Trondeau C++ daughterboard code

GNU Radio
1

Dear All,

I am trying to migrate from home-made daughterboard code to the code by
Trondeau. I am using the version 9305. I use db_flexrf_1800_tx_mimo_b.
After changing “d_common->R_DIV(1)” to “d_common->R_DIV(16)” the signal
is
showing up on my spectrum analyzer at the correct frequency. However,
the
amplitude is about 25dB weaker than when using the home-made
daughterboard
code. I am using the daughterboard code as given by the code fragment
below.
Does anyone have an idea what could be wrong ?

BR/
Per

usrp_standard_tx* tx = usrp_standard_tx::make(0,64,2,47768);
std::vector<db_base_sptr> db_rx0,db_rx1,db_tx0,db_tx1;

db_tx0=tx->db(0);
db_tx1=tx->db(1);

db_tx0[0]->set_lo_offset(tx_lo_offset);
tr=db_tx0[0]->tune(0,carrier_frequency);

db_tx0[0]->set_enable(true);
db_tx0[0]->set_gain(db_tx0[0]->gain_max());

2

On Monday 06 October 2008 18:02:29 Per Z. wrote:

Dear All,

I am trying to migrate from home-made daughterboard code to the code by
Trondeau. I am using the version 9305. I use db_flexrf_1800_tx_mimo_b.
After changing “d_common->R_DIV(1)” to “d_common->R_DIV(16)” the signal is
showing up on my spectrum analyzer at the correct frequency. However, the
amplitude is about 25dB weaker than when using the home-made daughterboard
code. I am using the daughterboard code as given by the code fragment
below. Does anyone have an idea what could be wrong ?

The DB code sets the gain in the 9862 to the wrong value (there is
something
wrong with the calculation of the register value from the gain in db) -
this
may be fixed in the cppdb feature branch.

Stefan

–
Stefan Brüns / Bergstraße 21 / 52062 Aachen
mailto:lurch at gmx.li http://www.kawo1.rwth-aachen.de/~lurchi/
phone: +49 241 53809034 mobile: +49 151 50412019

3

On Monday 06 October 2008 19:31:04 Stefan Brüns wrote:

The DB code sets the gain in the 9862 to the wrong value (there is
something wrong with the calculation of the register value from the gain in
db) - this may be fixed in the cppdb feature branch.

Patch attached.

Stefan

4

On Monday 06 October 2008 20:30:36 Stefan Brüns wrote:

On Monday 06 October 2008 19:31:04 Stefan Brüns wrote:

The DB code sets the gain in the 9862 to the wrong value (there is
something wrong with the calculation of the register value from the gain
in db) - this may be fixed in the cppdb feature branch.

Patch attached.

Stefan

Sorry, wrong one, only the last hunk is the correct part.

Attached again.

Stefan