#!/usr/bin/env python

"""
Read samples from the USRP and write to file formatted as binary
single-precision complex values.

"""

from gnuradio import gr, eng_notation
from gnuradio import usrp
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import sys

class my_graph(gr.flow_graph):

    def __init__(self):
        gr.flow_graph.__init__(self)

        usage="%prog: [options] output_filename"
        parser = OptionParser(option_class=eng_option, usage=usage)
        parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=(0, 0),
                          help="select USRP Rx side A or B (default=A)")
        parser.add_option("-u", "--usrp", type="int", default=0,
                          help="set the usrp board to receive signal [default=%default]")
        parser.add_option("-d", "--decim", type="int", default=16,
                          help="set fgpa decimation rate to DECIM [default=%default]")
        parser.add_option("-f", "--freq", type="eng_float", default=None,
                          help="set frequency to FREQ", metavar="FREQ")
        parser.add_option("-g", "--gain", type="eng_float", default=None,
                          help="set gain in dB (default is midpoint)")
        parser.add_option("-N", "--nsamples", type="eng_float", default=None,
                          help="number of samples to collect [default=+inf]")
        (options, args) = parser.parse_args ()
        if len(args) != 1:
            parser.print_help()
            raise SystemExit, 1
        filename = args[0]

        if options.freq is None:
            parser.print_help()
            sys.stderr.write('You must specify the frequency with -f FREQ\n');
            raise SystemExit, 1

        # build the graph
        self.u = usrp.source_c(which=options.usrp,decim_rate=options.decim)
        self.dst = gr.file_sink(gr.sizeof_gr_complex, filename)
        if options.nsamples is None:
            self.connect(self.u, self.dst)
        else:
            self.head = gr.head(gr.sizeof_gr_complex, int(options.nsamples))
            self.connect(self.u, self.head, self.dst)

        if options.rx_subdev_spec is None:
            options.rx_subdev_spec = usrp.pick_rx_subdevice(self.u)
	m = usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec)
	print "mux = %#04x" % (m,)
        self.u.set_mux(usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec))
        #self.u.set_mux(0xf0)
	#self.u.set_pga(options.usrp,10)

        # determine the daughterboard subdevice we're using
        self.subdev = usrp.selected_subdev(self.u, options.rx_subdev_spec)
	print "subdev", options.rx_subdev_spec
        print "Using RX d'board %s" % (self.subdev.side_and_name(),)
        input_rate = self.u.adc_freq() / self.u.decim_rate()
        print "USB sample rate %s" % (eng_notation.num_to_str(input_rate))

        if options.gain is None:
            # if no gain was specified, use the mid-point in dB
            g = self.subdev.gain_range()
	    print g[0],"   ",g[1], "   ",g[2],"   ",float(g[0]+g[1])/2
            options.gain = float(g[0]+g[1])/2
        self.subdev.set_gain(options.gain)
	print "gain is:",options.gain

        r = self.u.tune(0, self.subdev, options.freq)
        if not r:
            sys.stderr.write('Failed to set frequency\n')
            raise SystemExit, 1

        
if __name__ == '__main__':
    try:
        my_graph().run()
    except KeyboardInterrupt:
        pass