Hi Dave, you shouldn't be modifying the python files before you understand what they do exactly. Please revert your edits, because it will be impossible to help you if you don't use the same scripts as we do, obviously. We've talked about this[1].
So: > Sender : benchmark_tx.py -f 2.435G -r 250k > Receiver : benchmark_rx.py -f 2.435G That's wrong! Now, your transmitter sends 250,000 bits per second, but your receiver expects 100.000 (the default value, which doesn't work with your hardware), so that's not good. Use the same setting for both benchmark_tx and benchmark_rx. > So all you say is I need to change and play with the sampling rates > and --tx-amplitude until the received packet becomes 'n_rcvd=1' No. RF is not "hey, there's this correct setting, let's apply it everywhere"; you'll have to figure out which combination settings work best. Generally, I'd leave the --tx-amplitude untouched, because 0.25 is a sane value for the digital samples; what you want is analog gain, not digital scaling. You should really set a TX gain and a RX gain. Try around with a few different gain settings for RX and TX gain -- a good approach would be to set something like 25 dB TX gain, and around 50 dB RX gain, if you place your TX and RX antennas far enough from each other. Notice that I'm assuming you're using antennas, and no direct connection! If you're using a direct cable between TX and RX, please use an attenuator, because you might otherwise damage your hardware. To find out how to change the gains, please read the output of benchmark_tx.py --help and of benchmark_rx.py --help Best regards, Marcus [1] http://lists.gnu.org/archive/html/discuss-gnuradio/2015-09/msg00124.html On 21.09.2015 16:48, Rama V wrote: > > I have tried the following commands in the terminal > > Sender : benchmark_tx.py -f 2.435G -r 250k > Receiver : benchmark_rx.py -f 2.435G > > But the data packets are not being sent correctly. I have been > receiving the packets as ok=false. I have tried modifying benchmark > python scripts. Can I do the modification of those scripts or > evrything needs to be given in the command line. Please excuse me as I > am slightly unable to understand. Thanks > > Regards, > Dave > > On Sep 18, 2015 2:21 PM, "Rama V" <ramav...@gmail.com > <mailto:ramav...@gmail.com>> wrote: > > Thanks for the reply Michael. I will look into that as you have > advised. So all you say is I need to change and play with the > sampling rates and --tx-amplitude until the received packet > becomes 'n_rcvd=1' and CRC check changes to 'ok=true' from the > narrowband folder? > > Regards, > Dave > > On Fri, Sep 18, 2015 at 12:40 PM, Michael Dickens > <michael.dick...@ettus.com <mailto:michael.dick...@ettus.com>> wrote: > > Hi Dave - I'm thinking that you are confusing > "--samples-per-symbol" for the sample rate. I think the option > you're looking for is "-r". Look at the "--help" for those > examples when you get a chance. - MLD > > On Thu, Sep 17, 2015, at 02:01 PM, Rama V wrote: >> >> Thank you very much Michael. I will follow up on your advice. >> I am sorry that I wasn't able to understand some parts in GNU >> RADIO and didn't specify enough information. Regarding the >> question, I have been doing the benchmark in the digital/ >> narrowband/ folder. The exact commands I have been working on are >> >> Sender: benchmark_tx.py -f 2.435G --tx-gain 25 >> --samples-per-symbol 250000 >> >> Receiver: benchmark_rx.py -f 2.435G >> >> When I give 250kS/s, my laptop freezes. USRP is XCVR2450. So >> I started to give less Samples like 50kS/s so that they >> communicate with each other without errors. But I couldn't >> figure out the solution to that. So I just have a doubt >> whether I need to modify benchmark scripts or is it enough >> for the parameters I give in the command line. Thanks for the >> help. Please advice >> > > > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
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