LimeMini Problems

#1

So I’ve been trying different things in my limited spare time to see if I can get my LimeMini to work. It doesn’t seem to be able to receive anything.

On a whim today I took it out of the case and looked it over and it looks like some of the components are touching that shouldn’t be. Does anyone know if those caps at the bottom of this picture are supposed to be like that? Specifically C181 & C176 and C182 & C177.

LimeSDR mini: No reception at all
#2

You could always check the layout files to confirm if the nets are different, but looks like it could be an issue.

I also see some issues left of the R49 label under the BGA.

#3

i hope its ok because mine is just like yours and i been using it for about 24hrs
https://drive.google.com/file/d/1ZV28uJY4qBYsi0WbV6VRjySc9O7pbhRE/view?usp=sharing

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#4

If you’ve been using it without problems it’s most likely just the ground side of the capacitors touching… I hope :slight_smile:

I haven’t gotten the LimeMini working in GQRX yet but I found the “Antenna” setting in CubicSDR and how it works in that program. I hope to figure out GQRX soon.

So I think this might just have been me worrying for no reason.

#5

Received mine today. Same issue. I checked the PCB file and it’s fine.

#6

im using ubuntu 18.04 with apt-get dist-upgrade
install gqrx with “sudo apt-get install gqrx”
after its installed select ETUS in the drop down menu of gqrx.
i believe my gqrx is version 2.9

#7

I have just received my two LimeSDR Mini boards, and to be honest I was worried a little bit when reading about issues which you guys were reporting. But I have tested both units and found that with the recent version of LimeSuite (downloaded today) they actually work fine both in GnuRadio and in custom SoapySDR-based application.

I have noticed only three non-critical problems:

  • during initialization and closing of my SoapySDR-based application I see several messages of that type: [WARNING] popping from TX, samples popped 0/1020
    This actually started happening for “big” LimeSDR-USB too, when I have updated LimeSuite several months ago, but it does not seem to be causing serious problems,
  • My application is supposed to transmit and receive RF bursts in a loop. At the beginning, there is a series of late packet indications, but after that everything works correctly. Once again, this started to happening with some LimeSuite update for “big” LimeSDR as well,
  • During device setup, both in GNU Radio and my custom app, I am seeing following error: [ERROR] Tx Calibration: MCU error 5 (Loopback signal weak: not connected/insufficient gain?)
    This happens only for LimeSDR Mini, but then it starts streaming and to be honest I am not able to tell what kind of bad things may come from this.

Also, I am quite sure I see some difference in RF loopback (RF TX->RF RX) signal level for both of my Mini boards, but hey, as the USRPs, I am aware that this is not perfectly calibrated laboratory equipment and some differences between performance of particular boards may be expected.

After replacing two “big” LimeSDRs with hardware issues, for now it actually looks like both of my Mini boards work just fine :slight_smile: Make sure you’ll test yours with most recent LimeSuite too!

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