Receiver gain setting of XCVR2450 in UHD code

[Per_Z]

Hi Josh and List,

In the data-sheet of the MAX2829 circuit two receiver gains are
specified “Receiver Front-End Gain-Control Settings” and “Receiver
Baseband VGA Gain Settings”. From the UHD API we only have one gain
parameter. I have been searching in the UHD code to find where (and how)
the split is done, but I can’t find it…

BR/
Per

[Per_Z]

Am 20.08.2010 08:45, schrieb Per Z.:

[email protected]
Discuss-gnuradio Info Page

–
Hi,

in the old version the gain splitting was done in the firmware @
db_xcvr2450.c .

I don’t have a UHD version available right now to check if this is the
case, too. But it might give you a point where to start.

BR Christoph

[Per_Z]

Controlling gains individually from the api is on my TODO list.
Internally, they are all separated, but the set_xx_gain(…) calls into
this gain_group object that sets the codec + dboard gains as a whole.
See lib/utils/gain_group.cpp

Also give uhd_usrp_probe a run to see the various controllable gain
elements.

-Josh