OP25j

= Questions and Answers =

Do I need a USRP?

The USRP is not essential. You can use sample files collected by others or one of a number of alternative hardware approaches. If you already have a suitable radio receiver you can even interface to it to via your PC's soundcard. Check out the [HardwarePage hardware page] for a short write-up of approaches people are investigating.

How do I install OP25?
At present you can only install OP25 from source. Check the [BuildInstructionsPage build instructions] for details. I have an error in libtool - what's going wrong?
I run the ./bootstrap and ./configure commands succesfuly but the make command failed with the following error: {{{
libtool:Version mismatch error. This is libtool 2.2.4, but the definition of this LT_INIT comes from an older release. You should recreate aclocal.m4 with macros from libtool 2.2.4 and run auto conf again.
}}}
The aclocal.m4 file is auto-generated as a result of running the 'bootstrap' script that comes with the tarball. It is safe to delete 'aclocal.m4' - bootstrap will re-create it. The usual routine is to run the following after un-tarring the tarball - {{{
./bootstrap
./configure
make
make install
}}}
If you've made other changes in the middle of this process, such as installing new stuff, it might be best to always re-start at the first of these steps (bootstrap)... The self-test doesn't work

When I try the python self-test programs I get something like this:-

{{{
./qa_fsk4.py
Traceback (most recent call last):
File "./qa_fsk4.py", line 24, in <module>
import fsk4
ImportError: No module named fsk4
}}}

This occurs because you aren't meant to run qa_fsk4.py or qa_op25.py directly. Instead you should run "make check" from the block's top-level directory.

When I run usrp_p25_rx.py the user interface is unresponsive
The receiver consumes a significant amount of CPU and I/O bandwidth. If you have a slow computer and are trying to receive/play very wideband captures then there maybe little left to do anything else. Try using a lower sampling rate (a higher decimation factor) to see how much bandwidth your computer can process. Also you can install the "System Monitor" applet into your task bar which gives a good visual indication of how heavily loaded your CPU is.

In the last last analysis you can use the GNURadio usrp_rx_cfile.py example program to capture sample files at the command line but you will always be limited by CPU and I/O bandwidth as to how much spectrum you can sample at any one time.

Why are you guys so s-l-o-w?

Well, we're a part-time hobby effort by a couple of enthusiasts. If you want to speed us up please feel free to help.

How can I help?

We're looking for help with coding, testing, providing advice, gathering sample data, writing documentation or providing hardware. Whatever you can volunteer is welcome.