Register Cache


#1

Stupid question, I’ve read through the source. Is the cache saved to file in a Windows environment, if so where?

I’m currently failing to get the TX Calibration values saved, that may be the usual idiot programmer problem though.


#2

If you mean calibration cache, this is no longer used and calibration is instead performed by the MCU on-the-fly.


#3

Andrew,

Thanks - do I have to enable something so that Transmit Calibration is automatically performed? I can confirm that unless I manually run calibration no effective calibration happens.

There’s a big carrier in the centre of the transmission which only goes away after calibrating.

I guess I’m missing an important step.


#4

Certainly the old file based cache that was used back with host-based calibration is deprecated.

As far as I knew calibration is performed automatically by the LMS7002M MCU whenever you (re)tune etc. Though perhaps you do need to manually calibrate sometimes and @IgnasJ could advise.


#5

Looking at the source code, it looks like the calibration has to be initiated manually.


#6

So what’s the calibration that occurs whenever you (re)tune? Is this just receive chain calibration?


#7

Whenever you change Rx/Tx center frequency, only the VCO is being retuned automatically.

As far as DC/IQ calibration is concerned, the calibration expects that the Rx/Tx is in final working configuration, which only the user knows when that state is ready. Otherwise if the calibration would be made to be called automatically, it’s most likely that it would report a bunch of errors (“gain too low, frequency not locked, channel not enabled…”) with most of each parameter change while the user’s initial state is being configured.


#8

Thanks for the clarification. Getting back to @SimonG4ELI’s question, is this calibration cached anywhere? Had thought we’d done away with caching values, e.g. in ~/.limesuite on Linux.


#9

The calibration results are not being cached anymore.


#10

Hi,

Which values should I save / restore for TX Calibration? When a user restarts the software the frequencies and sample rates are usually the same, so it makes sense to restore the previous calibration.


#11

#12

Excellent, thanks.