Use the advanced tuning parameters. http://files.ettus.com/uhd_docs/manual/html/general.html#tuning-notes
2011/12/12 osama mohamed <osama_valencia...@hotmail.com>: > > >> Date: Mon, 12 Dec 2011 08:07:57 -0800 >> From: j...@ettus.com >> To: osama_valencia...@hotmail.com; usrp-us...@lists.ettus.com >> Subject: Re: [Discuss-gnuradio] USRP1 questions > >> >> >> >> On 12/12/2011 01:52 AM, osama mohamed wrote: >> > >> > hi all, >> > i am using USRP1 with basic tx and rx boards and i have been suffering >> > some problems recently so i hope you could answer the following >> > questions(even if not all of them) >> > >> > Q1: >> > when i run the examples tx_timed_samples.cpp and tx_burst.cpp i don't >> > get any output i tried various sampling rates and amplitudes but they >> > still didn't produce any output if there is a certain configuration >> > (i.e. sampling rate and amplitude) that works kindly inform me also i >> > would like to know the output i am expected to see? >> > >> > >> >> Those are examples apps to demonstrate API usage. See tx waveforms or tx >> samples from file for examples that transmit. >> >> > Q2: i would like to tx a signal by setting the NCO frequency on the >> > codec chip through the class codec_ctrl instead of using the PLL, is >> > this doable or not and ,if yes should i use the class multi_usrp or i >> > have to jump to the lower level class usrp1_impl? >> > >> > >> If you have basic TX and usrp1, the only frequency translation occurs in >> the codec. There is no PLL. >> >> > Q3: can i use the low level class usrp1_impl to do the same >> > functions of the examples tx_timed_samples.cpp and tx_burst.cpp >> > through setting the frequency tuning word of the codec through the class >> > codec_ctrl ? >> > >> > >> >> The implementation is not exposed. You will need some "creative" coding >> if you want to access the internal objects. >> >> What do you think is missing in the "multi_usrp" wrapper? >> >> > Q4: as i understand from the constructor of the class usrp1_impl the >> > sampling rates of the tx path are automatically detected and assigned >> > through this constructor is this true or i have to set them through a >> > certian function? >> > >> > >> >> You should manually set the desired sample rate through the API. >> See >> >> http://files.ettus.com/uhd_docs/doxygen/html/classuhd_1_1usrp_1_1multi__usrp.html#ab8bc17744d3ee94b7c5cdcb75457bd6b >> >> -Josh > > > > > > hi Josh, > thanks a lot for your support. > > the problem with the "multi_usrp" wrapper is that if i use another board for > example WBX it will generate the desired frequency through the PLL except > > for frequencies less than the minimum threshold (which is as i remember 62 > MHZ for WBX) so in the later case it will set the PLL to the minimum > > frequency (i.e. 62 MHZ) and will compensate the difference through the NCO > (as i understand) > > i want to do the same by myself even if the target frequency is in the > supported range by the WBX (for example : i want to set the PLL to 935 MHZ > and > > tune the NCO by +or - 44MHZ to get the up and down link ranges of the GSM > system ), the reason for using the NCO instead of the PLL is that the NCO > > tuning is instantaneous unlike that of the PLL which takes about 200 micro > secs > > i think this request is not supported by the "multi_usrp" wrapper ?? > > thanks, > osama riad > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
