I have looked at that file and you have made gain, frequency, and LO offset variables and then you send messages every 2 secs. When I run the file, I try to change the frequency from 2.4 to 2.5 G using the glider in the GUI. It should change the value of the variable which should be reflected in the actual center frequency. However, I do not see the frequency changing after 2 secs in the Frequency Sink Plot. Is that the right way to change the value of the variable ?
On Fri, Feb 24, 2017 at 11:06 AM, Derek Kozel <derek.ko...@ettus.com> wrote: > Hello, > > For every message which you send UHD would change the gain once. So in > order to alternate every 100ms you would send 10 messages a second, > advancing the timestamp value by 100ms each time. The example I linked to > shows the frequency and gain being changed every two seconds. You'll just > need to alter the arguments to have it alternate the gain. > > Regards, > Derek > > On Fri, Feb 24, 2017 at 8:52 AM, Qurat-Ul-Ann Akbar < > quratulannakbar2...@u.northwestern.edu> wrote: > >> Also I want to keep doing this in a loop (the values keep alternating >> after an interval). Will it be possible through the command port interface ? >> >> >> On Fri, Feb 24, 2017 at 9:17 AM, Qurat-Ul-Ann Akbar < >> quratulannakbar2...@u.northwestern.edu> wrote: >> >>> Hi Derek, >>> >>> Thank you for your email. If you could find that file it would be really >>> helpful. What I want to do is to alternate between two or more values of >>> gain after specific intervals. Can I alternate like this using the command >>> port interface? How will the block USRP sink block know which value to use >>> ? Can you kindly explain that a bit. >>> >>> >>> >>> On Thu, Feb 23, 2017 at 4:23 PM, Derek Kozel <derek.ko...@ettus.com> >>> wrote: >>> >>>> Hello, >>>> >>>> The command port interface can be used to change the gain value. There >>>> is an example of creating messages for tuning included in gr-uhd. >>>> https://github.com/gnuradio/gnuradio/blob/master/gr-uhd/exam >>>> ples/grc/uhd_msg_tune.grc >>>> >>>> I've used a function probe to generate coarsely timed "tick" messages >>>> to a custom python block which is correctly formatting the messages before. >>>> Unfortunately I cannot find that GRC file at the moment. The function probe >>>> will run at an approximate interval dependent on your system and GNU >>>> Radio's scheduler. If you don't need exact timing then just use the gain >>>> message and function probe, if you do need exact timing include both time >>>> and gain values in the pmt command message then the gain will be applied at >>>> the specific time based on the radio timestamp. Set the Sync setting to >>>> unknown_pps, which will set the radio timestamp to 0 when the flowgraph >>>> starts, and set the initial timestamp for the command port message to a >>>> second or two in the future to account for the startup time of the >>>> flowgraph. >>>> >>>> Regards, >>>> Derek >>>> >>>> On Thu, Feb 23, 2017 at 1:36 PM, Qurat-Ul-Ann Akbar < >>>> quratulannakbar2...@u.northwestern.edu> wrote: >>>> >>>>> Hi, >>>>> >>>>> I want to alternate the gain of the USRP between two values after a >>>>> certain period of time. For example after 100 ms it should go from A to B >>>>> and after another 100 ms the value should go from B to A and so on. >>>>> >>>>> Is there an easy way of doing this in the GNU Radio companion or would >>>>> I need to start a timer in python and put an IF condition to keep changing >>>>> the value? Can I do this somehow using the probe block? >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> Discuss-gnuradio mailing list >>>>> Discuss-gnuradio@gnu.org >>>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>>>> >>>>> >>>> >>> >> >
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