Hi, all,
I have a E312 device and I just find that the tuning speed of E312 is very slow
(\~150ms) for each tuning. Thus I would like to modify the underlying tuning
source code in the uhd software architecture.
Here is what I found:
I first create a multi_usrp object:
uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(device_args);
then I tune the usrp by running a loop:
int count = 200;\
for(int a = 0; a < count; a++) {\
uhd::tune_request_t tune_request(600e6 + a\*10e6);\
\
usrp->set_rx_freq(tune_request, 0);\
usrp->set_tx_freq(tune_request, 0);\
}
Basically, the loop tunes the frequency from 600MHz to 2.6 GHz with a step size
of 10 MHz. The 200 tunings take 52 seconds, which is pretty slow.
Thus, I traced the call stack from usrp->set_rx_freq(tune_request, 0). Here is
what I found:
1. usrp->set_rx_freq(tune_request, 0); calls the method set_tx_frequency() in
uhd/host/lib/usrp/dboard/e3xx/e3xx_radio_control_impl.cpp
2. then the method set_tx_frequency() in
uhd/host/lib/usrp/dboard/e3xx/e3xx_radio_control_impl.cpp calls the tune()
method in uhd/host/lib/usrp/dboard/e3xx/e3xx_ad9361_iface.cpp
3. then the tune() method in
uhd/host/lib/usrp/dboard/e3xx/e3xx_ad9361_iface.cpp calls the method
set_tx_frequency() in uhd/host/lib/rfnoc/radio_control_impl.cpp.
The conclusion I have reached so far is the underlying tuning method is in
uhd/host/lib/rfnoc/radio_control_impl.cpp:
double radio_control_impl::set_tx_frequency(const double freq, const size_t
chan)\
{\
std::lock_guard<std::mutex> l(_cache_mutex);\
return _tx_freq\[chan\] = freq;\
}
Then I just got stuck here, what is the _tx_freq\[chan\] ? I just can not find
more.
What I want to do is to modify the underlying ad9361 driver, so that when
tuning a frequency, I can bypass the calibration in the ad9361 to speed up the
tuning speed.
Can anyone point me to 1.where I can find the source code for tuning for the
E312 with uhd 4.0 or 2. how to use mpm to get low-level access to ad9361 so
that I can write my own tuning method for ad9361 ?
Thanks,
Yan
_______________________________________________
USRP-users mailing list -- [email protected]
To unsubscribe send an email to [email protected]
