[Discuss-gnuradio] question of dual transmitter/receiver

[YouheiFujii]

Hi all,

I'd like to ask some questions about dual transmitter/receiver on USRP1.

I want to make dual transmitter/receiver
by remodeling benchmark_tx/rx.py.

In detail,
I want to use two daughterboard (two FLEX400) on one USRP1.
The pair of side-A transmit and receive on 412MHz,
and the pair of side-B transmit and receive on 420MHz.


  USRP1(tx only)        USRP1(rx only)
  +------------+        +------------+
  |            |        |            |
  |db1:        | 420MHz |db1:        |
  | FLEX400(A)------------FLEX400(A) |
  |            |        |            |
  |db2:        |        |db2:        |
  | FLEX400(B)------------FLEX400(B) |
  |            | 412MHz |            |
  +------------+        +------------+


Now I made tx-node's program like attachment file,
and execute this file.
-----
$ sudo python dual_tx.py -f 412M
-----

However, I got the following error.
-----
user:/usr/share/gnuradio/examples/digital$ sudo python dual_tx.py -f 412M
{'verbose': False, 'discontinuous': False, 'samples_per_symbol': 2,
'usrpx': None, 'interp': None, 'fusb_block_size': 0, 'megabytes': 1.0,
'rx_freq': 412000000.0, 'size': 1500, 'show_tx_gain_range': False,
'log': False, 'tx_subdev_spec': (0, 0), 'fusb_nblocks': 0, 'lo_offset':
None, 'tx_gain': None, 'which': 0, 'modulation': 'gmsk', 'excess_bw':
0.34999999999999998, 'bt': 0.34999999999999998, 'interface': 'eth0',
'freq': None, 'bitrate': 100000.0, 'from_file': None, 'tx_freq':
420000000, 'mac_addr': '', 'tx_amplitude': 0.25, 'gray_code': True}
>>> gr_fir_fff: using SSE
Requested TX Bitrate: 100k Actual Bitrate: 125k
@@@@@
{'verbose': False, 'discontinuous': False, 'samples_per_symbol': 2,
'usrpx': None, 'interp': None, 'fusb_block_size': 0, 'megabytes': 1.0,
'rx_freq': 412000000.0, 'size': 1500, 'show_tx_gain_range': False,
'log': False, 'tx_subdev_spec': (1, 0), 'fusb_nblocks': 0, 'lo_offset':
None, 'tx_gain': None, 'which': 0, 'modulation': 'gmsk', 'excess_bw':
0.34999999999999998, 'bt': 0.34999999999999998, 'interface': 'eth0',
'freq': None, 'bitrate': 100000.0, 'from_file': None, 'tx_freq':
412000000, 'mac_addr': '', 'tx_amplitude': 0.25, 'gray_code': True}
usrp_open_interface:usb_claim_interface: failed interface 1
could not claim interface 1: Device or resource busy
usrp_basic_tx: can't open tx interface
Traceback (most recent call last):
  File "dual_tx.py", line 150, in <module>
    main()
  File "dual_tx.py", line 109, in main
    tb = my_top_block(mods[options.modulation], options)
  File "dual_tx.py", line 54, in __init__
    self.txpath_b = usrp_transmit_path.usrp_transmit_path(modulator,
options)
  File "/usr/share/gnuradio/examples/digital/usrp_transmit_path.py",
line 67, in __init__
    self._setup_usrp_sink(options)
  File "/usr/share/gnuradio/examples/digital/usrp_transmit_path.py",
line 76, in _setup_usrp_sink
    self.u = usrp_options.create_usrp_sink(options)
  File "/usr/share/gnuradio/examples/digital/usrp_options.py", line 119,
in create_usrp_sink
    gain=options.tx_gain,
  File "/usr/share/gnuradio/examples/digital/generic_usrp.py", line 199,
in __init__
    _generic_usrp_base.__init__(self, **kwargs)
  File "/usr/share/gnuradio/examples/digital/generic_usrp.py", line 57,
in __init__
    elif usrpx == '1' or self._subdev_spec: self._setup_usrpx(USRP1_TYPE)
  File "/usr/share/gnuradio/examples/digital/generic_usrp.py", line 76,
in _setup_usrpx
    if self._type == USRP1_TYPE: self._setup_usrp1()
  File "/usr/share/gnuradio/examples/digital/generic_usrp.py", line 229,
in _setup_usrp1
    fusb_nblocks=self._fusb_nblocks)
  File "/usr/lib/python2.6/dist-packages/gnuradio/usrp/usrp_swig.py",
line 2412, in sink_c
    return _usrp_swig.sink_c(*args, **kwargs)
RuntimeError: can't open usrp
user:/usr/share/gnuradio/examples/digital$
-----


I think, I couldn't make two txpath.
(I can make "txpath_a", but can't make "txpath_b")
But we can make two path ( txpath and rxpath) in tunnel.py.
Why I can't make two txpath like this way?

I can't  make dual transmit path like this way.

Does anyone has some idea to make ?
If you know, please tell me dual transmit path technique.


Thanks,
youhei

dual_tx.py
Description: Text Data