# Grc-mimo setup **URL:** \ **Category:** GNU Radio\ **Created:** [May 15, 2014, 3:00pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160 "2014-05-15T15:00:26Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Post date:** [May 15, 2014, 3:00pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160/1 "2014-05-15T15:00:26Z")
Hello all: Environment: 2 usrp N210,mimo cable(they connect with each other and share the Ethernet) ``` And i use the gnuradio companion to set up a very simple ``` example.And the example is attached on the email.And I run this simple example,an error comes: RuntimeError: ValueError: Could not resolve device hint “” to a single device. ``` And ping 192.168.10.2 and ping 192.168.10.3,it's all ok. Can someone help me to solve it?Thank you very much. ``` Best regards ---
**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\ **Post date:** [May 15, 2014, 3:03pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160/2 "2014-05-15T15:03:31Z")
Your device hint in the ‘Device Addr’ section of the ‘UHD Source’ block should be “addr=192.168.10.2” and in a separate ‘UHD source’ block the “Device Addr” should be “addr=192.168.10.3” Mike – Mike J. M0MIK BSc MIET Ettus R. Technical Support Email: removed\_email\_address@domain.invalid Web: [http://ettus.com](http://ettus.com) ---
**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\ **Post date:** [May 15, 2014, 3:10pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160/3 "2014-05-15T15:10:18Z")
Hi Mike Thank you for your reply. Now I change the addr but a new error comes: thread[thread-per-block[1]: \]: LookupError: KeyError: Cannot find an item size: thread[thread-per-block[2]: \]: LookupError: KeyError: Cannot find an item size: Can you help me?Thank you. Best regrads At 2014-05-15 20:48:44,“Mike J.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Your device hint in the ‘Device Addr’ section of the ‘UHD Source’ block should be “addr=192.168.10.2” and in a separate ‘UHD source’ block the “Device Addr” should be “addr=192.168.10.3” Mike – Mike J. M0MIK BSc MIET Ettus R. Technical Support Email: removed\_email\_address@domain.invalid Web: [http://ettus.com](http://ettus.com) On Thu, May 15, 2014 at 1:39 PM, xianda [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Hello all: Environment: 2 usrp N210,mimo cable(they connect with each other and share the Ethernet) ``` And i use the gnuradio companion to set up a very simple ``` example.And the example is attached on the email.And I run this simple example,an error comes: RuntimeError: ValueError: Could not resolve device hint “” to a single device. ``` And ping 192.168.10.2 and ping 192.168.10.3,it's all ok. Can someone help me to solve it?Thank you very much. ``` Best regards ---
**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\ **Post date:** [May 15, 2014, 3:10pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160/4 "2014-05-15T15:10:18Z")
A sample rate of 32e3 is very low. I suggest trying with a minimum sample rate of 100e6/128 (always divide the N210’s master clock rate by an even number to use as a sample rate) which is 781250. Mike – Mike J. M0MIK BSc MIET Ettus R. Technical Support Email: removed\_email\_address@domain.invalid Web: [http://ettus.com](http://ettus.com) ---
**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\ **Post date:** [May 15, 2014, 3:46pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160/5 "2014-05-15T15:46:01Z")
Hello Thank you so much. 1.And i set the wire format as Complex int16.And it run.Thank you again.I’m so happy.This device bring us so many happy. But what do you mean “git pull”?Sorry for my poor english. Can you tell me what command i should type into the shell?And then rebuild UHD. 2.Another question.If i write the c++ documend in the uhd,and one document is using for transmit and the other one is using for receive.And i puzzled.In the gnuradio companion mode we can put the source and sink into the same document.But now two c++ document and i want to run them at the same time as in the gnuradio mode.How can i do it? Thank you again for your quick reply. Best regards ---
**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\ **Post date:** [May 15, 2014, 3:11pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160/6 "2014-05-15T15:11:32Z")
This was a UHD bug we fixed a couple of weeks back. If you’re using git/master, you can just git pull, rebuild UHD and it will work. Otherwise, you can set otw\_format=sc16 in the streamer args and it will solve the problem as well. Cheers, M ---
**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\ **Post date:** [May 15, 2014, 4:09pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160/7 "2014-05-15T16:09:25Z")
Hi Mike Thank you for your patience.Thanks again. At 2014-05-15 22:01:00,“Mike J.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: If you built GNU Radio and UHD using pybombs then you can just run: ./pybombs update gnuradio Alternatively, if you build manually you can go into the ‘uhd/host/build’ directory and run: git pull cmake …/ make sudo make install Mike – Mike J. M0MIK BSc MIET Email: removed\_email\_address@domain.invalid Web: [http://scanoo.com](http://scanoo.com) On Thu, May 15, 2014 at 2:29 PM, xianda [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Hello Thank you so much. 1.And i set the wire format as Complex int16.And it run.Thank you again.I’m so happy.This device bring us so many happy. But what do you mean “git pull”?Sorry for my poor english. Can you tell me what command i should type into the shell?And then rebuild UHD. 2.Another question.If i write the c++ documend in the uhd,and one document is using for transmit and the other one is using for receive.And i puzzled.In the gnuradio companion mode we can put the source and sink into the same document.But now two c++ document and i want to run them at the same time as in the gnuradio mode.How can i do it? Thank you again for your quick reply. Best regards ---
**Author:** ![xianda](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/b38774/32.png) [@xianda](https://www.ruby-forum.com/u/xianda)\ **Post date:** [May 15, 2014, 4:03pm UTC](https://www.ruby-forum.com/t/grc-mimo-setup/241160/8 "2014-05-15T16:03:15Z")
If you built GNU Radio and UHD using pybombs then you can just run: ./pybombs update gnuradio Alternatively, if you build manually you can go into the ‘uhd/host/build’ directory and run: git pull cmake …/ make sudo make install Mike – Mike J. M0MIK BSc MIET Email: removed\_email\_address@domain.invalid Web: [http://scanoo.com](http://scanoo.com)