Added ability to supply device arguments as parameter to applications.

Change adressing #140 enhancement request.
It is possible to select rtl-sdr dongle:
-with device index through commanline parameter: `--args="rtl=1"` (where 1 is the device index). Caution: device index is not unique identifier and it changes on each connection of the dongle.
-with devices serial number, the commandline option in this case has following form: `--args="rtl=00000001"` (where 00000001 is the serial number).

NOTE: You can set the serial number with use of:
```sh
rtl_eeprom -s <serial_number>
```

1 files changed, 6 insertions, 3 deletions

diff --git a/apps/grgsm_livemon b/apps/grgsm_livemon
index 9c5e8a9..7bf4ee3 100755
--- a/apps/grgsm_livemon
+++ b/apps/grgsm_livemon
@@ -35,7 +35,7 @@ import time
 
 class grgsm_livemon(gr.top_block, Qt.QWidget):
 
-    def __init__(self, fc=939.4e6, gain=30, ppm=0, samp_rate=2000000.052982, shiftoff=400e3):
+    def __init__(self, fc=939.4e6, gain=30, ppm=0, samp_rate=2000000.052982, shiftoff=400e3, args=""):
         gr.top_block.__init__(self, "Gr-gsm Livemon")
         Qt.QWidget.__init__(self)
         self.setWindowTitle("Gr-gsm Livemon")
@@ -86,7 +86,7 @@ class grgsm_livemon(gr.top_block, Qt.QWidget):
         self._fc_slider_range = Range(925e6, 1990e6, 2e5, fc, 100)
         self._fc_slider_win = RangeWidget(self._fc_slider_range, self.set_fc_slider, "Frequency", "counter_slider", float)
         self.top_layout.addWidget(self._fc_slider_win)
-        self.rtlsdr_source_0 = osmosdr.source( args="numchan=" + str(1) + " " + "" )
+        self.rtlsdr_source_0 = osmosdr.source( args="numchan=" + str(1) + " " + args )
         self.rtlsdr_source_0.set_sample_rate(samp_rate)
         self.rtlsdr_source_0.set_center_freq(fc_slider-shiftoff, 0)
         self.rtlsdr_source_0.set_freq_corr(ppm_slider, 0)
@@ -260,13 +260,16 @@ if __name__ == '__main__':
         help="Set samp_rate [default=%default]")
     parser.add_option("-o", "--shiftoff", dest="shiftoff", type="eng_float", default=eng_notation.num_to_str(400e3),
         help="Set shiftoff [default=%default]")
+    parser.add_option("", "--args", dest="args", type="string", default="",
+        help="Set device arguments [default=%default]")
+                
     (options, args) = parser.parse_args()
 #    from distutils.version import StrictVersion
 #    if StrictVersion(Qt.qVersion()) >= StrictVersion("4.5.0"):
 #        Qt.QApplication.setGraphicsSystem(gr.prefs().get_string('qtgui','style','raster'))
     Qt.QApplication.setGraphicsSystem(gr.prefs().get_string('qtgui','style','raster'))
     qapp = Qt.QApplication(sys.argv)
-    tb = grgsm_livemon(fc=options.fc, gain=options.gain, ppm=options.ppm, samp_rate=options.samp_rate, shiftoff=options.shiftoff)
+    tb = grgsm_livemon(fc=options.fc, gain=options.gain, ppm=options.ppm, samp_rate=options.samp_rate, shiftoff=options.shiftoff, args=options.args)
     tb.start()
     tb.show()