Software recommendation

General Discussion
1

Hi All

Just looking for some recommendations for acquiring large chunks (preferably all of the spectrum covered by the limeUSB) of IQ samples. Tools like rx_sdr, rtl_sdr (i know not compatible with lime) only work with a single carrier freq and stated sample rate/bandwidth so the max theoretical captured bandwidth would be 61.44MHz. SoapyPower, rx_power and others are able to do the whole range of the devices capable freq range to obtain power spectrum readings so I’m guessing it should be possible to do just IQ samples for later processing.

Thanks in advance for any guidance P.s I understand the resultant file will be large and take a while to acquire.

2

I have used SdrGlut to capture and play back the 40MHz I/Q data from the LimeSDR mini - so I expect that it can handle the 61.44MHz from the LimeUSB.

Just select “Recording->I/Q Recording” from the pop up menu.

3

Thanks for the reply, the other command line tools I’ve mentioned are able to capture the 61.44MHz also, But I’m looking for something that can do the whole frequency range in one go (100 kHz – 3.8 GHz) or at-least from a couple hundred MHz up to the 3.8GHz. Similar to how rx_power (dosent seem to support the lime) or Soapy_power can capture the power density spectrum within the given freq.

4

I do not know what your problem is - rx_power works Ok with the LimeSDR Mini -

rx_power -f 118M:137M:8k -g 50 -i 10 -d driver=lime -e 1m airband.csv

start0

[WARNING] SoapySSDPEndpoint failed join group udp://[ff02::c]:1900 on en2

setsockopt(IPV6_MULTICAST_IF, 2600:8801:8504:1900:1480:b2ff:9193:afcc) [49: Can’t assign requested address]

[WARNING] SoapySSDPEndpoint failed join group udp://[ff02::c]:1900 on en2

setsockopt(IPV6_MULTICAST_IF, 2600:8801:8504:1900:1962:25fb:4f73:81c3) [49: Can’t assign requested address]

length0 1

Number of frequency hops: 7

Dongle bandwidth: 2714285Hz

Downsampling by: 1x

Cropping by: 0.00%

Total FFT bins: 3584

Logged FFT bins: 3584

FFT bin size: 5301.34Hz

Buffer size: 16384 bytes (3.02ms)

Reporting every 10 seconds

[INFO] Make connection: ‘LimeSDR Mini [USB 2.0] 1D40E98019939A’

[INFO] Reference clock 40.00 MHz

[INFO] Device name: LimeSDR-Mini

[INFO] Reference: 40 MHz

[INFO] LMS7002M register cache: Disabled

Using device LimeSDR-Mini: boardSerialNumber=0x1d40e98019939a firmwareVersion=6 gatewareVersion=1.30 hardwareVersion=2 protocolVersion=1

Found 1 channel(s) :

Channel 0 :

Found 5 antenna(s): NONE LNAH LNAL_NC LNAW Auto

Found 3 gain(s): TIA LNA PGA

Found 2 frequencies: RF BB

Found 63 sample rates: 100000 500000 1000000 1500000 2000000 2500000 3000000 3500000 4000000 4500000 5000000 5500000 6000000 6500000 7000000 7500000 8000000 8500000 9000000 9500000 10000000 10500000 11000000 11500000 12000000 12500000 13000000 13500000 14000000 14500000 15000000 15500000 16000000 16500000 17000000 17500000 18000000 18500000 19000000 19500000 20000000 20500000 21000000 21500000 22000000 22500000 23000000 23500000 24000000 24500000 25000000 25500000 26000000 26500000 27000000 27500000 28000000 28500000 29000000 29500000 30000000 30500000 30720000
…

5

For whatever reason I get a
“Error: bad retune at 119357142 Hz (4 of 3 attempts), r=-1, flags=0 (try increasing -S or -R).”

Whenever trying to use rx_power. However it is fine as for power density spectrum reports, Soapy_power is fine for me.

Its just the wide-band IQ data I am interested in at the moment.

6

Note that there is also a tool which uses LMS API directly and without the need for SoapySDR:

1 Like
7

Hi Andrew

Thanks for that, I have lime-tools installed already and find it very handy, especially the LTEScan. There are also some good packages on F5OEO’s github page for the lime, I’ll link them in below.

I am however looking for a package that can save the IQ data from the full freq range on the lime into a single file. All the packages I come across can either do a single center freq or if its power density related (soapy_power,rx_power, limescan or either of F5OEO’s packages) can do the full range of frequencies.

Would you know of a package that can sweep across the full frequency range and save the IQ data to a file?

F5OEO/

8

sdrTest is a utility that comes with SdrGlut. SdrTest can now be remotely controlled by the control utility - so the scan range in the control02.cpp example could be changed to be the full range of the LimeSDR. You would likely want to give the device some settle time after a frequency change - so in “rxbuffer” you would wait few cycles and then write the I/Q data. A few lines of code is all that would be required. That would get you the full data range. The source code and some video examples -

SdrTest being remotely controlled by the control utility.

sdrTest is a test program for software defined radios.