signal_generator/signal_generator.py

#!/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()