Can't get LimeSDR to work: Tx Calibration: MCU error 5

Projects LimeSDR
1

I’m having a problem with my new LimeSDR boards. I am trying to run the LoRa example from here:
LoRa modem with LimeSDR – MyriadRF

and I get the hollowing output:

[15:34:42.655221] PothosFlow.MainWindow: Welcome to Pothos v0.6.1-PothosSDR-2018.04.26-vc14-x64
[15:34:42.754976] PothosFlow.GraphEditor: Loading C:/Users/ak/Documents/SDR/LoRa-SDR/examples/lora_sdr_relay.pothos
[15:34:43.140839] PothosFlow.MainWindow: Initialization complete
[15:34:44.782000] SoapySDR: Make connection: ‘LimeSDR-USB [USB 3.0] 9070602431B19’
[15:34:44.962000] SoapySDR: Reference clock 30.72 MHz
[15:34:44.963000] SoapySDR: Device name: LimeSDR-USB
[15:34:44.963000] SoapySDR: Reference: 3.072e+07 MHz
[15:34:45.342000] SoapySDR: LMS7002M calibration values caching Disable
[15:34:46.086000] : [INFO] [UHD] Win32; Microsoft Visual C++ version 14.0; Boost_106300; UHD_3.11.0.1-0-ge00f1f37
[15:34:53.743000] SoapySDR: Tx Calibration: MCU error 5 (Loopback signal weak: not connected/insufficient gain?)
[15:34:53.916000] SoapySDR: Rx calibration finished
[15:34:54.629000] SoapySDR: popping from TX, samples popped 0/1020
[15:34:55.509000] SoapySDR: popping from TX, samples popped 0/1020
[15:34:56.520000] SoapySDR: popping from TX, samples popped 0/1020

If I connect the board to LimeSuite and try ‘Calibrate All’ I get the same error:

[12:57:04] INFO: Reference clock 30.72 MHz
[12:57:04] INFO: Connected Control port: LimeSDR-USB FW:4 HW:4 Protocol:1 GW:2.16 Ref Clk: 30.72 MHz
[12:57:08] ERROR: Tx Calibration: MCU error 5 (Loopback signal weak: not connected/insufficient gain?)

If, however I update the firmware from LimeSuite (Modules->Programming), reset the module to ‘Default’ configuration, calibration with LimeSuite is successful, but as soon as I try to run the LoRa example, it fails again with the same error, and LimeSuite cannot calibrate until I reprogram the board.

I’m working on Windows 10, x64 if it matters. I tried this on two boards and the results are identical. Any help would be appreciated.

2

“insufficient gain”, you need to increase transmitter gain.

3

That was it, thank!

4

using good antenna or using power amplifier for the Tx reslove the problem?
How about the Rx,?

5

calibration is done using internal loopback, it does not depend on external elements (antennas, amplifiers…)

6

But you said that i should increase transmitter gain? how to process so if it’s on internal ? That I misunderstand is, where did the loopback obtain the gain.

7

You need to increase Tx/Rx gain by changing the chip configuration settings. I have no idea what software you are using, so I can’t tell you exactly how to do it. LimeSuite API has LMS_SetNormalizedGain or LMS_SetGaindB functions

8

I use limesuite with soapyUHD and it’ appears on it.
– Make connection: ‘LimeSDR Mini [USB 3.0] 1D3AC779327FE0’

– Reference clock 40.00 MHz

– Device name: LimeSDR-Mini

– Reference: 40 MHz

– LMS7002M calibration values caching Disable
UHD Error:

Tx Calibration: MCU error 5 (Loopback signal weak: not connected/insufficient gain?)

– Rx calibration finished
UHD Warning:

popping from TX, samples popped 540/1020

i will send you the version of my limesuite and uhd if you need it and if you have any solution for it?

9

Mine also @ricardas with soapyUHD i have this error : Tx Calibration: MCU error 5 (Loopback signal weak: not connected/insufficient gain? but with limesuite the calibration is fine. i don’t know how to fix it !

10

I solved This Problem Osmocom set up 2.5 5 mhz on their orginal settings osmo-trx İf you write all of information antenna sampling code vs İt will start . But orginal osmo-trx settings you can not change . İt can be 120 Mhz singal transmitting I have performed now . But dont do 900 Mhz . İn my opion you use limesdr module.

11

dont Forget İf you dont put Antenna: BAND1 İt can not send signal