#!/usr/bin/env python

#
# Decoder of IEEE 802.15.4 RADIO Packets.
#
# Modified by: Thomas Schmid, Leslie Choong, Mikhail Tadjikov
#
  
from gnuradio import gr, eng_notation
from gnuradio import uhd
from gnuradio.ucla_blks import ieee802_15_4_pkt
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import struct, sys, time

n2s = eng_notation.num_to_str

class stats(object):
    def __init__(self):
        self.npkts = 0
        self.nright = 0
        
    
class oqpsk_rx_graph (gr.top_block):
    def __init__(self, options, rx_callback):
        gr.top_block.__init__(self)
        # ----------------------------------------------------------------
        self.data_rate = options.data_rate
        self.samples_per_symbol = 2
        self._samp_rate = 200000
        print "data_rate = ", n2s(self.data_rate)
        print "samples_per_symbol = ", self.samples_per_symbol

        self.u = uhd.usrp_source (device_addr=options.address,
                                  io_type=uhd.io_type.COMPLEX_FLOAT32,
                                  num_channels=1)
        # set the antenna
        self.u.set_antenna(options.antenna, 0)
        # set sampling rate
        self.u.set_samp_rate(self._samp_rate)
        # set and print center frequency
        treq = uhd.tune_request(options.center_freq)
        self.u.set_center_freq(treq)
        cntr_freq = self.u.get_center_freq()
        print "Center freqency: %d " % (cntr_freq)

        self.packet_receiver = ieee802_15_4_pkt.ieee802_15_4_demod_pkts(self,
                                                                callback=rx_callback,
                                                                sps=self.samples_per_symbol,
                                                                symbol_rate=self.data_rate,
                                                                threshold=-1)
        self.connect(self.u, self.packet_receiver)
        # self.vecsink = gr.vector_sink_c()
        # self.connect(self.u, self.vecsink)

def main ():

    def rx_callback(ok, payload):
        st.npkts += 1
        if ok:
            st.nright += 1

        (pktno,) = struct.unpack('!H', payload[0:2])
        print "ok = %5r  pktno = %4d  len(payload) = %4d  %d/%d" % (ok, pktno, len(payload),
                                                                    st.nright, st.npkts)
        print " ------------------------"
        sys.stdout.flush()

    parser = OptionParser(option_class=eng_option)
    parser.add_option("-a", "--address", type="string", default="addr=192.168.10.2",
                      help="Address of UHD device, [default=%default]")
    parser.add_option("-A", "--antenna", type="string", default="RX2",
                      help="select Rx Antenna where appropiate")
    parser.add_option("-c", "--center_freq", type="eng_float", default=2475000000,
                      help="set Rx center frequency to FREQ", metavar="FREQ")
    parser.add_option("-r", "--data_rate", type="eng_float", default=2000000)
    parser.add_option("-f", "--filename", type="string", default="rx.dat",
                      help="write data to FILENAME")
    parser.add_option("-g", "--gain", type="eng_float", default=0,
                      help="set Rx PGA gain in dB [0,20]")
    (options, args) = parser.parse_args()

    st = stats()

    tb = oqpsk_rx_graph(options, rx_callback)
    tb.start()

    tb.wait()

if __name__ == '__main__':
    # insert this in your test code...
    #import os
    #print 'Blocked waiting for GDB attach (pid = %d)' % (os.getpid(),)
    #raw_input ('Press Enter to continue: ')
    
    main ()