Gr-limesdr problems with LimeSDR-USB

#1

Hello everyone, I have a LimeSDR-USB and a LimeSDR-Mini. I am running Ubuntu 18.04, with Gnu Radio, LimeSuite, gr-osmosdr and gr-limesdr installed via pybombs.

Both the boards are recognized by LimeUtil and they both pass the LimeQuickTest. When I try to use the LimeSuite Source in Gnu Radio, I can only get output with the LimeSDR-Mini, and not the LimeSDR-USB.
When using osmocom source, I see output from both of the boards.
Here is the output from the flowgraph:

LimeSDR-USB:

LimeSuite Source (RX) info

##################
Connecting to device
##################
Devices found: 1
##################
Device list:
Nr.:|0|device:|LimeSDR-USB, media=USB 3.0, module=FX3, addr=1d50:6108, serial=0009072C00D6172C
##################
INFO: device_handler::open_device(): no serial number. Using first device in the list. Use “LimeUtil --find” in terminal to find prefered device serial.
##################
Device number 0 from the list is used.
Reference clock 30.72 MHz
##################

INFO: device_handler::enable_channels(): SISO CH0 set for device number 0.
INFO: device_handler::set_samp_rate(): set sampling rate: 2 MS/s.
INFO: device_handler::set_rf_freq(): RF frequency set [RX]: 100.1 MHz.
INFO: device_handler::set_analog_filter(): RX LPF configured
INFO: device_handler::set_digital_filter(): digital filter CH0 [RX]: 0.1 MHz.
INFO: device_handler::set_gain(): set gain [RX] CH0: 60 dB.
INFO: device_handler::set_antenna(): CH0 antenna set [RX]: LNAL.
gr::log :INFO: audio source - Audio sink arch: alsa
INFO: source_impl::init_stream(): source channel 0 (device nr. 0) stream setup done.

LimeSDR-Mini:
LimeSuite Source (RX) info

##################
Connecting to device
##################
Devices found: 1
##################
Device list:
Nr.:|0|device:|LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1D3AD56D717CE1
##################
INFO: device_handler::open_device(): no serial number. Using first device in the list. Use “LimeUtil --find” in terminal to find prefered device serial.
##################
Device number 0 from the list is used.
Reference clock 40.00 MHz
##################

INFO: device_handler::enable_channels(): SISO CH0 set for device number 0.
INFO: device_handler::set_samp_rate(): set sampling rate: 2 MS/s.
INFO: device_handler::set_rf_freq(): Selected RX path: LNAW
RF frequency set [RX]: 100.1 MHz.
INFO: device_handler::set_analog_filter(): RX LPF configured
INFO: device_handler::set_digital_filter(): digital filter CH0 [RX]: 0.1 MHz.
INFO: device_handler::set_gain(): set gain [RX] CH0: 60 dB.
INFO: device_handler::set_antenna(): Selected RX path: LNAW
CH0 antenna set [RX]: LNAW.
gr::log :INFO: audio source - Audio sink arch: alsa
INFO: source_impl::init_stream(): source channel 0 (device nr. 0) stream setup done.

Here are screenshots when using the FM-reciever in the gr-limesdr examples
LimeSDR-USB:


LimeSDR-Mini:

#2

Try to update your LimeSuite packages. There was an issue when LimeSuite didn’t return any samples when sampling rate was < 2.5 MS/s on LimeSDR-USB boards. https://github.com/myriadrf/gr-limesdr/issues/41

#3

alright, I will try to update the packages and see if it works.

One more thing, I tried using LimeSDR-USB to receive a satellite’s beacon, but I could not even see the signal, but when using a Funcube Dongle or even a RTL-SDR, I could clearly see the beacon. I later did some testing (using osmocom source and GQRX so maybe that is the problem), transmitting from a signal generator at UHF, I had the LNAL antenna selected, with the maximum RF gain. The signal was clearly visible on HDSDR with Funcube Dongle, and also visible on GQRX and Gnu Radio when using a RTL-SDR (osmocom source). How is this possible? Can it be because I am using the osmocom source?

#4

Ok, I updated LimeSuite and it works now. About the other issue, I did some testing, and it seems like my LimeSDR-USB is defective, I compared its performance to my LimeSDR-Mini and some other SDR’s, and it performed the worst, and a signal that was easily detected on all the other SDR’S, was not detected with the LimeSDR-USB. I will post my test and results in another topic later.

#5

Hi there.
I new to SDR but have technical background.
I got the same problems. None of the examples on GNU radio (running on Windows) works. I simply get no output from the LimeSDR block. I downloaded and installed the software this week. After reading this post, I tried 3M sample rates - works.
I also tested SDRAngel, but I got lousy RX sensitivity and crosstalk (Rx center frequency in FFT screen). After lots of trying and testing, I started LimeSuite and reset the device to defaults. After that I got much better snsitivity. This stays that way.
As many beginners, I did the self test at first. I think, that this screws something in the device which is not reset by other tools…

#6

@Gwaihir - Gwaihir,

Welcome to the forum…! Actually, you should get a gold star for noticing that issue and knowing how to reset the Lime to make it work again. It’s a common issue that there are apps out there that have a tendency to set the Lime’s parameters improperly and those same parameters are often ‘overlayed’ with another app that uses them differently - hence the reason you found less than desirable performance after using the test app, tried to use 'Angel and then found that using LimeSuite remedies the issue. Again, it’s a pretty common issue if you know about it, and for a true beginner it’s a plus you found this at the outset. I do wish app developers would reset the Lime parameters to a known useful state before they close the app such that the user doesn’t think something has gone wrong in the hardware.

@andrewback @Zack - See my above comment on apps having issues with the Lime and degraded performance - - I know this isn’t LMS’s issue, but there should be a ‘best practices for development’ paper or posting used when optimizing the Lime for use with their app. There should be a ‘factory default’ settings overlay that the developers can send to the Lime to make sure that when the next app uses it, it won’t be impacted by the prior app’s settings - that the Lime would be like it came from the factory.

@Gwaihir - Pertaining to your question on the issue of GRC’s LimeSDR blocks, please make sure your Lime is running the latest gateware and that the approved installation for Lime was applied to your GRC install - - hopefully you used this installation procedure:

https://wiki.myriadrf.org/Gr-limesdr_Plugin_for_GNURadio

Let us know your progress and again, welcome to the LimeSDR forum…!

73 de Marty, KN0CK