# USRP 1 overflow problem **URL:** \ **Category:** GNU Radio\ **Created:** [November 20, 2014, 11:33am UTC](https://www.ruby-forum.com/t/usrp-1-overflow-problem/233159 "2014-11-20T11:33:57Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [November 20, 2014, 11:33am UTC](https://www.ruby-forum.com/t/usrp-1-overflow-problem/233159/1 "2014-11-20T11:33:57Z")
Hello All, I have just started learning SDR and new to USRP as well for GNU radio. SInce i am just a beginner, so i started with very basic examples benchmark\_tx.py and benchmark\_rx.py on USRP1. I am using daughter board WBX. I am getting an overflow problem both for receiver and uhd\_fft as well. I tried to search on google but there was no clue for USRP1. Please help me out to this very initial example problems. Thank you, in advance. Below is the command i am passing for tx and rx benchmark\_tx.py -a serial=49270a48 -f 2.2G -m gmsk -r 240 --tx-gain=20 –tx-amplitude=0.8 in another terminal for benchmark\_rx i am passing this benchmark\_rx.py -a serial=4d05ac4b -f 2.2G -m gmsk -r 240 --rx-gain=20 forrx and alsofor uhd\_fft it is printing the same oooooooo continues. Thank you. ---
**Author:** ![alok\_ranjan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/94ad74/32.png) [@alok\_ranjan](https://www.ruby-forum.com/u/alok_ranjan)\ **Post date:** [November 20, 2014, 3:34pm UTC](https://www.ruby-forum.com/t/usrp-1-overflow-problem/233159/2 "2014-11-20T15:34:40Z")
On Thu, Nov 20, 2014 at 5:32 AM, alok ranjan [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > _benchmark\_tx.py -a serial=49270a48 -f 2.2G -m gmsk -r 240 --tx-gain=20 > –tx-amplitude=0.8_ > > in another terminal for benchmark\_rx i am passing this > _benchmark\_rx.py -a serial=4d05ac4b -f 2.2G -m gmsk -r 240 --rx-gain=20_ > > forrx and alsofor uhd\_fft it is printing the same oooooooo continues. > > Thank you. I wouldn’t call the benchmark examples the “very basic.” You still need to understand and calibrate a lot of your system before you can get it to work. If you’re new, you should start with our tutorials: [http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided\_Tutorials](http://gnuradio.org/redmine/projects/gnuradio/wiki/Guided_Tutorials) These will explain a lot of what you’ll be dealing with when you get to this advanced stuff. Tom ---
**Author:** ![alok\_ranjan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/94ad74/32.png) [@alok\_ranjan](https://www.ruby-forum.com/u/alok_ranjan)\ **Post date:** [November 20, 2014, 4:37pm UTC](https://www.ruby-forum.com/t/usrp-1-overflow-problem/233159/3 "2014-11-20T16:37:00Z")
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 1. Tom is absolutely right. Benchmark\_tx is something that illustrates some very interesting aspects of GNU Radio, but it’s not something you start with, because the things you see won’t mean a thing to you. So do the guided tutorials, and if you feel like you’re missing out on some theoretical aspects, maybe pay the “suggested reading” page a visit. 2. Overflows mean that your PC is too slow to keep up with the real time sample processing. Basically, this is nothing that you can solve by doing anything within the “basic” usage of GNU Radio. It just means your machine is too slow. Greetings, Marcus On 11/20/2014 11:32 AM, alok ranjan wrote: > \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Discuss-gnuradio > mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJUbgpFAAoJEAFxB7BbsDrL3SAH/AuKbB52xPpJ5Or39bZ9+2WY VzjV24/O+aLNfmqFzuYd5bK18A11CAZ4elEbHcdtIhTYUVCapZIWTZe0b0d4ZjRz Y0zEEJH+cKQkEpz+7TPcPa6kLsN8rhD7pAhUlSUHMOAcedNWOj5slLlx8+F85c3x YpMRD1L6nZz4gMtNe1KVEEI4vKjZg5kdt5X9ddwQ12KoOyiNv2qGHZyne3OUedwr mO95bXVuZ44iYg4yzSvXF72o/psIlcD3XrmPdMIW0WmTC8Yy41fnLMqp90jCCAjE Y/esA72Moc9PBDhtWLX4YD7dCOADOvDnXcrlfiSRHBNNmSNoLPIIl6GCR+UxbHw= =Q2X1 -----END PGP SIGNATURE----- ---
**Author:** ![alok\_ranjan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/94ad74/32.png) [@alok\_ranjan](https://www.ruby-forum.com/u/alok_ranjan)\ **Post date:** [November 20, 2014, 4:41pm UTC](https://www.ruby-forum.com/t/usrp-1-overflow-problem/233159/4 "2014-11-20T16:41:14Z")
Further, I’m not sure that benchmark\_tx/rx can actually do bit rates as low as 240 bits/second, because the have a fairly-simple symbol-rate model, and the USRP1 can only support sample rates down to 192k. You said that uhd\_fft also produced ‘O’ indications–what parameters were you using with uhd\_fft? On 2014-11-20 10:35, Marcus Müller wrote: > by doing anything within the “basic” usage of GNU Radio. It just means > Version: GnuPG v1 > > * * * > > Discuss-gnuradio mailing list > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) [1] Links: