LimeSDR-XTRX PPS does not work

LimeOn · 1 February 2025 14:26

There is PPS U.FL connector on the XTRX board.
Also we have the waitPPS field is the StreamConfig structure of the
Limesuiteng library.

We set the value of waitPPS to “true” and started the Tx stream. LimeSDR-XTRX started the Tx stream regardless of the value of waitPPS.

Does this functionality work?

ricardas · 1 February 2025 23:48

The stream wait for PPS, was initially implemented for a different board.
Currently XTRX gateware does not provide it, as the control bits overlap needs to be resolved. @VytautasB could you verify if such funtionality will be in XTRX gateware?

github.com

myriadrf/LimeSuiteNG/blob/65d5caafa34b20f95ee426f82193d10449c4cab8/src/streaming/TRXLooper.cpp#L160-L162


      
          // XTRX has RF switches control bits where the GPS_PPS control should be.
          bool hasGPSPPS = fpga->ReadRegister(0x0000) != LMS_DEV_LIMESDR_XTRX;
          if (hasGPSPPS)

VytautasB · 3 February 2025 07:42

Hi @LimeOn,

yes, this functionality is not currently implemented on LimeSDR-XTRX board. I am adding it to backlog.