Communication TEST

GNU Radio
1

Hi all

I’ve installed Gnuradio/USRP on the FC5 64 distribution and everything
seems
to work fine. I launch following examples:

./test_usrp_standard_tx and get

tx_underrun
xfered 1.34e+08 bytes in 4.2 seconds. 3.199e+07 bytes/sec. cpu time =
0.028
1 underruns

then

./test_usrp_standard_rx and get

xfered 1.34e+08 bytes in 4.19 seconds. 3.2e+07 bytes/sec. cpu time =
0.032
noverruns = 0

My daugtherboard is a flex2400. To test its goodness I launch:

./benchmark_tx.py -f 2412000000.0 -v and I get

gr_fir_fff: using 3DNow!
bits per symbol = 1
Gaussian filter bt = 0.35
Using TX d’board A: Flex 2400 Tx
Tx amplitude 12000
modulation: gmsk_mod
bitrate: 500kb/s
samples/symbol: 2
interp: 128
Tx Frequency: 2.412G
…

and

./benchmark_rx.py -f 2412000000.0 -v and I get

gr_fir_fff: using 3DNow!
bits per symbol = 1
M&M clock recovery omega = 2.000000
M&M clock recovery gain mu = 0.050000
M&M clock recovery mu = 0.500000
M&M clock recovery omega rel. limit = 0.005000
frequency error = 0.000000
Using RX d’board A: Flex 2400 Rx
Rx gain: 45
modulation: gmsk_demod
bitrate: 500kb/s
samples/symbol: 2
decim: 64
Rx Frequency: 2.412G

Besides, if I launch ./usrp_oscope.py -f 2.4G I get

** (python:4994): WARNING **: IPP request failed with status 1030

** (python:4994): WARNING **: IPP request failed with status 1030
uO

with a windows showing the oscilloscope.

My question is: why if I launch ./benchmark_tx.py -f 2412000000.0 -v on
a tx
machine and /benchmark_rx.py -f 2412000000.0 -v on a rx machine, the rx
one
is not receiving anything? No packets!
And if I launch /usrp_oscope.py -f 2.4G on the rx machine and then I
generate 802.11b traffic at 1 Mbit, why am I not seeing any signal
intensity
variation on the oscilloscope?
In the end, am I needed to pre-install particoular flex2400 firmwares
before
starting examples or those firmwares are directly loaded when I launch
the
examples?
Is it possible to get a clear description (scripts I mean) about
creating
communications between USRPs standing on different machines?

10x a lot

Roberto

2

On Fri, Oct 20, 2006 at 10:55:46AM +0200, Roberto M. wrote:

bitrate: 500kb/s
bits per symbol = 1
decim: 64

communications between USRPs standing on different machines?

10x a lot

Roberto

Have you read the README in gnuradio-examples/python/digital?

Eric

3

Roberto

I’ve installed Gnuradio/USRP on the FC5 64 distribution and everything

gr_fir_fff: using 3DNow!

frequency error = 0.000000
** (python:4994): WARNING **: IPP request failed with status 1030
generate 802.11b traffic at 1 Mbit, why am I not seeing any signal
intensity variation on the oscilloscope?

Have you adjusted the vertical scaling? You’ll also want to make sure
you
set your center frequency on the channel you’re transmitting on (2.412
MHz,
like you were using above).

Do you have a 802.11 access point nearby running on channel 1? It could
be
causing interference to the GNU Radio signal (though I’d expect some
packets
to still get through).

Do you have antennas connected, or are you doing it over cable? If
cable,
are you attenuating it at all?

Do you have a spectrum analyzer of power meter that you can test to make
sure you’re actually transmitting something?

In the end, am I needed to pre-install particoular flex2400 firmwares
before starting examples or those firmwares are directly loaded when I
launch the examples?

No you don’t have to do anything for this.

Is it possible to get a clear description (scripts I mean) about creating
communications between USRPs standing on different machines?

10x a lot

Roberto

Tom