Re: [Discuss-gnuradio] inband timestamp issues
Eric Blossom wrote: On Tue, Jul 22, 2008 at 05:59:17PM -0500, Ketan Mandke wrote: My colleague Steve and I have been working with the inband receive code in an effort to understand how the timestamps work. Specifically, we have been printing the timestamps from the usrp_rx block while running test_usrp_inband_2rx.cc in usrp/host/apps-inband. There is some puzzling behavior that we have observed and unable to explain. We are operating with a decimation rate of 64 (i.e. a 1 MHz sample rate). Note, this is using the gnuradio trunk rev 8586, with the gnuradio/trunk/usrp/ code unchanged except to print timestamp data in usrp_rx.cc. There don't seem to be any major changes since this revision. Paging George Nychis,... Paging George Nychis... Please come to the white courtesy telephone... I've known about a inband timestamp issue. but I'm not sure its the same. I've fixed this in the code a while ago, but never committed new RBFs from being busy to build them. Here is the fix I made on 05/15/08: http://gnuradio.org/trac/changeset/8430 I didn't actually get to build the new RBFs until earlier this week: http://gnuradio.org/trac/changeset/8924 http://gnuradio.org/trac/changeset/8935 I'm not sure this fix explains the jumps in timestamps you're seeing, as it was mainly a reset issue causing the TX and RX timestamps to be on different clocks. But, I'd like you to try it out with the new RBFs so we are at least on the same page and I know you're working with the newest and greatest RBFs. Then if the issue still occurs, I can poke before I merge to trunk. If you want my opinion though, I don't think its an FPGA issue, I think that its an underrun issue. Can you try checking if the underrun flag is set on any of the packets around your sudden jumps? You can use the read_packets application in usrp/host/apps-inband to read a packet dump. You can enable the packet dump by editing usrp/host/lib/inband/usrp_rx.cc and setting d_disk_write(true) and d_write_pkt(true): http://gnuradio.org/trac/browser/gnuradio/branches/developers/gnychis/inband/usrp/host/lib/inband/usrp_rx.cc#L47 Just use read_packets on your dump, which should be something like rx_data_chan0.dat and rx_data_chan1.dat ... it should print underrun on the packet if it was set. The 2TX/RX stuff in the inband code is very iffy in my opinion. All of the message passing going on and the context switching between the m-blocks means that the lowest level usrp_rx block might be waiting a while before it gets time on the CPU again ... leaving the FPGA to drop USB blocks in the mean time. But, the underrun flag should tell you this. - George ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] VM Make Check problem : createfilemapping is not available
On Wed, Jul 23, 2008 at 01:39:56PM +1200, Richard Clarke wrote: > Bumped > > Hi All, > > I have been attempting to use a GNU Radio 3.1.2 Virtual Machine (guest OS > is Open Suse 10.2) kindly provided by Chiara De Dominicis, with the USRP. > Initial communications with the USRP were established, enough for firmware > download to the USRP. However when attempting to run any script that makes > use of the USRP the following error is thrown up after a few seconds before > the whole VM crashes into oblivion. > > Terminal message output: gr_check_counting: enter_SEARCHING at offset0 > (0x) > gr_vmcircbuf_createfilemapping: > createfilemapping is not available "createfilemapping is not available" is a normal message. That particular interface is only available when GR is running on win32. For the record, VM's are a completely unsupported configuration. If a particular flavor of VM/host/guest works for you, great. If not, best of luck :-) The USRP attempts to drive the USB as fast as possible... Eric ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] VM Make Check problem : createfilemapping is not available
Bumped Hi All, I have been attempting to use a GNU Radio 3.1.2 Virtual Machine (guest OS is Open Suse 10.2) kindly provided by Chiara De Dominicis, with the USRP. Initial communications with the USRP were established, enough for firmware download to the USRP. However when attempting to run any script that makes use of the USRP the following error is thrown up after a few seconds before the whole VM crashes into oblivion. Terminal message output: gr_check_counting: enter_SEARCHING at offset 0 (0x) gr_vmcircbuf_createfilemapping: createfilemapping is not available Now, I've also created my own Ubuntu 8.04 VM with GNURadio 3.1.2 built from source (svn trunk) and installed. I got as far as the 'make check'. All tests passed EXCEPT one relating to gr_vmcircbuf_createfilemapping: The specific messages are: Testing gr_vmcircbuf_createfilemapping_factory... gr_vmcircbuf_createfilemapping: createfilemapping is not available .gr_vmcircbuf_createfilemapping: createfilemapping: Doesn't work from here on all other tests pass OK. The same kind of error occurs when just trying to run the dial_tone.py example script. So, there is a point of common failure between the 2 VM's. Does anyone have a clue as to what might be the cause for this failure and what if anything can be done to rectify it? If there is any more info I can provide that may help with a diagnosis then please let m know and I'll do my best to obtain it. Thanks for any assistance. Cheers Richard === This email, including any attachments, is only for the intended addressee. It is subject to copyright, is confidential and may be the subject of legal or other privilege, none of which is waived or lost by reason of this transmission. If the receiver is not the intended addressee, please accept our apologies, notify us by return, delete all copies and perform no other act on the email. Unfortunately, we cannot warrant that the email has not been altered or corrupted during transmission. === ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] inband timestamp issues
On Tue, Jul 22, 2008 at 05:59:17PM -0500, Ketan Mandke wrote: > My colleague Steve and I have been working with the inband receive > code in an effort to understand how the timestamps work. Specifically, > we have been printing the timestamps from the usrp_rx block while > running test_usrp_inband_2rx.cc in usrp/host/apps-inband. There is > some puzzling behavior that we have observed and unable to explain. We > are operating with a decimation rate of 64 (i.e. a 1 MHz sample rate). > > Note, this is using the gnuradio trunk rev 8586, with the > gnuradio/trunk/usrp/ code unchanged except to print timestamp data in > usrp_rx.cc. There don't seem to be any major changes since this revision. Paging George Nychis,... Paging George Nychis... Please come to the white courtesy telephone... Eric ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] inband timestamp issues
My colleague Steve and I have been working with the inband receive code in an effort to understand how the timestamps work. Specifically, we have been printing the timestamps from the usrp_rx block while running test_usrp_inband_2rx.cc in usrp/host/apps-inband. There is some puzzling behavior that we have observed and unable to explain. We are operating with a decimation rate of 64 (i.e. a 1 MHz sample rate). Note, this is using the gnuradio trunk rev 8586, with the gnuradio/trunk/usrp/ code unchanged except to print timestamp data in usrp_rx.cc. There don't seem to be any major changes since this revision. 1) Every so often we notice that the timestamp difference between packets from channel 0 and channel 1 sometimes changes. This change in timestamp difference is also accompanied by a sudden spike in the timestamp value followed by about 7 usb_packets with very similar timestamps. For example, the trace might look like this for a while: [usrp_rx]: chan 0 received packet len = 504 bytes, ts = 10, diff = 7802 [usrp_rx]: chan 1 received packet len = 504 bytes, ts = 100262, diff = 262 [usrp_rx]: chan 0 received packet len = 504 bytes, ts = 108064, diff = 7802 [usrp_rx]: chan 1 received packet len = 504 bytes, ts = 108326, diff = 262 , where diff = the difference between the current and previous timestamp; and then we get a sudden jump in the timestamp value: [usrp_rx]: chan 0 received packet len = 504 bytes, ts = 180640, diff = 7802 [usrp_rx]: chan 1 received packet len = 504 bytes, ts = 511000, diff = 330360 [usrp_rx]: chan 0 received packet len = 504 bytes, ts = 511990, diff = 990 [usrp_rx]: chan 1 received packet len = 504 bytes, ts = 512988, diff = 998 [usrp_rx]: chan 0 received packet len = 504 bytes, ts = 513982, diff = 994 [usrp_rx]: chan 1 received packet len = 504 bytes, ts = 514972, diff = 990 [usrp_rx]: chan 0 received packet len = 504 bytes, ts = 517138, diff = 2166 [usrp_rx]: chan 1 received packet len = 504 bytes, ts = 518128, diff = 990 and then normal operation will resume, but with a new delay between the two channels: [usrp_rx]: chan 0 received packet len = 504 bytes, ts = 525170, diff = 7042 [usrp_rx]: chan 1 received packet len = 504 bytes, ts = 526194, diff = 1024 [usrp_rx]: chan 0 received packet len = 504 bytes, ts = 533235, diff = 7041 [usrp_rx]: chan 1 received packet len = 504 bytes, ts = 534258, diff = 1023 This behavior can occur multiple times during the operation of test_usrp_inband_2rx.cc and results in a new delay offset between the channels. We noticed that the number of transcient timestamps is approximately equal to the number of usb_packets that would occupy the size of the fifo buffers (16Kbits) that feed rx_buffer_inband in the FPGA code. We think that somehow, the operation of rx_buffer_inband is stalling which would cause these buffers to fill up and then get dumped out at once (which might explain the transient behavior above). Any ideas what might be causing these random jumps in the timestamp? Although this is a made up trace, it is indicative of the behavior we have observed. I can send a real trace if anyone feels it is necessary. 2) Occasionally we see an out of order packet arrive at usrp_rx in the inband code. This timestamp is usually for a packet that should arrive sometime in the future. We are clueless as to why this might be happening. This seems to happen 1 in every 5k-10k usb_packets. -- Ketan Mandke ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] FSK with RFX2400
Jonathan Friedman wrote: Secondally how can I remove the ISM bandpass filter which is by default there with RFX2400. You have to de-solder it. Optionally (in case you don't want to remove the part, since it will be difficult to reinstall it), you could install a jumper (zero-ohm resistor) or (better) a small 10pF capacitor in parallel (there is a pad), but this may cause some weird side-effects if you use the USRP in the ISM band after installation. You need to put a cap of between 25 and 500 pF in that location, AND you need to cut the traces which go to the filter. If you don't you will get weird resonances. Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Multiple USRP's debugging
On Mon, Jul 21, 2008 at 9:46 AM, Douglas Geiger < [EMAIL PROTECTED]> wrote: > I am having trouble getting two USRP's synchronized using the multiple USRP > setup described at http://www.gnuradio.org/trac/wiki/MultiUsrp and > http://www.gnuradio.org/trac/wiki/USRPClockingNotes. I am able to open/get > data from both USRP's independently, and have even crafted a program to > setup simultaneous flowgraphs collecting data from both and feeding them > into BBN's 80211b demodulator. However, I would like to be able to > synchronize the clock on both USRP's (I'm interested in looking at TDOA > between packets). I have not had any luck getting the multi_usrp_oscope.py > program displaying any data - and my attempts at using > usrp_multi.multi_source_align as a source in e.g. the usrp_fft program have > not been successful. Are there any suggestions on where I should be looking > to debug this? I am using the multi_2rxhb_2tx.rbf fpga code, and using > gnuradio-3.1.2 on a laptop running ubuntu hardy heron. > > <[EMAIL PROTECTED]> > I found my problem - I was not properly connecting the j24 jumper (io15,gnd) between the master and slave, so the sync signal was not getting received properly. I still get errors occasionally: Error: counter not continuous. ucounter_begin[1]=200768 +1 != ucounter_begin[2]200828 I assume this is because the master and slave have falling out of sync? Are there any recommendations on how often the master/slave sync should get sent? Also - if I were to add a third USRP, I assume I'd just have to chain the j24 jumper from either the master or slave - and change the enable_master_and_slave() function in usrp_multi.py to enable both slaves? My next goal is to forward-port the multi_usrp code to the development trunk (e.g. using hier_block2, etc.), as my eventual goal is to include the in-band signaling code to get accurate time-stamps from the RF front-end. I assume the current in-band .rbf files are not being built to support the multi-usrp code, correct? I am starting to familiarize myself with the Quartus software and the organization of the usrp verilog code. Doug -- Doug Geiger [EMAIL PROTECTED] ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] usrp_rx_cfile.py
Hi No need to reply to my previous post. I found that usrp_rx_cfile.py is in the utils directory and that it just uses the normal gnuradio file sink, so I'll use that to write to a fifo. Thank you Sebastiaan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] FSK with RFX2400
> Secondally how can I remove the ISM bandpass filter which is by default > there with RFX2400. You have to de-solder it. Optionally (in case you don't want to remove the part, since it will be difficult to reinstall it), you could install a jumper (zero-ohm resistor) or (better) a small 10pF capacitor in parallel (there is a pad), but this may cause some weird side-effects if you use the USRP in the ISM band after installation. Cheers, -Jonathan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] MP scheduler performance scaling
On Sat, Jul 19, 2008 at 09:08:39PM -0700, Eric Blossom wrote: > > See http://gnuradio.org/trac/wiki/MPSchedulerPerformance for pretty > pictures and links to the code and raw data. > I've added graphs showing Altivec performance. The MP scaling on the PS3 is _much_ better with Altivec than without it. I suspect it has something to with the interaction between the dual-thread dispatch and the VSU pipeline. (I'd always thought that SMT / hyper-threading was a crock, but at least in this one case it pays off). Eric ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Altivec
I've added the framework for Altivec, and implemented gr_fir_fff_altivec using it. This gives a speedup of between 1.8 and 3.0 depending on the type of machine it's running on. There's probably another factor of 1.25 - 1.50 that can be obtained by recoding dotprod_fff_altivec.c directly in assembler (I coded it using C intrinsics). The compiler is generating about 20% more instructions in the inner loop than is necessary. Also, it may be possible to improve dispatch by hand-scheduling the assembly. This code lives in the features/mp-sched branch. I'm not planning on doing anything more on Altivec at this time. If you're interested in adding the rest of the support, the framework is complete. Take a look in filter/*-powerpc* and filter/*altivec* Eric ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] How to see what kind of mac/phy schemes?
Thanks Jason. I'm reading some example scripts in the gnuradio-examples folder, and I particularly interested in the /gnuradio-examples/python/digital/tunnel.py. What we are interested in is particularly in the MAC/PHY blocks. Do you know in which directory under gnuradio-core we can find it? Thanks for help. Best, Y Jason Uher wrote: > > Y, > > Have you looked through the code available in in the > gnuradio-examples folder? I t covers the basic of getting started > with the available blocks. > > Also you might want to have a look at the simple gnuradio manual > which covers all of the available functions: > www.ece.jhu.edu/~cooper/SWRadio/Simple-Gnuradio-User-Manual-v1.0.pdf > > If you downloaded (or checked out) the source, most of the code you > will want to look at is in the gnuradio-core folder. Both the python > and C code is there so you can see how to instantiate things and how > to create blocks. A good place to start would be the converter blocks > (ie, float_to_char), they are nice and simple. > > Finally, if you want to write a MAC/PHY block for use with gnuradio > a good place to start would be be here (probably before you dive into > the code): > http://www.gnu.org/software/gnuradio/doc/howto-write-a-block.html > > Jason > > On Tue, Jul 22, 2008 at 12:07 AM, yyzhuang <[EMAIL PROTECTED]> wrote: >> >> Please, I want to know about some details of blocks at >> MAC and PHY layer. E.g., what kind of MAC modules or blocks that gnu >> radio can provide us? I've read the tutorial here >> http://www.nd.edu/~jnl/sdr/docs/tutorials/9.html#tthFtNtAAB but I can >> not find what I want. >> >> Do you guys know whether there is any documentation about those blocks? >> Or >> would you kindly tell me where I can find them in the source code >> directory? Since I'm the only one in our group who is exploring gnu >> radio, it's difficult to read or search without help of others. Thanks >> for help. >> >> >> >> yyzhuang wrote: >>> >>> Hi, >>> >>> I'm a gnu radio newbie. Can anyone tell me how to see what kind of >>> mac/phy >>> schemes gnu radio comes with, and what is the capacity of gnu radio? Is >>> there any documentation about this? >>> >>> Thanks. >>> Y >>> >> >> -- >> View this message in context: >> http://www.nabble.com/How-to-see-what-kind-of-mac-phy-schemes--tp18580307p18582473.html >> Sent from the GnuRadio mailing list archive at Nabble.com. >> >> >> >> ___ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > -- View this message in context: http://www.nabble.com/How-to-see-what-kind-of-mac-phy-schemes--tp18580307p18593914.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] How to see what kind of mac/phy schemes?
Y, Have you looked through the code available in in the gnuradio-examples folder? I t covers the basic of getting started with the available blocks. Also you might want to have a look at the simple gnuradio manual which covers all of the available functions: www.ece.jhu.edu/~cooper/SWRadio/Simple-Gnuradio-User-Manual-v1.0.pdf If you downloaded (or checked out) the source, most of the code you will want to look at is in the gnuradio-core folder. Both the python and C code is there so you can see how to instantiate things and how to create blocks. A good place to start would be the converter blocks (ie, float_to_char), they are nice and simple. Finally, if you want to write a MAC/PHY block for use with gnuradio a good place to start would be be here (probably before you dive into the code): http://www.gnu.org/software/gnuradio/doc/howto-write-a-block.html Jason On Tue, Jul 22, 2008 at 12:07 AM, yyzhuang <[EMAIL PROTECTED]> wrote: > > Please, I want to know about some details of blocks at > MAC and PHY layer. E.g., what kind of MAC modules or blocks that gnu > radio can provide us? I've read the tutorial here > http://www.nd.edu/~jnl/sdr/docs/tutorials/9.html#tthFtNtAAB but I can > not find what I want. > > Do you guys know whether there is any documentation about those blocks? Or > would you kindly tell me where I can find them in the source code > directory? Since I'm the only one in our group who is exploring gnu > radio, it's difficult to read or search without help of others. Thanks > for help. > > > > yyzhuang wrote: >> >> Hi, >> >> I'm a gnu radio newbie. Can anyone tell me how to see what kind of mac/phy >> schemes gnu radio comes with, and what is the capacity of gnu radio? Is >> there any documentation about this? >> >> Thanks. >> Y >> > > -- > View this message in context: > http://www.nabble.com/How-to-see-what-kind-of-mac-phy-schemes--tp18580307p18582473.html > Sent from the GnuRadio mailing list archive at Nabble.com. > > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] USRP source gain problems?
> It could be that we're not returning that value correctly. > There's an open ticket on that one. Actually, yes. I noticed that it returns None in all of the other working examples as well so I just assumed it wasn't the problem and went back to work. Oddly enough I was able to solve the problem by making my initialization code an inherited class from top_block (as is done in some of the examples) rather than a function that returns a created top_block (which always worked before). Thanks again, Jason ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] 2x2 mimo
Hi I am new gnuradio and usrp. I installed and tested gnuradio and usrp. Usrp is running correctly. I have 4x4 USRP. First of all, I want to perform 2x2 mimo alamouti coding. Everybody may send any information about this? Halil ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] usrp_rx_cfile
Hi I need to get USRP samples from Gnuradio to C++. Eric mentioned that a fifo with usrp_rx_cfile is the best approach to do this. All the examples that I see use file_sink. How should I use usrp_rx_cfile? Is it just like usrp_rx_cfile(gr.sizeof_gr_comples,filename)? Then just one more question. If I am sampling at 500kHz (d=128), I will get 1million samples per second when I read this in C++, real first, then complex, and so on, right? Thank you very much. Sebastiaan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] FSK with RFX2400
Hi everyone, I am trying to implement simple FSK system with USRP and I am using two USRP's each with one RFX2400 daughter card. I have tried fsx_tx.py and fsk_rx.py which are available in gnuradio_examples folder. after using tune to set the proper ferquency I was able to run transmitter and receiver sussfully. I didnt change anything else in the example. The problem is data which I receive is too much corrupt (lot of data errors). Can any one suggest what can be the errors or problems and what can I do to get correct data. Secondally how can I remove the ISM bandpass filter which is by default there with RFX2400. I am thankful in advance. Kaleem Ahmad -- View this message in context: http://www.nabble.com/FSK-with-RFX2400-tp18587205p18587205.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
