Suddenly, LimeSDR Mini RF Loopback Test failing?

Hi everyone. I received my Mini board two weeks ago, and I might have fiddled with LimeSuiteGUI for Windows before realizing there was a QuickTest designed for the Mini.

Anyways, I clearly recall the test passing all the four steps (I used the windows version), and then I moved to Linux to install all the related software and try other resources available there.

So far I’ve successfully tested RX of Iridium packets gr-iridium, digital tv with gr-isdbt and local GSM networks with gr-gsm. I even had success transmitting with SDRAngel in the amateur 1.25 meter band, both a local .wav file and the input from the mic, so I was quite happy with the results of the board.

Then, without any reason, I tried the QuickTest (LimeSDR-Mini_QuickTest_1v1) again under Windows 10 and I got the following:

The total output of the test is as follows:

[ TEST STARTED ]
->Start time: Tue Jun 12 13:14:15 2018

->Device: LimeSDR Mini, media=USB 3, module=FT601, serial=1D3AD46807CB9D, index=0
Serial Number: 1D3AD46807CB9D

[ Clock Network Test ]
->REF clock test
Test results: 5165; 18362; 31559 - PASSED
->VCTCXO test
Results : 6711001 (min); 6711163 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
data: 18 02 24 18 02 24 2
->FPGA EEPROM Test PASSED

[ LMS7002M Test ]
->Perform Registers Test
->External Reset line test
Reg 0x20: Write value 0xFFFD, Read value 0xFFFD
Reg 0x20: value after reset 0x0FFFF
->LMS7002M Test PASSED

[ RF Loopback Test ]
->Configure LMS
->Run Tests (TX_2 -> LNA_W):
->On board loopback test:
Test 1:(SXR=1000.0MHz, SXT=1005.0MHz, TXPAD=8): Result:(-31.1 dBFS, 5.00 MHz) - FAILED
->Configure LMS
->Run Tests (TX_1 -> LNA_H):
->On board loopback test:
Test 1:(SXR=2100.0MHz, SXT=2105.0MHz, TXPAD=8): Result:(-12.9 dBFS, 5.00 MHz) - PASSED
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 5.98 seconds

I’m pretty sure I have the latest version of the programs loaded, when I connect the board to LimeSuite I get

INFO: Connected Control port: LimeSDR-Mini FW:5 HW:0 Protocol:1 GW:1.24 Ref Clk: 40.00 MHz

So my questions are:

  1. What does a RF loopback test fail mean? Should I be getting a degraded RX or TX performance because of this?
  2. Did I mess the settings within LimeSuite? (maybe I uploaded a wrong setting to the board?)
  3. What other tests should I run to pinpoint and correct the problem?

Thanks all in advance for any help and thoughts on this

[UPDATE: I just realized that running the “Start Test” again and again gives different output combinations of FAILED/FAILED FAILED/PASSED and even PASSED/PASSED for the two loopback tests…so maybe it’s a initialization issue with the test or board?]

I’ve seen that too.

Sometimes I have to unplug the 'Mini and plug it back in, then run the test again. Once it gets in this state, it doesn’t seem to recover without powering it down.

It could be an initialization problem, but in my case, it seemed to be due to a stream not shutting down properly. Once a stream failed, nothing revived it until the device was unplugged.

I’m seeing a similar issue:

LimeQuickTest --gui
[ TESTING STARTED ]
->Start time: Tue Aug 7 13:27:21 2018

->Device: LimeSDR-USB, media=USB 3.0, module=FX3, addr=1d50:6108, serial=0009070105C6102B
Serial Number: 0009070105C6102B

[ Clock Network Test ]
->FX3 GPIF clock test
Test results: 25334; 29090; 32846 - PASSED
->Si5351C test
CLK0: 17554 / 17554 - PASSED
CLK1: 17554 / 17554 - PASSED
CLK2: 17554 / 17554 - PASSED
CLK3: 17554 / 17554 - PASSED
CLK4: 17554 / 17554 - PASSED
CLK5: 17554 / 17554 - PASSED
CLK6: 17554 / 17554 - PASSED
->ADF4002 Test
Result: 10 - PASSED
->VCTCXO test
Results : 5112949 (min); 5113083 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
->Read data: 11 09 0E 11 09 0E 02
->FPGA EEPROM Test PASSED

[ LMS7002M Test ]
->Perform Registers Test
->External Reset line test
Reg 0x20: Write value 0xFFFD, Read value 0xFFFD
Reg 0x20: value after reset 0x0FFFF
->LMS7002M Test PASSED

[ RF Loopback Test ]
->Configure LMS
->Run Tests (TX_2-> LNA_L):
CH0 (SXR=800.0MHz, SXT=805.0MHz): Result:(-15.2 dBFS, 5.00 MHz) - PASSED
CH1 (SXR=800.0MHz, SXT=805.0MHz): Result:(-17.2 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_1 -> LNA_W):
CH0 (SXR=1800.0MHz, SXT=1805.0MHz): Result:(-15.5 dBFS, 5.00 MHz) - PASSED
CH1 (SXR=1800.0MHz, SXT=1805.0MHz): Result:(-20.3 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_2-> LNA_H):
CH0 (SXR=2500.0MHz, SXT=2505.0MHz): Result:(-19.1 dBFS, 5.00 MHz) - PASSED
CH1 (SXR=2500.0MHz, SXT=2505.0MHz): Result:(-34.6 dBFS, 5.00 MHz) - FAILED
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 1.58 seconds

Not sure what to make of it???

Yeah, I’m not sure what this means…should I expect problems during RX or TX? They seem to be working fine so far (at least in the projects I’m currently interested in…)

I’m having kind of the same issue with a newly reveiced Mini. Tried some local FM stations, but I can only hear some of them. Seems I can only receive stations under 100MHz. I hope it is just a software issue, as shipping took one month :(.

[ TESTING STARTED ]
->Start time: Sun Aug 19 18:25:51 2018

->Device: LimeSDR Mini, media=USB 2.0, module=FT601, addr=24607:1027, serial=1D40F8773AE7A7
Warning: USB3 not available
Serial Number: 1D40F8773AE7A7

[ Clock Network Test ]
->REF clock test
Test results: 20818; 34015; 47212 - PASSED
->VCTCXO test
Results : 6711056 (min); 6711216 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
->Read data: 12 06 1D 12 06 1D 02
->FPGA EEPROM Test PASSED

[ LMS7002M Test ]
->Perform Registers Test
->External Reset line test
Reg 0x20: Write value 0xFFFD, Read value 0xFFFD
Reg 0x20: value after reset 0x0FFFF
->LMS7002M Test PASSED

[ RF Loopback Test ]
->Configure LMS
->Run Tests (TX_2 -> LNA_W):
CH0 (SXR=1000.0MHz, SXT=1005.0MHz): Result:(-44.8 dBFS, 5.00 MHz) - FAILED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-32.1 dBFS, 5.00 MHz) - FAILED
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 3.08 seconds

Update 1: Rerunning the test or replugging the Mini do not change the result, Is my Mini broken?
Update 2: Added a screenshot showing FM stations. Note the noise pattern above 100MHz.

Hi @sven,

Could you please try it with USB3.

Hi @Zack

Also no success.

[ TESTING STARTED ]
->Start time: Tue Aug 28 09:30:43 2018

->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1D40F8773AE7A7
Serial Number: 1D40F8773AE7A7

[ Clock Network Test ]
->REF clock test
Test results: 53526; 1187; 14384 - PASSED
->VCTCXO test
Results : 6711024 (min); 6711185 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
->Read data: 12 06 1D 12 06 1D 02
->FPGA EEPROM Test PASSED

[ LMS7002M Test ]
->Perform Registers Test
->External Reset line test
Reg 0x20: Write value 0xFFFD, Read value 0xFFFD
Reg 0x20: value after reset 0x0FFFF
->LMS7002M Test PASSED

[ RF Loopback Test ]
->Configure LMS
->Run Tests (TX_2 -> LNA_W):
CH0 (SXR=1000.0MHz, SXT=1005.0MHz): Result:(-43.1 dBFS, 5.00 MHz) - FAILED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-30.8 dBFS, 5.00 MHz) - FAILED
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 2.31 seconds

@Zack @IgnasJ Is there something else I can test? Can it be a shielding problem with the aluminium case? Is the board defect?

Hi @sven,

Contact Crowd Supply for replacement, please.

My previous test was done on a MacBook. When I run it on a fresh install on Ubuntu 18.04 I get a

Error: only LimeSDR-Mini is supported
Failed to connect

I am able to connect using the LimeSuiteGUI to the board and read the temp successfully.

Has LimeQuickTest changed or is it different on Linux vs Mac?