Hi Yavuz and Arif, Procedure for setting tx gains was broken. So that osmo-trx and all uhd examples (like tx_samples_from_file) didn't set tx gains properly. We have fixed these bugs and now you can update and rebuild uhd (fairwaves/umtrx branch) and osmo-trx (achemeris/umtrx-fixes branch) and these problems should go away.
Thank you for your contribution and reports! 2014-09-22 17:06 GMT+04:00 Yavuz Mert <[email protected]>: > Hi Ivan, > Thank you for the fixes, that definetely works now. > Now in init_gains function, tx_gain_min is set to -18 db and tx_gain_max is > set to 7 db. > Using setTxGain i can set the TX gain to given values between -18 and 7 db, > altough tx_gains[chan] is still returned as -28 db from get_tx_gain(). > I am just wondering are these the correct range values the umtrx board > supports. Umtrx about page states the RF output power as "100mW @ 900MHz, 50mW > @ 1800MHz RF output power". > This is already a valuable improvement and I can live with it, but I am just > wondering about higher output power values. > Also thank you Arif for your contribution. > > yavuz > > On Saturday 20 September 2014 19:55:22 Ivan Kluchnikov wrote: >> Try to clone and compile osmo-trx from: >> git clone git://git.osmocom.org/osmo-trx >> git checkout achemeris/umtrx-fixes >> >> 20 сент. 2014 г. 18:20 пользователь "Arif" <[email protected]> написал: >> > Ivan Kluchnikov <Ivan.Kluchnikov <at> fairwaves.ru> writes: >> > > Hi Yavuz, >> > > Try to use achemeris/umtrx-fixes branch for osmo-trx. >> > > >> > > Also check that you use the latest version of UHD from >> > >> > https://github.com/fairwaves/UHD-Fairwave >> > >> > > If you have old version of FPGA and ZPU, flash current FPGA and ZPU >> > >> > images: http://umtrx.org/hardware/flashing/ >> > >> > > 18 сент. 2014 г. 21:49 пользователь "Arif" <arif.i84 <at> gmail.com> >> > >> > написал:Yavuz Mert <yavuzmertt <at> gmail.com> writes: >> > > > Hi, >> > > > I have a problem setting tx power in osmo-trx. I debugged and found >> > > >> > > that >> > > >> > > > correct gain value is passed to uhd_device::setTxGain. But whatever >> > > >> > > value is >> > > >> > > > set to usrp_dev->set_tx_gain, usrp_dev->get_tx_gain(chan) returns >> > >> > -28 >> > >> > > db. >> > > >> > > > In uhd_device::setTxGain(double db, size_t chan) I put a printf to >> > > >> > > see >> > > >> > > > values. >> > > > >> > > > usrp_dev->set_tx_gain(db, chan); >> > > > tx_gains[chan] = usrp_dev->get_tx_gain(chan); >> > > > printf("Written %f, read %f\n", >> > > >> > > db,tx_gains[chan]);fflush(stdout); >> > > >> > > > Written 21.000000, read -28.000000 >> > > > Written 11.000000, read -28.000000 >> > > > Written -35.000000, read -28.000000 >> > > > >> > > > But despite the read values, actually the power is somewhat changed. >> > >> > I >> > >> > > plugged >> > > >> > > > TX1 to spectrum analyzer and set TX gain from -35 to 21 in 2 db >> > >> > steps. >> > >> > > Until >> > > >> > > > -5 db the signal gradually increases, but from -5db to -3db it drops >> > > >> > > down to >> > > >> > > > lowest. Is there something I should pay attention while using higher >> > > >> > > gain >> > > >> > > > values. Meanwhile I do not play with RX gain or noise level, leave >> > > >> > > them at >> > > >> > > > default values. >> > > > >> > > > thanks >> > > > yavuz >> > > >> > > Hi, >> > > i am facing the same issue, and have spend the whole day to find that >> > > tx_gain value is not set no matter what. the output signal only >> > > registers maximum of 1.6 dBm on watt-meter. >> > > Temperature is not high so i doubt temperature is a problem. may be >> > >> > its >> > >> > > related to uhd driver? or tx_gain values not written to eeprom. >> > > i might be missing some configuration option or trick. any help is >> > >> > much >> > >> > > appreciated, >> > > thanks, >> > > arif >> > >> > Hello Ivan, >> > >> > thank you replying cause i'm having same problem. i flashed current >> > version of ZPU and FPGA images. >> > >> > then again i ran the test using following command >> > >> > tx_samples_from_file --rate 1083333 --freq 9550e5 --bw 1500000 --file >> > multiframe_norm.dat --type float --loop--gain 18 --subdev A:0 >> > >> > but still i see the same actual tx gain: -28.0000 dB.. >> > >> > i couldn't find the achemeris/umtrx-fixes branch for osmo-trx. Further i >> > have cloned the latest code from uhd-fairwaves as well. >> > >> > thanks, >> > arif > > -- Regards, Ivan Kluchnikov. http://fairwaves.ru
