Houston, we have a trunk.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@3122 221aa14e-8319-0410-a670-987f0aec2ac5

1 files changed, 171 insertions, 0 deletions

diff --git a/gnuradio-examples/python/usrp/fm_tx4.py b/gnuradio-examples/python/usrp/fm_tx4.py
new file mode 100755
index 000000000..a9201b3f4
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+++ b/gnuradio-examples/python/usrp/fm_tx4.py
@@ -0,0 +1,171 @@
+#!/usr/bin/env python
+
+"""
+Transmit N simultaneous narrow band FM signals.
+
+They will be centered at the frequency specified on the command line,
+and will spaced at 25kHz steps from there.
+
+The program opens N files with names audio-N.dat where N is in [0,7].
+These files should contain floating point audio samples in the range [-1,1]
+sampled at 32kS/sec.  You can create files like this using
+audio_to_file.py
+"""
+
+from gnuradio import gr, eng_notation
+from gnuradio import usrp
+from gnuradio import audio
+from gnuradio import blks
+from gnuradio.eng_option import eng_option
+from optparse import OptionParser
+import usrp_dbid
+import math
+import sys
+
+from gnuradio.wxgui import stdgui, fftsink
+from gnuradio import tx_debug_gui
+import wx
+
+
+########################################################
+# instantiate one transmit chain for each call
+
+class pipeline(gr.hier_block):
+    def __init__(self, fg, filename, lo_freq, audio_rate, if_rate):
+
+        src = gr.file_source (gr.sizeof_float, filename, True)
+        fmtx = blks.nbfm_tx (fg, audio_rate, if_rate,
+                             max_dev=5e3, tau=75e-6)
+        
+        # Local oscillator
+        lo = gr.sig_source_c (if_rate,        # sample rate
+                              gr.GR_SIN_WAVE, # waveform type
+                              lo_freq,        #frequency
+                              1.0,            # amplitude
+                              0)              # DC Offset
+        mixer = gr.multiply_cc ()
+    
+        fg.connect (src, fmtx, (mixer, 0))
+        fg.connect (lo, (mixer, 1))
+
+        gr.hier_block.__init__(self, fg, src, mixer)
+
+
+
+class fm_tx_graph (stdgui.gui_flow_graph):
+    def __init__(self, frame, panel, vbox, argv):
+        MAX_CHANNELS = 7
+        stdgui.gui_flow_graph.__init__ (self, frame, panel, vbox, argv)
+
+        parser = OptionParser (option_class=eng_option)
+        parser.add_option("-T", "--tx-subdev-spec", type="subdev", default=None,
+                          help="select USRP Tx side A or B")
+        parser.add_option("-f", "--freq", type="eng_float", default=None,
+                           help="set Tx frequency to FREQ [required]", metavar="FREQ")
+        parser.add_option("-n", "--nchannels", type="int", default=4,
+                           help="number of Tx channels [1,4]")
+        parser.add_option("","--debug", action="store_true", default=False,
+                          help="Launch Tx debugger")
+        (options, args) = parser.parse_args ()
+
+        if len(args) != 0:
+            parser.print_help()
+            sys.exit(1)
+
+        if options.nchannels < 1 or options.nchannels > MAX_CHANNELS:
+            sys.stderr.write ("fm_tx4: nchannels out of range.  Must be in [1,%d]\n" % MAX_CHANNELS)
+            sys.exit(1)
+        
+        if options.freq is None:
+            sys.stderr.write("fm_tx4: must specify frequency with -f FREQ\n")
+            parser.print_help()
+            sys.exit(1)
+
+        # ----------------------------------------------------------------
+        # Set up constants and parameters
+
+        self.u = usrp.sink_c ()       # the USRP sink (consumes samples)
+
+        self.dac_rate = self.u.dac_rate()                    # 128 MS/s
+        self.usrp_interp = 400
+        self.u.set_interp_rate(self.usrp_interp)
+        self.usrp_rate = self.dac_rate / self.usrp_interp    # 320 kS/s
+        self.sw_interp = 10
+        self.audio_rate = self.usrp_rate / self.sw_interp    # 32 kS/s
+
+        # determine the daughterboard subdevice we're using
+        if options.tx_subdev_spec is None:
+            options.tx_subdev_spec = usrp.pick_tx_subdevice(self.u)
+
+        m = usrp.determine_tx_mux_value(self.u, options.tx_subdev_spec)
+        #print "mux = %#04x" % (m,)
+        self.u.set_mux(m)
+        self.subdev = usrp.selected_subdev(self.u, options.tx_subdev_spec)
+        print "Using TX d'board %s" % (self.subdev.side_and_name(),)
+
+        self.subdev.set_gain(self.subdev.gain_range()[1])    # set max Tx gain
+        self.set_freq(options.freq)
+        self.subdev.set_enable(True)                         # enable transmitter
+
+        sum = gr.add_cc ()
+
+        # Instantiate N NBFM channels
+        step = 25e3
+        offset = (0 * step, 1 * step, -1 * step, 2 * step, -2 * step, 3 * step, -3 * step)
+        for i in range (options.nchannels):
+            t = pipeline (self, "audio-%d.dat" % (i % 4), offset[i],
+                          self.audio_rate, self.usrp_rate)
+            self.connect (t, (sum, i))
+
+        gain = gr.multiply_const_cc (4000.0 / options.nchannels)
+
+        # connect it all
+        self.connect (sum, gain)
+        self.connect (gain, self.u)
+
+        # plot an FFT to verify we are sending what we want
+        if 1:
+            post_mod = fftsink.fft_sink_c(self, panel, title="Post Modulation",
+                                          fft_size=512, sample_rate=self.usrp_rate,
+                                          y_per_div=20, ref_level=40)
+            self.connect (sum, post_mod)
+            vbox.Add (post_mod.win, 1, wx.EXPAND)
+            
+
+        if options.debug:
+            self.debugger = tx_debug_gui.tx_debug_gui(self.subdev)
+            self.debugger.Show(True)
+
+
+    def set_freq(self, target_freq):
+        """
+        Set the center frequency we're interested in.
+
+        @param target_freq: frequency in Hz
+        @rypte: bool
+
+        Tuning is a two step process.  First we ask the front-end to
+        tune as close to the desired frequency as it can.  Then we use
+        the result of that operation and our target_frequency to
+        determine the value for the digital up converter.  Finally, we feed
+        any residual_freq to the s/w freq translater.
+        """
+
+        r = self.u.tune(self.subdev._which, self.subdev, target_freq)
+        if r:
+            print "r.baseband_freq =", eng_notation.num_to_str(r.baseband_freq)
+            print "r.dxc_freq      =", eng_notation.num_to_str(r.dxc_freq)
+            print "r.residual_freq =", eng_notation.num_to_str(r.residual_freq)
+            print "r.inverted      =", r.inverted
+            
+            # Could use residual_freq in s/w freq translator
+            return True
+
+        return False
+
+def main ():
+    app = stdgui.stdapp (fm_tx_graph, "Multichannel FM Tx")
+    app.MainLoop ()
+
+if __name__ == '__main__':
+    main ()