[Discuss-gnuradio] xcvr2450 problems

[Xiaolong Li]

Hi all,

I tried to run tunnel.py with usrp+xcvr2450. However, there were problems 
with the mode switching between tx and rx. The gnuradio trunk version is 
Rev. 10798. Specifically, I have two usrps and some xcvr2450 and 2400 
daughter boards.

First, I ran tunnel.py with two 2400 dbs, everything was fine.

Then I tried with two xcvr2450 dbs. While the tx was fine, the rx failed 
(Packets received were corrupted). More specifically, one usrp sent packets 
of 42 bytes, on receiving side, it showed "Rx: ok = False len(payload) = 
26".

Then I tried benchmark_tx.py and benchmark_rx.py with two 2450 dbs, both tx 
and rx were fine.
I also tried using one 2450 and one 2400, 2400 side can receive packets from 
2450 correctly, 2450 failed receiving again.

So I guess there are something wrong with the mode switch between tx and rx 
with 2450. I looked into the 2450 driver that says "The board operates in 
ATR mode, always.  Thus, when the board is first  initialized, it is in 
receive mode, until bits show up in the TX FIFO." I am wondering if this is 
matter and when the mode switchs back from tx to rx.

BTW, I also tried to switch the order of building txpath and rxpath in 
tunnel.py. While in the case of using 2400, such a switch did not make any 
difference, in the case of 2450, it complained that "failed to set Tx 
frequency to 2.48G".

Any ideas? Thanks a lot.

Best regards,
Xiaolong