Re: Error in OP25 Decoder block

GNU Radio
1

import op25

I got the prompt right back, no error message.

Right - pretty much as expected. This strongly suggests that the python
code you’re attempting to use (in this case, from gr-baz) has not yet
been forward-ported so as to be compatible with the new GR version 3.7.x
API’s (and with the new op25 version which has been converted to be
compatible with the same). The amount of effort to make it compatible is
a total unknown at this point (assuming the tiny patch to the import
statements isn’t sufficient, that is); Balint would know for certain…

Anyway, to summarize, the test that you ran (above) indicates that the
GR-3.7.x-compatible version of op25 is in fact installed (just not in
the way that gr-baz is looking for it)…

Max

2

I probably overdid the stuff below, but I did try your other suggestion.

I made your change in -
Home/usr/local/lib/python2.7/dist-packages/baz/op25.py

I kept the original stuff in the copyright comments. The lines in your
suggestion above the
_verbose = True line were not in my op25.py.

I noticed in the GRC Welcome statement that this is Version 3.7.5 - I
presume it is the same
as in the 3.7.4 release notice that came out this week.

the Free Software Foundation, Inc., 51 Franklin Street,

Boston, MA 02110-1301, USA.

import math

from gnuradio import gr, gru, op25 as _op25

_verbose = True

import math
from gnuradio import gr, gru
import op25 as _op25

try:
from gnuradio import fsk4 # LEGACY

Here are the results:

<<< Welcome to GNU Radio Companion 3.7.5git-0-g2bb2b314 >>>

Preferences file: /home/doug/.grc
Block paths:
/home/doug/usr/local/share/gnuradio/grc/blocks
/home/doug/.grc_gnuradio

XML parser: Found 1 erroneous XML file while loading the block tree (see
“Help/Parser errors” for details)

Loading: “/home/doug/Documents/Op25 project files/Doug-op25.grc”

Done

Showing: “/home/doug/Documents/Op25 project files/Doug-op25.grc”

Generating: “/home/doug/Documents/Op25 project files/top_block.py”

Executing: “/home/doug/Documents/Op25 project files/top_block.py”

linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.007.001-84-gd99ce4ef

Using Volk machine: sse4_a_64
RTL2832 Source block configuration:
Read length (bytes): 262144
Buffer enabled: yes
Buffer multiplier: 8
Buffer size (samples): 1048576
Samples per read: 131072
Buffer level: 50.0%
Kernel driver detached.
Successfully initialised demod: “ezcap EzTV”
Probing “e4k”…not found.
Probing “fc0013”…not found.
Probing “fc2580”…bad check value.
Probing “r820t”…found.
Found RTL2832 device: ezcap EzTV (tuner: Rafael Micro R820T)
Sample rate range: 900001 - 3200000 Hz
Crystal frequency: 28800000 Hz
[r820t] Initialised (default bandwidth: 0 Hz)
Wait delay: 196.608 ms
Traceback (most recent call last):
File “/home/doug/Documents/Op25 project files/top_block.py”, line
185, in
tb = top_block()
File “/home/doug/Documents/Op25 project files/top_block.py”, line
113, in init
self.op25_decoder_simple_0 = op25.op25_decoder_simple(key=“”,)
File “/home/doug/usr/local/lib/python2.7/dist-packages/baz/op25.py”,
line 98, in init
raise Exception(“Could not find a decoder to use”)
Exception: Could not find a decoder to use
Kernel driver reattached.

Done

Back in early June, near when I started this project, I emailed Balint
from his Spench.net site.
I knew he was having too much fun working on ISEE3, but on July 4, he
sent me the following note:

Hi Doug,
Thanks for your email. Glad to hear you're getting into SDR! Lots of
interesting signals to discover...

That wiki page was actually contributed by someone else, and (as
you've seen) things have changed in OP25 since his instructions were
compiled. I'm not sure what happened to the OP25 build script, but I
put it back. I would suggest that you follow the instructions on the
official OP25 site now though as the build process is different

AFAIK.

  I think you're on the op25-dev mailing list now, so hopefully
you'll be able to get some more answers there. All I can suggest
from here is that as long as you have GNU Radio installed, you
should just be able to either install the OP25 source yourself from
the git repository (and manually satisfy its dependencies) and
build/install, or use the PyBOMBs script to do it all. PyBOMBs will
also install GNU Radio, so if you already have it installed, make
sure you tell PyBOMBs that GNU Radio is already installed (IIRC when
you run it the first time you can tell it what dependencies are
already manually satisfied).

Best place to ask is the list though because I haven't played around
with it in a while
Good luck.
Kind regards,
Balint

I don’t really understand his Pybombs comments, but apparently, he has
moved on.

I presume that all of my grief is because I started out with 3.7
GNURadio , and that a realistic
way to get op25 working is to back off to 3.6. I really don’t want to
do that if there is any other way.

You may have read one of my previous posts on op25-dev where I described
why I am really anxious
to be able to listen to the new Lubbock Harris op25 phase 2 system. I
have talked to two different Lubbock Police officers who have seriously
complained that the audio on their new radios is so bad that they are
unwilling to risk using them. I have a new Uniden BCD 436HP, and the
audio on it is pretty bad.

Thanks very much for your help, Max. Lemmee know if you can think of a
good way out of this.

Doug H.
Lubbock