from gnuradio import gr, gru, usrp
import usrp_dbid
from gnuradio import audio
from gnuradio import blks
import os
import time
import struct


fg=gr.flow_graph()

### Create the USRP ###
u = usrp.source_c(decim_rate=32)         # decimation is even values in range [4, 256].
                                        # 4 can only be used with 4 bit sampling
width = 8
shift = 8
format = u.make_format(width, shift)
#r = u.set_format(format)               # Uncomment to enable 8-bit sampling
#print "set_format =", r                # Uncomment to enable 8-bit sampling

usrp_rate = u.adc_freq() / u.decim_rate()


### 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)


### Change the baseband lowpass filter on daughterboard to reduce bandwidth.
### Can be set anywhere from 4 to 33MHz ###
#subdev.set_bw(1e6)


#### set initial values

# Set gain to max
# Gain is 0 to 104, in steps of 1
g_range = subdev.gain_range()
subdev.set_gain(0)


# 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


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

#Multiplier
multiplier = gr.multiply_ff ()
multiplier1 = gr.multiply_ff ()

#Adder
adder = gr.add_ff()


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

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

fg.connect((c2f,0),(multiplier,0))
fg.connect((c2f,0),(multiplier,1))

fg.connect((c2f,1),(multiplier1,0))
fg.connect((c2f,1),(multiplier1,1))

fg.connect(multiplier,(adder,0))
fg.connect(multiplier1,(adder,1))

fg.connect(adder, sink)

fg.start()


#Set number of samples
num_samples = 1000
repeat = 20                 #repeat 20 times

#Run graph until correct number of samples written to file
while os.path.getsize("temp_power.dat") < num_samples * (repeat+1) * gr.sizeof_float:
        time.sleep(0.0001)

#Stop the graph
fg.stop()

#Read in num_samples at a time, and display the average
fin = open("temp_power.dat", 'rb')
total_sum = 0

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


for i in range(repeat):
    
    # Read in first set of samples to a list
    data = struct.unpack(str(num_samples) + 'f' ,fin.read(num_samples * gr.sizeof_float))
    
    #Now average out the data and print the result
    sum = 0
    for val in data: sum += val
    print sum / num_samples * 1.0
    
    total_sum += sum / num_samples * 1.0
    
#Now print average of all samples
print "Overall Average: " , total_sum/repeat * 1.0