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
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