LimeSDR Mini bringup

Hi
trying to get my LimeSDR to do anything

Right now Ive not had a great OOTB experience.

Notes:

  1. Had to reinstall the USB drivers from FTDI (although no errors shown in Device manager)
  2. LimeUtil --update works
  3. LimeQuickTest.exe gives no results (no feedback to user at all)
  4. The mini gets v hot (estimate bottom of PCB to be about 55C). Is that normal?
  5. often only connects at USB=2 rather than USB=3 (reported by LimeUtil --find)

how to get LimeQuickTest.exe to do anything (even basic user feedback - like device not found)?

To try if it works: LimeSuiteGUI has a spectrum viewer under Modules/FFTviewer. There you could enter the frequency of a local FM radio station and should see something.

Sorry to hear, and welcome to the team. It does not work for a lot of people. A lot. Actually for some people if performs equally whether it is inside the box or connected to your computer. You will notice it works on a limited basis for most people, and apparently it works perfectly for about 2 people on this forum. Regardless, the reason it is not working is your fault. It has been stated here several times, that apparently you have to be either an engineer or a coder to be able to make it work. Either way do not expect any support, no one has gotten any over the last few months. I read the other day on my twitter feed that there were some users grouping for a class action, unsure if that’s any accurate or not.

It does get warm and 55C is fine.

Odd that LimeQuickTest is giving no results. Do you have another computer you could try this on? We have seen issue sometimes with certain USB 3.0 chipsets, where this has been resolved by using another adapter or computer.

More info under Win10
LimeQuickTest included with PothosSDR-2018.07.20-vc14-x64.exe does NOTHING
(actually the Lime*.exe return no information upon failure)
LimeQuickTest_20180702_01e2d00.exe works can someone get Pothos people to include updated file?

Often only get USB2 connection (until re-plugin)
Note I have my own RF lab (with VNAs up to 26GHz, SA, even an old 89410 SA) - so I know my way around equipment, but from a new user POV my experience is not very good - almost nothing works well.
At this stage in the SDR game I was hoping that it would be:

  1. Install exe
  2. Run simple application that shows a spectrum sweep (e.g. of WiFi band - which everyone has access to).

Right now it’s a mishmosh of half-baked SDR apps and LimeSuite FFT viewer “not responding” is basically its default state.

Can someone confirm that
https://wiki.myriadrf.org/Testing_the_LimeSDR
2.4.1 Loading the Test Waveform
Will Not work with the LimeSDR mini?
Is there any easy way to test Tx on the mini (and see an actual output on a spectrum analyzer)? <- note to self, have hacked together some Pothos code to get an output. will post some info later.

The Pothos Windows installer is maintained by @joshblum. Sounds like bundled LimeQuickTest.exe may need updating, Josh?

Correct, it will not, since it does not have the DDR memory required to load the waveform file in to.

@Zack, could you suggest any further simple tests?

THIS ^^^

Well fortunately, I am both. Not that it makes a difference. And although I am not an RF engineer, I had zero issues getting the Ettus N200 up and running. I was hoping the LimeSDR Mini would be a more cost effective similar solution with smaller footprint (and reduced capabilities would be fine with me, we are doing very basic LTE network simulation). But if I have to start reverse engineering this board to the point that I could quit my job and be part of the design team, that’s just ridiculous. If it had been made clear to me this was super experimental hackware, I would have opted for the LimeSDR in lieu of the mini.

Correct, it will not, since it does not have the DDR memory required to load the waveform file in to.

Then please update the SW so that these options are greyed out on unsupported HW - also note this in the Mini bring-up documentation.

I request that some way of loopback (maybe a QPSK signal as this will look nice on I/Q views) is provided within SW that Lime has complete ctrl over (e.g. not relying on other) so that a user can see comms happening in both Tx and Rx mode.

This example should be scaled to allow it to work over a USB 2 link as 50% of the time that is all that I get when I connet the LimeSDR mini.

Right now the default streaming settings in FFTviewer don’t %$#" work for me.

Unforunately FM is pretty much off here in Norway. The Antenna Band and Rx settings and inscrutable in the LimeSuite GUI and relying on 3rd party tools to do a basic check is bad engineering practice IMO as there are too many variables outside of the ctrl of the devs

LimeSDR seems to be linked to Pothos in the sense that that is what we are requested download, but afterwards there is 0 basic information.

I really expected to find a basic Pothos setup for transmitting, say an FM modulated signal + summing in some noise, for example. LimeSDR seem to provide no simple examples that can be downloaded that show a basic setup with some sliders for
Tx Freq
Rate <- does this need to match on all blocks?
Tx Rate <- again - allowed values? this info is still listed as TBC in the project HW page.
Automatic Band selection according to freq. (Band 1 <2GHz, Band 2> 2GHz? - default does nothing?)
Sensible gain settings

With all due respect, trying to learn Pothos which without a couple of LimeSDR Mini specific examples that can be downloaded from the LimeSDR Mini wiki page is very frustrating. And would require about 1 day of work for the dev team as they - then people could play with a “known” good program (and good practices for structure of a Pothos program).

Now, I’m an RF engineer by day, I’ve programmed AD DDSs in the past with microcontrollers, and a couple of PLLs, so I understand the switches, but not the particulars of the Lime chipset - and that should not be necessary. I do some basic Python for instrument control, and I literally design spacecraft payload HW. I personally own a Tektronix RSA306B so I can at least see what my LimeSDR is doing and even then it’s hard to understand how to control the thing. I can accept RTFM, but after a very basic install, the wiki just seems to say: well have fun - download some SDR sw from a bunch of half-baked repositories - 50% only work under windows the other 50% only under Linux.

Issue number 543233: where are the specs for the LimeSDR mini ??
https://wiki.myriadrf.org/LimeSDR-Mini#Features_and_Specifications

Important info in not listed or is TBD

When HW is at the shipping stage, the customer should be able to quickly find out specs for:
Transmit power versus freq. at each (of 2?) bands
Rx sensitivity (noise floor) at each band
Right now I don’t even know what frequencies I should be able to receive (!)

An no, I’m not going to waste my time with the LMS7002 datasheet, the schematics and a simulator plotting theoretical curves - this is basic info that should be clearly measured and listed.
Someone that understands the LimeSDR settings and has a sig gen should be able to plot this in 1-2 days.
As I don’t understand all the settings in LimeSuite, I have no idea when I measure, for example:
Sign gen set to 155.1MHz, -83dBm
FFTviewer: -54dBFS (hamming window)
Is that correct, WTF should I expect???

I hope to help move this LimeSDR Mini forward to something that I can recommend to colleagues.

73 de L

Well the chips themselves are well above 50C as they are uncomfortable to touch. I wouldn’t normally release that without a heatsink - any suggestions for adhesive thermal tape (double sided) and a small heatsink for the main IC + FPGA?

USB3 work about 30% of the time (plug-in/out)

lol. as i just unplugged my lime-mini showing ‘LimeUtil --find’ = usb 2.0
so i take out and plug back in and its usually usb 3.0 then

it dont happen to much only when i first plug mine in.
if it happens later i just pull out real fast then put back in and its usually usb 3.0.
i think what is causing it to show usb 2.0 is how fast and steady you insert it.
after its always plugged in the first time i just pull it out a little bit of the laptop usb port that plug back in.
its always straighter and faster then when i first pick up my lime-mini and first plugged in.