Re: [Discuss-gnuradio] Having issues getting APT-DECODER Sample working

[Patrik Tast]

You will have to investigate more.

Try download/build the
<http://www.qsl.net/5b4az/pkg/apt/wxapt/wxapt.html> or (I use)
<http://atpdec.sourceforge.net/>

It shouldn't be that hard...

Patrik




On Sun, 2012-10-07 at 18:31 -0400, Tommy James Tracy II wrote:
> On 10/7/12 4:24 PM, Patrik Tast wrote:
> > Hi Tommy,
> > 
> >> and opened it in the file source, and ran the gnuradio program. If I do
> >> a cat of the output.dat file, I found that there was nothing in it. I
> >> then opened it in VIM and found the following string repeated:
> >>
> >> "address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@^@"
> >>
> >> I think those aren't valid characters so maybe the float_to_uchar was
> >> unsuccessful.
> >>
> >> Did you use a different algorithm? Do I need to multiply the input to
> >> fit it between the 0->1v range before the 255 multiplier?
> >>
> > 
> > oooh...I suspect that you have something set wrong now?
> > I can not understand what you are doing.
> >
> 
> 
> I have attached an image of my GRC flowgraph. It is meant to be an exact
> copy of the one presented at the following website:
> http://www.oz9aec.net/index.php/gnu-radio/gnu-radio-blog/440-simple-apt-decoder-prototype
> 
> I have either made a mistake, the website has a non-functional flowgraph
> on it, or the input WAV file is incorrect; I think you verified the WAV
> file.. so i think it is one of the first two.
> 
> > To test I downloaded
> > http://www.poes-weather.com/~patrik/apt/audio/24_June_2009/090724_032529_NOAA_18.wav
> > 
> > Screenshot while decoding using my software
> > http://poes-weather.com/~patrik/tmp/Screenshot%20from%202012-10-07%
> > 2023:08:09.png
> 
> From the looks of the screenshot you sent, you are using a different
> application. Do you use Gnuradio under the hood?
> 
> > 
> > This should be decodable using any software. 
> > I suspect you are on the wrong track now.
> > 
> > Patrik
> 
> Thanks again,
> Tom
> > 
> > 
> > 
> > On Sun, 2012-10-07 at 13:26 -0400, Tommy James Tracy II wrote:
> >> On 10/7/12 6:44 AM, Patrik Tast wrote:
> >>> Hi Tommy,
> >>>
> >>>> What do you mean by source file sink?
> >>> I thought you were using GRC and if the file was downloaded from me I
> >>> know it is (recorded) in 8bit 2.4kHz carrier.
> >>>
> >>> You will find a lot of hits regarding APT when googling and be very
> >>> objective, most are copy -> copy....
> >>>
> >>> Sure we can/could convert it to 16, 32, 64, 128 bit etc.
> >>> The fact is that APT is 8bit so why change it to 32bit?
> >>> The result will be a 4x bigger file almost full of zeroes since again
> >>> only 8 bits are used (gray scale). If recorded as 16bit it will be of
> >>> course 2x bigger than required since max is again 0x0000 ffff.
> >>> In this case you wont win if more bits are used.
> >>>
> >>> APT bandwidth is ~30kHz @ 137Mhz
> >>>
> >>> Some samples here, don't convert:
> >>> http://www.poes-weather.com/~patrik/apt/audio/24_June_2009/
> >>> Images & tests:
> >>> http://www.poes-weather.com/index.php?view=article&id=100%
> >>> 3Asunday-6th-july-2008&Itemid=73&option=com_content
> >>>
> >>> 24/7 images:
> >>> http://www.poes-weather.com/~patrik/apt/logs/daily/
> >>
> >> Thank you for the reply; I took one of your 8bit samples:
> >>  
> >> www.poes-weather.com/~patrik/apt/audio/24_June_2009/090723_213010_NOAA_17.wav
> >>
> >> and opened it in the file source, and ran the gnuradio program. If I do
> >> a cat of the output.dat file, I found that there was nothing in it. I
> >> then opened it in VIM and found the following string repeated:
> >>
> >> "address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@address@hidden@^@"
> >>
> >> I think those aren't valid characters so maybe the float_to_uchar was
> >> unsuccessful.
> >>
> >> Did you use a different algorithm? Do I need to multiply the input to
> >> fit it between the 0->1v range before the 255 multiplier?
> >>
> >> Sincerely,
> >> Tommy Tracy II
> >>
> >>>
> >>> Patrik
> >>>
> >>> On Sat, 2012-10-06 at 22:43 -0400, Tommy James Tracy II wrote:
> >>>> On 10/6/12 5:37 PM, Patrik Tast wrote:
> >>>>> Hi Tommy,
> >>>>>
> >>>>> Most likely the file (wav) you have found is in 8bit.
> >>>>> Try to adjust your source file sink.
> >>>>>
> >>>>> Patrik
> >>>>>
> >>>> Dear Patrik,
> >>>>
> >>>>  What do you mean by source file sink?
> >>>> I used soundconverter to convert the WAV file to mp3, and then back to a
> >>>> 32-bit sampled WAV. I tried it, and it failed with the same error.
> >>>>
> >>>> I also tried to use FFT with byte input, but that doesn't exist. The
> >>>> only options are float or complex.
> >>>>
> >>>> Again thank you!
> >>>>
> >>>> Tom
> >>>>
> >>>>> On Sat, 2012-10-06 at 16:51 -0400, Tommy James Tracy II wrote:
> >>>>>> Dear Gnuradio,
> >>>>>>
> >>>>>>        I'm trying to run the following gnuradio program:
> >>>>>> http://www.oz9aec.net/index.php/gnu-radio/gnu-radio-blog/440-simple-apt-decoder-prototype
> >>>>>>
> >>>>>> I found a WAV file online to use as the input to the APT-Decoder, so I
> >>>>>> fed it in. Unfortunately, the output file resulted in a bunch of '^@'
> >>>>>> characters instead of the expected ASCII(0) through ASCII(255).
> >>>>>>
> >>>>>> To make sure that the Audio file source was actually producing an
> >>>>>> output, I hooked up an AUDIO_SINK block between the File Source and the
> >>>>>> Band Pass Filter. I heard the expected APT sound.
> >>>>>>
> >>>>>> I then proceeded to drop in a WX GUI FFT Sink, and kept getting the
> >>>>>> following error:
> >>>>>>
> >>>>>> Has anyone seen this?
> >>>>>> -----
> >>>>>>
> >>>>>> Traceback (most recent call last):
> >>>>>>   File
> >>>>>> "/usr/local/lib/python2.7/dist-packages/gnuradio/wxgui/plotter/plotter_base.py",
> >>>>>> line 187, in _on_paint
> >>>>>>     for fcn in self._draw_fcns: fcn[1]()
> >>>>>>   File
> >>>>>> "/usr/local/lib/python2.7/dist-packages/gnuradio/wxgui/plotter/plotter_base.py",
> >>>>>> line 59, in draw
> >>>>>>     self._draw()
> >>>>>>   File
> >>>>>> "/usr/local/lib/python2.7/dist-packages/gnuradio/wxgui/plotter/grid_plotter_base.py",
> >>>>>> line 407, in _draw_point_label
> >>>>>>     label_str = self._populate_point_label(x_val, y_val)
> >>>>>>   File
> >>>>>> "/usr/local/lib/python2.7/dist-packages/gnuradio/wxgui/plotter/channel_plotter.py",
> >>>>>> line 151, in _populate_point_label
> >>>>>>     label_str += '\n%s: %s'%(channel, common.eng_format(y_value,
> >>>>>> self.y_units))
> >>>>>>   File
> >>>>>> "/usr/local/lib/python2.7/dist-packages/gnuradio/wxgui/plotter/common.py",
> >>>>>> line 82, in eng_format
> >>>>>>     coeff, exp, prefix = get_si_components(num)
> >>>>>>   File
> >>>>>> "/usr/local/lib/python2.7/dist-packages/gnuradio/wxgui/plotter/common.py",
> >>>>>> line 48, in get_si_components
> >>>>>>     exp = get_exp(num)
> >>>>>>   File
> >>>>>> "/usr/local/lib/python2.7/dist-packages/gnuradio/wxgui/plotter/common.py",
> >>>>>> line 37, in get_exp
> >>>>>>     return int(math.floor(math.log10(abs(num))))
> >>>>>> ValueError: cannot convert float NaN to integer
> >>>>>>
> >>>>>> -----
> >>>>>>
> >>>>>> I think this means that the WAV file (float output) is producing NAN
> >>>>>> outputs. Is there any way that I can remove those? Anyone have any
> >>>>>> success doing this before?
> >>>>>>
> >>>>>> Thanks in advance!
> >>>>>> _______________________________________________
> >>>>>> Discuss-gnuradio mailing list
> >>>>>> address@hidden
> >>>>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >>>>>
> >>>>>
> >>>>>
> >>>>> _______________________________________________
> >>>>> Discuss-gnuradio mailing list
> >>>>> address@hidden
> >>>>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >>>>>
> >>>>
> >>>>
> >>>
> >>>
> >>
> >>
> > 
> > 
> 
>