Mini not passing LimeQuickTest


#1

Hello MyriadRF and fellow RF Enthusiasts, I may be in a bit of a pickle here, and need some advice.
I have LimeSDR Mini, used it several times for very basic RF experiments, like tuning FM radio and sweeping
CB bands, but nothing more, basically getting myself familiar with SDR portion of RF trade.
This week I decided to put together dedicated linux machine to experiment with, and followed one of the guides to
properly set things up. Guide recommended running “LimeQuickTest” or “LimeQuickTest --gui” application to test the board, which I did and found out that it does not pass first segment of the test.
Here’s relevant portion of test log:

[ TESTING STARTED ]
->Start time: Fri Feb 1 08:52:02 2019

->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1D424B338C0E6C
Serial Number: 1D424B338C0E6C

[ Clock Network Test ]
->REF clock test
Test results: 62890; 10551; 23748 - PASSED
->VCTCXO test
Results : 6711019 (min); 6711019 (max) - FAILED
FAILED
->Clock Network Test FAILED

To note, couple things, before running this test I ran firmware upgrade, which went without issues and even though board is getting failed test status, it works fine for basic experiments.
I want to understand the severity of my problem, and any possible solution that I can try.
I’ve trie looking around Wiki for VCTCXO calibration procedure, and found many references that it’s possible, but couldn’t find any step by step ones.

Also, looked over at github at detailed instructions, but unfortunately that’s a deep end of things for me and I’m quite lost there.

How screwed am I?
Thank you.


#2

Paging @Zack for comment.


#3

Hi @Malexander88,

It looks like something wrong with VTune voltage coming from DAC to VCTCXO. If you have a multimeter at least, we can start to debug it.


#4

@Zack, I have basic electronics lab, decent multimeter (fluke 87V) ,entry level rigol o-scope and freq-gen, and at work I have access to old uncalibrated HP spectrum analyzer and VNA stack, if needs be. Also I have decent assortment of RF passive components.

Let’s do this!


#5

Hi @Malexander88,

Excellent! :slight_smile:

Could you measure for me 3 voltages as indicated in picture, please. Do 2 measurements:

  1. Connect to the board, go to Modules -> Board controls. Change VCTCXO DAC (runtime value) to 0, push Enter. Measure 3 voltages.
  2. Go to Modules -> Board controls. Change VCTCXO DAC (runtime value) to 65000, push Enter. Measure 3 voltages again.
  3. Let me know these voltages.

#6

Alright @Zack , Measurements done, they are as follows:

Default Value: 180
Meas VDD: 3.307
Meas VOUT: 2.329
Meas TCXO_VC: 0.119

Zero Value: 0
Meas VDD: 3.307
Meas VOUT: 0.018
Meas TCXO_VC: 0.119

Max Value: 65000
Meas VDD: 3.306
Meas VOUT: 3.293
Meas TCXO_VC: 0.119

However, I believe R67 resistor is not on the board. See attached picture.

Thank you.


#7

Wow! That’s the issue. Just checked factory test log, everything is OK. From the picture you can see that resistor was definitely soldered. It was kicked off at some point.
To fix it you should solder 3kOhm resistor there. From your measurements I see that DAC is working hence everything should be OK after you solder the resistor.


#8

Awesome!
I found appropriate resistor (Failed Lenovo Tiny PC motherboard, registered 3K on the dot) and soldered it on the Mini, it now passed the test every time I ran it. Is there any calibrations I need to perform, to adjust for resistor being slightly different? I can attach test log, but I think I’m actually good here.

Thank you @Zack!


#9

Hi, I have a similar problem with my LimeSDR mini not passing the LimeQuickTest.

I have a functioning unit (1) that passes and a failing unit (2).

Logs below.

What should I check for on unit 2 ?

LimeQuickTest

[ TESTING STARTED ]
->Start time: Thu Feb 7 19:38:03 2019

->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1D42336356BE75
Serial Number: 1D42336356BE75

[ Clock Network Test ]
->REF clock test
Test results: 52791; 452; 13649 - PASSED
->VCTCXO test
Results : 6711057 (min); 6711213 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
->Read data: 12 07 18 12 07 18 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:(-13.5 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-13.1 dBFS, 5.00 MHz) - PASSED
->RF Loopback Test PASSED

=> Board tests PASSED <=

Elapsed time: 2.50 seconds

LimeQuickTest

[ TESTING STARTED ]
->Start time: Thu Feb 7 19:39:03 2019

Command not supported
Command not supported
Command not supported
->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1D4233D4AA7352
Serial Number: 1D4233D4AA7352
Command not supported

[ Clock Network Test ]
->REF clock test
Command not supported
Command not supported
->REF clock test FAILED
->VCTCXO test
Command not supported
FAILED
->Clock Network Test FAILED

[ FPGA EEPROM Test ]
->Read EEPROM
Operation failed: error code 2
->FPGA EEPROM Test FAILED

[ LMS7002M Test ]
->Perform Registers Test
Command not supported
SPI_write() failed
Command not supported
SPI_write() failed
Command not supported
SPI_write() failed
Command not supported
Command not supported
Command not supported
Command not supported
Command not supported
->LMS7002M Test FAILED

[ RF Loopback Test ]
->Configure LMS
Command not supported
Command not supported
Command not supported
Command not supported
Command not supported
Command not supported
Failed to set sample rate
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 0.86 seconds


#10

Hi @andy123, your failed test log doesn’t look anything like mine did,
almost like your mini missing some firmware, let’s see what @Zack
can tell you, as far as I know, he’s a wizard.


#11

I can confirm that @Zack is definitely a wizard when it comes to such matters :smiley:


#12

My LimeSDR Mini always fails on the [Rf Loopback Test] on windows 7 and ubuntu 16.04. On Macosx Sierra - it sometimes passes both tests, but mostly fails on the second test. Is there anything to do to fix the problem ?

[dir:~] dir% LimeQuickTest
[ TESTING STARTED ]
->Start time: Fri Feb 8 08:25:01 2019

->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1D40E98019939A
Serial Number: 1D40E98019939A

[ Clock Network Test ]
->REF clock test
Test results: 55977; 3638; 16835 - PASSED
->VCTCXO test
Results : 6710958 (min); 6711117 (max) - PASSED
->Clock Network Test PASSED

[ FPGA EEPROM Test ]
->Read EEPROM
->Read data: 12 06 1C 12 06 1C 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:(-18.8 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-20.4 dBFS, 5.00 MHz) - FAILED
->RF Loopback Test FAILED

=> Board tests FAILED <=

Elapsed time: 2.49 seconds


#13

Also having issues with the Clock Network test failing. I was using srsLTE successfully for a while, and then I began having issues with the network not being seen. Seems I’m missing R67 as well. Time for a Digikey order…

[ TESTING STARTED ]
->Start time: Mon Mar 18 21:50:25 2019

->Device: LimeSDR Mini, media=USB 3.0, module=FT601, addr=24607:1027, serial=1D4C3CE1507EBE
Serial Number: 1D4C3CE1507EBE

[ Clock Network Test ]
->REF clock test
Test results: 40841; 54038; 1700 - PASSED
->VCTCXO test
Results : 6710999 (min); 6710999 (max) - FAILED
FAILED
->Clock Network Test FAILED

[ FPGA EEPROM Test ]
->Read EEPROM
->Read data: 13 02 0D 13 02 0D 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:(-13.1 dBFS, 5.00 MHz) - PASSED
->Run Tests (TX_1 -> LNA_H):
CH0 (SXR=2100.0MHz, SXT=2105.0MHz): Result:(-12.9 dBFS, 5.00 MHz) - PASSED
->RF Loopback Test PASSED

=> Board tests FAILED <=


#14

After adding R67…

[ Clock Network Test ]
->REF clock test
Test results: 51601; 64798; 12459 - PASSED
->VCTCXO test
Results : 6711027 (min); 6711184 (max) - PASSED
->Clock Network Test PASSED