gnuradio-fm-radio-receiver/fm_radio.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

#
# SPDX-License-Identifier: GPL-3.0
#
# GNU Radio Python Flow Graph
# Title: FM Radio Receiver
# GNU Radio version: 3.10.5.1

from gnuradio import analog
from gnuradio import audio
from gnuradio import filter
from gnuradio.filter import firdes
from gnuradio import gr
from gnuradio.fft import window
import sys
import signal
from argparse import ArgumentParser
from gnuradio.eng_arg import eng_float, intx
from gnuradio import eng_notation
import osmosdr
import time


class fm_radio(gr.top_block):
    def __init__(self):
        gr.top_block.__init__(self, "FM Radio Receiver", catch_exceptions=True)

        ##################################################
        # Variables
        ##################################################
        self.samp_rate = samp_rate = 2560000
        self.channel_width_hertz = channel_width_hertz = 250000
        self.audio_sample_rate_hertz = audio_sample_rate_hertz = 48000

        ##################################################
        # Blocks
        ##################################################

        self.rtlsdr_source_0 = osmosdr.source(args="numchan=" + str(1) + " " + "")
        self.rtlsdr_source_0.set_time_unknown_pps(osmosdr.time_spec_t())
        self.rtlsdr_source_0.set_sample_rate(samp_rate)
        self.rtlsdr_source_0.set_center_freq((98.3 * 1e6), 0)
        self.rtlsdr_source_0.set_freq_corr(0, 0)
        self.rtlsdr_source_0.set_dc_offset_mode(0, 0)
        self.rtlsdr_source_0.set_iq_balance_mode(0, 0)
        self.rtlsdr_source_0.set_gain_mode(False, 0)
        self.rtlsdr_source_0.set_gain(20, 0)
        self.rtlsdr_source_0.set_if_gain(20, 0)
        self.rtlsdr_source_0.set_bb_gain(20, 0)
        self.rtlsdr_source_0.set_antenna("", 0)
        self.rtlsdr_source_0.set_bandwidth(0, 0)
        self.rational_resampler_xxx_0 = filter.rational_resampler_fff(
            interpolation=audio_sample_rate_hertz,
            decimation=channel_width_hertz,
            taps=[],
            fractional_bw=0,
        )
        self.low_pass_filter_0 = filter.fir_filter_ccf(
            (int(samp_rate / channel_width_hertz)),
            firdes.low_pass(2, samp_rate, 100000, 10000, window.WIN_KAISER, 6.76),
        )
        self.audio_sink_0 = audio.sink(audio_sample_rate_hertz, "", True)
        self.analog_wfm_rcv_0 = analog.wfm_rcv(
            quad_rate=channel_width_hertz,
            audio_decimation=1,
        )

        ##################################################
        # Connections
        ##################################################
        self.connect((self.analog_wfm_rcv_0, 0), (self.rational_resampler_xxx_0, 0))
        self.connect((self.low_pass_filter_0, 0), (self.analog_wfm_rcv_0, 0))
        self.connect((self.rational_resampler_xxx_0, 0), (self.audio_sink_0, 0))
        self.connect((self.rtlsdr_source_0, 0), (self.low_pass_filter_0, 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(2, self.samp_rate, 100000, 10000, window.WIN_KAISER, 6.76)
        )
        self.rtlsdr_source_0.set_sample_rate(self.samp_rate)

    def get_channel_width_hertz(self):
        return self.channel_width_hertz

    def set_channel_width_hertz(self, channel_width_hertz):
        self.channel_width_hertz = channel_width_hertz

    def get_audio_sample_rate_hertz(self):
        return self.audio_sample_rate_hertz

    def set_audio_sample_rate_hertz(self, audio_sample_rate_hertz):
        self.audio_sample_rate_hertz = audio_sample_rate_hertz


def main(top_block_cls=fm_radio, options=None):
    tb = top_block_cls()

    def sig_handler(sig=None, frame=None):
        tb.stop()
        tb.wait()

        sys.exit(0)

    signal.signal(signal.SIGINT, sig_handler)
    signal.signal(signal.SIGTERM, sig_handler)

    tb.start()

    try:
        input("Press Enter to quit: ")
    except EOFError:
        pass
    tb.stop()
    tb.wait()


if __name__ == "__main__":
    main()