Re: [Discuss-gnuradio] Simple Broadcast FM Receiver

[Martin Dvh]

Muhammad Abrar wrote:
> Now I run this program n my Laptop on whicg gnuradi 3.0.4-2ubuntu2  is
> installed and i get following message.
> 
> address@hidden:~/Documents/usrp$ python usrp_wfm_rcv_pll.py
>>>> gr_fir_ccf: using SSE
>>>> gr_fir_fff: using SSE
>>>> gr_fir_fcc: using SSE
> audio_alsa_sink[hw:0,0]: unable to support sampling rate 32000
>   card requested 44100 instead.
> FYI: This implementation of the stereo_carrier_pll_recovery has no
> squelch implementation yet
> FYI: No Powermate or Contour Knob found
> FYI: This implementation of the stereo_carrier_pll_recovery has no
> squelch implementation yet
> address@hidden:~/Documents/usrp$
> 
> 


> audio_alsa_sink[hw:0,0]: unable to support sampling rate 32000
>   card requested 44100 instead.
This means the your audio_card does not support 32000 Hz samplerate.
So you get Audio Underruns  (aU)
This can be solved by using the commandline parameter
-O plughw:0,0

This will use the alsa software resampler to resample the 32000  to 44100

Please use reply-to-all when using the mailinglist.
Now I was the only one who got your reply, and not the mailinglist.

Greetings,
Martin
> 
> 2009/1/27 Martin DvH <address@hidden
> <mailto:address@hidden>>
> 
> 
>     On Mon, 2009-01-26 at 17:04 +1300, Muhammad Abrar wrote:
>     > when i run this program ithe following ewrror appears, how can i
>     resolve this.
>     > Nameerror: microtune_eval_board is not defined at line 70:
>     >
>     > #!/usr/bin/env python
>     >
>     > # simple broadcast FM receiver
>     >
>     >
>     > from GnuRadio import *
>     >
>     > #
>     > # return a gr_FlowGraph
>     > #
>     > def build_graph (IF_freq):
>     >     input_rate = 20e6
>     >
>     >     CFIR_decimate = 125
>     >     RFIR_decimate = 5
>     >     fm_demod_gain = 2200
>     >
>     >     quad_rate = input_rate / CFIR_decimate
>     >
>     >     audio_rate = quad_rate / RFIR_decimate
>     >
>     >     volume = 1.0
>     >
>     >     src = GrHighSpeedADCSourceS (input_rate)
>     >
>     >     # compute FIR filter taps for channel selection
>     >     channel_coeffs = \
>     >       gr_firdes.low_pass (
>     >
>     >         1.0,          # gain
>     >         input_rate,   # sampling rate
>     >         250e3,        # low pass cutoff freq
>     >         8*100e3,      # width of trans. band
>     >         gr_firdes.WIN_HAMMING)
>     >
>     >     # input: short; output: complex
>     >
>     >     chan_filter = \
>     >       GrFreqXlatingFIRfilterSCF (CFIR_decimate,
>     >                                  channel_coeffs,
>     >                                  IF_freq)
>     >     # input: complex; output: float
>     >     fm_demod = \
>     >
>     >       GrQuadratureDemodCF (volume * fm_demod_gain)
>     >
>     >     # compute FIR filter taps for audio filter
>     >     width_of_transition_band = audio_rate / 32
>     >     audio_coeffs = \
>     >       gr_firdes.low_pass (
>     >         1.0,            # gain
>     >
>     >         quad_rate,      # sampling rate
>     >         audio_rate/2 - width_of_transition_band,
>     >         width_of_transition_band,
>     >         gr_firdes.WIN_HAMMING)
>     >
>     >     # input: float; output: short
>     >     audio_filter = \
>     >
>     >       GrFIRfilterFSF (RFIR_decimate, audio_coeffs)
>     >
>     >     final_sink = GrAudioSinkS ()
>     >
>     >     fg = gr_FlowGraph ()
>     >
>     >     fg.connect (src, chan_filter)
>     >     fg.connect (chan_filter, fm_demod)
>     >     fg.connect (fm_demod, audio_filter)
>     >
>     >     fg.connect (audio_filter, final_sink)
>     >
>     >     return fg
>     >
>     > if __name__ == '__main__':
>     >
>     >     # connect to RF front end
>     >     rf_front_end = microtune_eval_board ()
>     >     if not rf_front_end.board_present_p ():
>     >
>     >         raise IOError, 'RF front end not found'
>     >
>     >     # set gain and radio station frequency
>     >     rf_front_end.set_AGC (300)
>     >     rf_front_end.set_RF_freq (100.1e6)
>     >
>     >     IF_freq = rf_front_end.get_output_freq ()
>     >
>     >     fg = build_graph (IF_freq)
>     >     fg.start ()        # fork thread(s) and return
>     >     raw_input ('Press Enter to quit: ')
>     >     fg.stop ()
>     >
>     >
>     You are using a very very old version of gnuradio.
>     Please update to the current tarball or svn code:
>     http://gnuradio.org/trac/wiki/Download
>     http://gnuradio.org/trac/wiki/GettingStarted
> 
>     Greetings,
>     Martin
>     > --
>     > Engr. Muhammad Abrar
>     > NewZealand
>     > Mob: 0064211204202
>     > Res: 006463586340
>     > _______________________________________________
>     > Discuss-gnuradio mailing list
>     > address@hidden <mailto:address@hidden>
>     > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> 
> 
> 
> 
> -- 
> Engr. Muhammad Abrar
> Massey University Palmerston North
> NewZealand
> Mob: 0064211204202
> Res: 006463586340