FM Receiver with GNU Radio Python Code

FM Receiver

if __name__ == '__main__':
    import ctypes
    import sys
    if sys.platform.startswith('linux'):
        try:
            x11 = ctypes.cdll.LoadLibrary('libX11.so')
            x11.XInitThreads()
        except:
            print "Warning: failed to XInitThreads()"

from gnuradio import analog
from gnuradio import audio
from gnuradio import eng_notation
from gnuradio import filter
from gnuradio import gr
from gnuradio import uhd
from gnuradio import wxgui
from gnuradio.eng_option import eng_option
from gnuradio.fft import window
from gnuradio.filter import firdes
from gnuradio.wxgui import fftsink2
from gnuradio.wxgui import forms
from gnuradio.wxgui import scopesink2
from grc_gnuradio import wxgui as grc_wxgui
from optparse import OptionParser
import time
import wx


class top_block(grc_wxgui.top_block_gui):

    def __init__(self):
        grc_wxgui.top_block_gui.__init__(self, title="Top Block")
        _icon_path = "C:\Program Files\GNURadio-3.7\share\icons\hicolor\48x48/apps\gnuradio-grc.png"
        self.SetIcon(wx.Icon(_icon_path, wx.BITMAP_TYPE_ANY))

        ##################################################
        # Variables
        ##################################################
        self.samp_rate = samp_rate = 4000000
        self.freq = freq = 99900000

        ##################################################
        # Blocks
        ##################################################
        self.notebook = self.notebook = wx.Notebook(self.GetWin(), style=wx.NB_TOP)
        self.notebook.AddPage(grc_wxgui.Panel(self.notebook), "tab1")
        self.notebook.AddPage(grc_wxgui.Panel(self.notebook), "tab2")
        self.Add(self.notebook)
        _freq_sizer = wx.BoxSizer(wx.VERTICAL)
        self._freq_text_box = forms.text_box(
        parent=self.GetWin(),
        sizer=_freq_sizer,
        value=self.freq,
        callback=self.set_freq,
        label='freq',
        converter=forms.float_converter(),
        proportion=0,
        )
        self._freq_slider = forms.slider(
        parent=self.GetWin(),
        sizer=_freq_sizer,
        value=self.freq,
        callback=self.set_freq,
        minimum=95000000,
        maximum=108000000,
        num_steps=1000,
        style=wx.SL_VERTICAL,
        cast=float,
        proportion=1,
        )
        self.Add(_freq_sizer)
        self.wxgui_scopesink2_0 = scopesink2.scope_sink_f(
        self.notebook.GetPage(1).GetWin(),
        title="Output ",
        sample_rate=samp_rate,
        v_scale=0,
        v_offset=0,
        t_scale=0,
        ac_couple=False,
        xy_mode=False,
        num_inputs=1,
        trig_mode=wxgui.TRIG_MODE_AUTO,
        y_axis_label="Counts",
        )
        self.notebook.GetPage(1).Add(self.wxgui_scopesink2_0.win)
        self.wxgui_fftsink2_1 = fftsink2.fft_sink_c(
        self.notebook.GetPage(0).GetWin(),
        baseband_freq=0,
        y_per_div=10,
        y_divs=10,
        ref_level=0,
        ref_scale=2.0,
        sample_rate=samp_rate,
        fft_size=1024,
        fft_rate=15,
        average=True,
        avg_alpha=None,
        title="Channel",
        peak_hold=False,
        )
        self.notebook.GetPage(0).Add(self.wxgui_fftsink2_1.win)
        self.uhd_usrp_source_0 = uhd.usrp_source(
        ",".join(("", "")),
        uhd.stream_args(
        cpu_format="fc32",
        channels=range(1),
        ),
        )
        self.uhd_usrp_source_0.set_samp_rate(samp_rate)
        self.uhd_usrp_source_0.set_center_freq(freq, 0)
        self.uhd_usrp_source_0.set_gain(50, 0)
        self.uhd_usrp_source_0.set_antenna("RX2", 0)
        self.rational_resampler_xxx_0 = filter.rational_resampler_ccf(
                interpolation=192000,
                decimation=200000,
                taps=None,
                fractional_bw=None,
        )
        self.low_pass_filter_0 = filter.fir_filter_ccf(20, firdes.low_pass(
        1, samp_rate, 100000, 10e3, firdes.WIN_HAMMING, 6.76))
        self.audio_sink_0 = audio.sink(96000, "", True)
        self.analog_wfm_rcv_0 = analog.wfm_rcv(
        quad_rate=192000,
        audio_decimation=2,
        )

        ##################################################
        # Connections
        ##################################################
        self.connect((self.analog_wfm_rcv_0, 0), (self.audio_sink_0, 0))  
        self.connect((self.analog_wfm_rcv_0, 0), (self.wxgui_scopesink2_0, 0))  
        self.connect((self.low_pass_filter_0, 0), (self.rational_resampler_xxx_0, 0))  
        self.connect((self.rational_resampler_xxx_0, 0), (self.analog_wfm_rcv_0, 0))  
        self.connect((self.uhd_usrp_source_0, 0), (self.low_pass_filter_0, 0))  
        self.connect((self.uhd_usrp_source_0, 0), (self.wxgui_fftsink2_1, 0))  

    def get_samp_rate(self):
        return self.samp_rate

    def set_samp_rate(self, samp_rate):
        self.samp_rate = samp_rate
        self.low_pass_filter_0.set_taps(firdes.low_pass(1, self.samp_rate, 100000, 10e3, firdes.WIN_HAMMING, 6.76))
        self.uhd_usrp_source_0.set_samp_rate(self.samp_rate)
        self.wxgui_fftsink2_1.set_sample_rate(self.samp_rate)
        self.wxgui_scopesink2_0.set_sample_rate(self.samp_rate)

    def get_freq(self):
        return self.freq

    def set_freq(self, freq):
        self.freq = freq
        self._freq_slider.set_value(self.freq)
        self._freq_text_box.set_value(self.freq)
        self.uhd_usrp_source_0.set_center_freq(self.freq, 0)


def main(top_block_cls=top_block, options=None):

    tb = top_block_cls()
    tb.Start(True)
    tb.Wait()


if __name__ == '__main__':

    main()