[Discuss-gnuradio] [patch] usrp_wfm_rcv_nogui.py with pll-tuner

[Patrick Strasser]

Hello!

I've extended the FM-receiver with an option to use the pll tuner.

Without pll my PIII 350Mhz decoded FM mono quite fine, with pll it's 
heavily stuttering.

Patrick

Index: usrp_wfm_rcv_nogui.py
===================================================================
RCS file: 
/sources/gnuradio/gnuradio-examples/python/usrp/usrp_wfm_rcv_nogui.py,v
retrieving revision 1.9
diff -u -r1.9 usrp_wfm_rcv_nogui.py
--- usrp_wfm_rcv_nogui.py       31 Mar 2006 18:33:05 -0000      1.9
+++ usrp_wfm_rcv_nogui.py       23 May 2006 11:08:38 -0000
@@ -34,6 +34,8 @@
                           help="set frequency to FREQ", metavar="FREQ")
         parser.add_option("-g", "--gain", type="eng_float", default=None,
                           help="set gain in dB (default is midpoint)")
+        parser.add_option("-p", "--pll", action="store_true", 
default=False,
+                          help="use the PLL stereo decoder")
         parser.add_option("-O", "--audio-output", type="string", 
default="",
                           help="pcm device name.  E.g., hw:0,0 or 
surround51 or /dev/dsp")

@@ -77,9 +79,14 @@
         #print len(chan_filt_coeffs)
         chan_filt = gr.fir_filter_ccf (chanfilt_decim, chan_filt_coeffs)

-        self.guts = blks.wfm_rcv (self, demod_rate, audio_decimation)
-
+        if options.pll:
+            self.guts = blks.wfm_rcv_pll (self, demod_rate, 
audio_decimation)
+        else:
+            self.guts = blks.wfm_rcv (self, demod_rate, audio_decimation)
+
         self.volume_control = gr.multiply_const_ff(self.vol)
+        self.volume_control_l = gr.multiply_const_ff(self.vol)
+        self.volume_control_r = gr.multiply_const_ff(self.vol)

         # sound card as final sink
         audio_sink = audio.sink(int(audio_rate),
@@ -87,9 +94,13 @@
                                 False)  # ok_to_block

         # now wire it all together
-        self.connect (self.u, chan_filt, self.guts, 
self.volume_control, audio_sink)
-
-
+        self.connect (self.u, chan_filt, self.guts)
+        if options.pll:
+            self.connect ((self.guts, 0), self.volume_control_l, 
(audio_sink,0))
+            self.connect ((self.guts, 1), self.volume_control_r, 
(audio_sink,1))
+        else:
+            self.connect (self.guts, self.volume_control, audio_sink)
+
         if options.gain is None:
             # if no gain was specified, use the mid-point in dB
             g = self.subdev.gain_range()
@@ -108,6 +119,8 @@
     def set_vol (self, vol):
         self.vol = vol
         self.volume_control.set_k(self.vol)
+        self.volume_control_l.set_k(self.vol)
+        self.volume_control_r.set_k(self.vol)
         self.update_status_bar ()

     def set_freq(self, target_freq):

--
Engineers motto: cheap, good, fast: choose any two
Patrick Strasser <patrick dot strasser at  tugraz dot at>
Student of Telematik, Techn. University Graz, Austria