.uhd_usrp_source_1 = uhd.usrp_source( device_addr="fpga=usrp1_fpga_4rx.rbf", stream_args=uhd.stream_args( cpu_format="fc32", channels=range(1), ), )
on 2013-12-04 11:17
I did following: I made simple flow graph and used USRP source first with two channels and LFTX mboard. But the follwong error occurs: File "/home/savi_ne/work/gnuradio/GRC/top_block.py", line 105, in __init__ self.uhd_usrp_source_0_0_1.set_center_freq(433900000, 1) File "/usr/local/lib64/python2.6/site-packages/gnuradio/uhd/uhd_swig.py", line 1872, in set_center_freq return _uhd_swig.uhd_usrp_source_sptr_set_center_freq(self, *args) RuntimeError: vector::_M_range_check When I tried with setting two mboards, with LFTX A channel subdevice in the first channel (B:A option_ and WBX on the second channel I get following error: File "./top_block.py", line 101, in __init__ self.uhd_usrp_source_0_0_1.set_subdev_spec("A:0", 1) File "/usr/local/lib64/python2.6/site-packages/gnuradio/uhd/uhd_swig.py", line 1831, in set_subdev_spec return _uhd_swig.uhd_usrp_source_sptr_set_subdev_spec(self, *args, **kwargs) RuntimeError: vector::_M_range_check And as far as I have seen GRC doesn't put anything in the field device_addr for changing FPGA image.
on 2013-12-04 12:22
Everything is OK, I have just put "B:A A:0" in the subdevice field.
on 2013-12-04 12:54
So everything worked fine except I got the following warning: UHD Warning: Mixing real and quadrature rx subdevices is not supported. The Q input to the real source(s) will be non-zero. Which is probably due to my wish to use WBX with IQ and only one channel from LFTX. Is there any way to overcome this problem, and is there any explanation why this happens, cause when I use only LFTX, and particularly one channel (let say I), the Q is automatically produced within FPGA and I finally get complex baseband. Havung this in mind, why would UHD complain about real and wuadrature subdevices. Cheers, Nemanja