#!/usr/bin/env python

from gnuradio import gr, gru, eng_notation
from gnuradio import usrp
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import usrp_dbid
import time
import os.path
import struct

fg=gr.flow_graph()

### Create the USRP ###
u = usrp.source_c(0, decim_rate=256)

### determine the daughterboard subdevice we're using ###
rx_subdev_spec = usrp.pick_subdev(u, (usrp_dbid.TV_RX,))
u.set_mux(usrp.determine_rx_mux_value(u, rx_subdev_spec))
subdev = usrp.selected_subdev(u, rx_subdev_spec)


#### set initial values

# Set gain
# Gain is 0 to 115, in steps of 1
g_range = subdev.gain_range()
subdev.set_gain(50)


# Set frequency to mid-point
# Frequency is 500MHz to 2.6GHZ, in steps of 1MHz
f_range = subdev.freq_range()
freq = 100e6                        # frequency to tune to
r = u.tune(0, subdev, freq)         # 0 is DDC channel


#Vector sink
#sink = gr.file_sink(gr.sizeof_float, "signal_samples.dat")


#Set number of samples
nsamples = 2000

#Complex to Float Conversion
c2f=gr.complex_to_float()

head = gr.head(gr.sizeof_float, int(nsamples))


#Wiring it all together
fg.connect(u, c2f, head, sink)


fg.start()

#Read in num_samples at a time, and display the average
#fin = open("signal_samples.dat", 'rb')

#Dump the first set of samples as they will be erroneous (bug in USRP)
#fin.read(2 * nsamples * gr.sizeof_short)

#fin.close()

#Stop the graph
fg.stop()