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Diffstat (limited to 'gnuradio-examples/python/dect/usrp_source.py')
| -rw-r--r-- | gnuradio-examples/python/dect/usrp_source.py | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/gnuradio-examples/python/dect/usrp_source.py b/gnuradio-examples/python/dect/usrp_source.py new file mode 100644 index 000000000..6a779840f --- /dev/null +++ b/gnuradio-examples/python/dect/usrp_source.py @@ -0,0 +1,124 @@ +#!/usr/bin/env python +# +# Copyright 2007 Free Software Foundation, Inc. +# +# This file is part of GNU Radio +# +# GNU Radio is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3, or (at your option) +# any later version. +# +# GNU Radio is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +from gnuradio import gr, usrp, eng_notation +n2s = eng_notation.num_to_str + +# Hierarchical block implementing a USRP source for complex floats, +# with convenience functions for gain, tune, decimation, etc. +# +class usrp_source_c(gr.hier_block2): + """ + Create a USRP source object supplying complex floats. + """ + def __init__(self, which=0, subdev_spec=None, gain=None, if_rate=None, + freq=0.0, calibration=0.0, verbose=False): + # Call hierarchical block constructor + gr.hier_block2.__init__(self, + "usrp_source_c", # Block typename + gr.io_signature(0,0,0), # Input signature + gr.io_signature(1,1,gr.sizeof_gr_complex)) # Output signature + + self._verbose = verbose + self._u = usrp.source_c(which) + if self._verbose: + print 'ADC sample rate is', n2s(self._u.adc_rate()), "sps" + self.set_subdev(subdev_spec) + self.set_if_rate(if_rate) + self.set_gain(gain) + self.set_calibration(calibration) + self.tune(freq) + self.connect(self._u, self) + + def set_subdev(self, subdev_spec): + if subdev_spec is None: + subdev_spec = self.pick_subdevice() + self._subdev = usrp.selected_subdev(self._u, subdev_spec) + self._u.set_mux(usrp.determine_rx_mux_value(self._u, subdev_spec)) + if self._verbose: + print 'RX using', self._subdev.name(), 'daughterboard' + + def pick_subdevice(self): + """ + The user didn't specify a subdevice. + If there's a daughterboard on A, select A. + If there's a daughterboard on B, select B. + Otherwise, select A. + """ + if self._u.db[0][0].dbid() >= 0: # dbid is < 0 if there's no d'board or a problem + return (0, 0) + if self._u.db[1][0].dbid() >= 0: + return (1, 0) + return (0, 0) + + def set_if_rate(self, if_rate): + # If no IF rate specified, set to maximum decimation + if if_rate is None: + self._decim = 256 + else: + self._decim = int(self._u.adc_rate()/if_rate) + + self._u.set_decim_rate(self._decim) + self._if_rate = self._u.adc_rate()/self._decim + + if self._verbose: + print "USRP decimation rate is", self._decim + print "USRP IF rate is", n2s(self._if_rate), "sps" + + def set_gain(self, gain): + # If no gain specified, set to midrange + if gain is None: + g = self._subdev.gain_range() + gain = (g[0]+g[1])/2.0 + self._gain = gain + self._subdev.set_gain(self._gain) + + def set_calibration(self, calibration): + self._cal = calibration + if self._verbose: + print "Using frequency calibration offset of", n2s(calibration), "Hz" + + def tune(self, freq): + """ + Set the center frequency we're interested in. + + @param target_freq: frequency in Hz + @type: 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 down converter. + """ + self._tune_result = usrp.tune(self._u, 0, self._subdev, freq+self._cal) + if self._tune_result: + if self._verbose: + print "Baseband frequency is", n2s(self._tune_result.baseband_freq), "Hz" + print "DXC frequency is", n2s(self._tune_result.dxc_freq), "Hz" + print "Center frequency is", n2s(freq), "Hz" + print "Residual frequency is", n2s(self._tune_result.residual_freq), "Hz" + return True + + return False + +if __name__ == '__main__': + src = usrp_source_c(verbose=True) |