Creation of a signal generator program
This script takes command line arguments to play signals recorded
into a file. The format of the file should be a raw data file. This
program lets you broadcast multiple signals simultaneously over the
same antennae. Future commits will add a GUI to display the total
signal being broadcasted, addition of parameterized signals. Also
possibly will add the ability to run from a config file as opposed
to command line.
Change-Id: I34bab67e69e057862fa8e84d019cd0a389348b49
diff --git a/signal_generator/README b/signal_generator/README
new file mode 100644
index 0000000..691bbda
--- /dev/null
+++ b/signal_generator/README
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+Signal Generator Script 1.0
+===============================================================================
+This script takes command line arguments to broadcast the sum of various signals
+with differing strengths. The script takes in arguments by specifying a type of
+signal to broadcast followed by the corresponding parameters for that signal.
+This script requires the user to specify at least 1 signal in order to operate.
+In order to broadcast from file, use the '-f' flag and specify the path to the
+file as well as a factor which corresponds to a db-gain on the specific signal.
+A general db-gain can also be specified by using the '-g' flag to amplify the
+combined signal.
+
+Options:
+ -h, --help Show this help message and exit
+ -f FILENAME,FACTOR, --file=FILENAME,FACTOR
+ Add signal from file (raw 64 bit complex) which can be
+ generated using the 'bandpass_recorder.py' script. The
+ raw file can be read using scipy.fromfile.
+ -u FREQUENCY, --frequency=FREQUENCY
+ Specify the desired frequency in KHz, defaults
+ to 2412KHz (Wifi Channel 1)
+ -g DB_GAIN, --gain=DB_GAIN
+ Specify the db-gain amplification, defaults to 50db
+
+Note: If you are playing from a file and are getting Underruns (U), try moving
+the file to local storage.
+
+A set of useful recordings have been placed at "/google/data/rw/teams/gfiber/sdr/recordings"
+that can be used for testing or other purposes.
diff --git a/signal_generator/signal_generator.py b/signal_generator/signal_generator.py
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+++ b/signal_generator/signal_generator.py
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+#!/usr/bin/python
+from optparse import OptionParser
+import sys
+
+from gnuradio import blocks
+from gnuradio import gr
+from gnuradio import uhd
+
+
+class SignalGenerator(gr.top_block):
+
+ def __init__(self):
+ super(SignalGenerator, self).__init__('Signal Generator')
+
+ sample_rate = 30e6
+
+ # Initialize the SDR
+ stream_args = uhd.stream_args(cpu_format='fc32', otw_format='sc8',
+ channels=range(1))
+ self.usrp_sink = uhd.usrp_sink(',', stream_args)
+
+ # Create a list of the file source streams so we can add them as we read
+ # arguments.
+ self.sources = []
+
+ # Adjust parameters
+ self.usrp_sink.set_samp_rate(sample_rate)
+ self.usrp_sink.set_bandwidth(sample_rate)
+
+ # Initialize and connect the signal adder.
+ self.add_block = blocks.add_vcc(1)
+ self.connect((self.add_block, 0), (self.usrp_sink, 0))
+
+ # Adjust gain value on the USRP.
+ def set_gain(self, gain):
+ self.usrp_sink.set_gain(gain)
+
+ # Adjust center frequency value of the USRP.
+ def set_freq(self, freq):
+ self.usrp_sink.set_center_freq(freq, 0)
+
+ # Add a new signal to be broadcasted.
+ def add_file_source(self, filename, factor):
+ # Create and add our file sources paired with their multiplier block to the
+ # sources list.
+ src = blocks.file_source(gr.sizeof_gr_complex, filename, True)
+ multiply_block = blocks.multiply_const_vcc((factor,))
+ self.connect((src, 0), (multiply_block, 0))
+ self.sources.append(multiply_block)
+
+ def run(self):
+ # Connect all the sources to the adder.
+ for i in range(len(self.sources)):
+ self.connect((self.sources[i], 0), (self.add_block, i))
+ gr.top_block.run(self)
+
+if __name__ == '__main__':
+ # Get command line arguments.
+ parser = OptionParser()
+ parser.add_option('-f', '--file', dest='file', help='Add signal from file '
+ '(raw 64 bit complex) which can be generated using the '
+ '\'bandpass_recorder.py\' script. The raw file can be read '
+ 'using scipy.fromfile. If factor is not included, it defaults '
+ 'to 50.0', metavar='FILENAME,FACTOR', action='append')
+ parser.add_option('-u', '--frequency', dest='frequency',
+ help='Specify the desired frequency in KHz, defaults to'
+ '2412000KHz (Wifi Channel 1)', metavar='FREQUENCY',
+ default='2412000')
+ parser.add_option('-g', '--gain', dest='gain',
+ help='Specify the db-gain amplification, defaults to 50db',
+ metavar='DB_GAIN', default='50')
+ options, args = parser.parse_args()
+
+ # Initialize the top_block
+ signal_gen_block = SignalGenerator()
+ signal_gen_block.set_freq(float(options.frequency) * 1000.0)
+ signal_gen_block.set_gain(float(options.gain))
+
+ # Add the signals to the top_block
+ if options.file is not None:
+ for signal in options.file:
+ args = signal.split(',')
+
+ # Check for number of arguments
+ if len(args) > 1:
+ # Verify that the second argument is a float.
+ try:
+ factor = float(args[1])
+ except:
+ print 'Invalid arguments: {0}'.format(signal)
+ sys.exit(1)
+ else:
+ factor = 50.0
+
+ # Add the signal to the top_block.
+ signal_gen_block.add_file_source(args[0], factor)
+ else:
+ print '\nAt least 1 signal is required to run\n'
+ sys.exit(1)
+
+ signal_gen_block.run()
