Stop_rx_streaming failing (USRP2)

GNU Radio
1

I am directly using libusrp2 in a program, which runs fine the first
time it is executed. At the end of my program I run
stop_rx_streaming, which fails, preventing the program from working
the second time it is run. Why could this command fail? Does the
USRP2 have to be in a certain state before it can be run? Do I have
to do something with the signal handler? Do I have to make sure the
buffer on the USRP2 is empty? Thanks for the help.

  • Michael Leferman
2

On Fri, Aug 21, 2009 at 12:56:13PM -0400, Michael Leferman wrote:

I am directly using libusrp2 in a program, which runs fine the first
time it is executed. At the end of my program I run stop_rx_streaming,
which fails, preventing the program from working the second time it is
run. Why could this command fail? Does the USRP2 have to be in a
certain state before it can be run? Do I have to do something with the
signal handler? Do I have to make sure the buffer on the USRP2 is empty?
Thanks for the help.

  • Michael Leferman

If you’re ever planning on sending a SIGINT (^C) to the program, then
yes, you will need to properly handle the signal. See
usrp2/host/apps/rx_steaming_samples.cc for an example.

Do you have the usrp2 serial console hooked up?
Is it reporting anything? It’s possible that it’s getting wedged
somehow. (If so, the console is ususally streaming a bunch of
"EEEEEE…"s)

Eric

3

On Fri, Aug 21, 2009 at 01:53:25PM -0400, Michael Leferman wrote:

I’m not familiar with the serial console at all, so no, one is not
connected. Can you point me to some documentation on it?

Open the USRP2 up and look at the back edge of the board. There is a
4-pin connector in the back labeled UART. The individual pins are
labeled too. We typically use a CMOS serial to USB adapter, such as
http://www.sparkfun.com/commerce/product_info.php?products_id=199

Talk to it with 230400 8N1

I can hook it up and take a look. Could this be related to ticket 388?
http://gnuradio.org/trac/ticket/388 Thank you for your help.

Could be. Does rx_streaming_samples work for you? or do you see the
same problem. (I know it shouldn’t ever wedge, but I’m wondering
about a work-around.)

Eric

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4

On Aug 21, 2009, at 3:58 PM, Eric B. wrote:

On Fri, Aug 21, 2009 at 01:53:25PM -0400, Michael Leferman wrote:

I’m not familiar with the serial console at all, so no, one is not
connected. Can you point me to some documentation on it?

Open the USRP2 up and look at the back edge of the board. There is a
4-pin connector in the back labeled UART. The individual pins are
labeled too. We typically use a CMOS serial to USB adapter, such as
http://www.sparkfun.com/commerce/product_info.php?products_id=199

Talk to it with 230400 8N1

I didn’t realize I was going to need more hardware for this. This may
take a little bit to get.

I can hook it up and take a look. Could this be related to ticket
388?
http://gnuradio.org/trac/ticket/388 Thank you for your help.

Could be. Does rx_streaming_samples work for you? or do you see the
same problem. (I know it shouldn’t ever wedge, but I’m wondering
about a work-around.)

Yes, rx_streaming_samples does work and so does running usrp2_fft.py
multiple times.