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#
# Copyright 2005, 2006, 2007 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# GNU Radio is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# GNU Radio is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU Radio; see the file COPYING. If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
#
from math import pi
from gnuradio import gr
import gnuradio.gr.gr_threading as _threading
import packet_utils
import digital_swig
# /////////////////////////////////////////////////////////////////////////////
# mod/demod with packets as i/o
# /////////////////////////////////////////////////////////////////////////////
class mod_pkts(gr.hier_block2):
"""
Wrap an arbitrary digital modulator in our packet handling framework.
Send packets by calling send_pkt
"""
def __init__(self, modulator, access_code=None, msgq_limit=2, pad_for_usrp=True,
use_whitener_offset=False, modulate=True):
"""
Hierarchical block for sending packets
Packets to be sent are enqueued by calling send_pkt.
The output is the complex modulated signal at baseband.
@param modulator: instance of modulator class (gr_block or hier_block2)
@type modulator: complex baseband out
@param access_code: AKA sync vector
@type access_code: string of 1's and 0's between 1 and 64 long
@param msgq_limit: maximum number of messages in message queue
@type msgq_limit: int
@param pad_for_usrp: If true, packets are padded such that they end up a multiple of 128 samples
@param use_whitener_offset: If true, start of whitener XOR string is incremented each packet
See gmsk_mod for remaining parameters
"""
gr.hier_block2.__init__(self, "mod_pkts",
gr.io_signature(0, 0, 0), # Input signature
gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
self._modulator = modulator
self._pad_for_usrp = pad_for_usrp
self._use_whitener_offset = use_whitener_offset
self._whitener_offset = 0
if access_code is None:
access_code = packet_utils.default_access_code
if not packet_utils.is_1_0_string(access_code):
raise ValueError, "Invalid access_code %r. Must be string of 1's and 0's" % (access_code,)
self._access_code = access_code
# accepts messages from the outside world
self._pkt_input = gr.message_source(gr.sizeof_char, msgq_limit)
self.connect(self._pkt_input, self._modulator, self)
def send_pkt(self, payload='', eof=False):
"""
Send the payload.
@param payload: data to send
@type payload: string
"""
if eof:
msg = gr.message(1) # tell self._pkt_input we're not sending any more packets
else:
# print "original_payload =", string_to_hex_list(payload)
pkt = packet_utils.make_packet(payload,
self._modulator.samples_per_symbol(),
self._modulator.bits_per_symbol(),
self._access_code,
self._pad_for_usrp,
self._whitener_offset)
#print "pkt =", string_to_hex_list(pkt)
msg = gr.message_from_string(pkt)
if self._use_whitener_offset is True:
self._whitener_offset = (self._whitener_offset + 1) % 16
self._pkt_input.msgq().insert_tail(msg)
class demod_pkts(gr.hier_block2):
"""
Wrap an arbitrary digital demodulator in our packet handling framework.
The input is complex baseband. When packets are demodulated, they are passed to the
app via the callback.
"""
def __init__(self, demodulator, access_code=None, callback=None, threshold=-1):
"""
Hierarchical block for demodulating and deframing packets.
The input is the complex modulated signal at baseband.
Demodulated packets are sent to the handler.
@param demodulator: instance of demodulator class (gr_block or hier_block2)
@type demodulator: complex baseband in
@param access_code: AKA sync vector
@type access_code: string of 1's and 0's
@param callback: function of two args: ok, payload
@type callback: ok: bool; payload: string
@param threshold: detect access_code with up to threshold bits wrong (-1 -> use default)
@type threshold: int
"""
gr.hier_block2.__init__(self, "demod_pkts",
gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
gr.io_signature(0, 0, 0)) # Output signature
self._demodulator = demodulator
if access_code is None:
access_code = packet_utils.default_access_code
if not packet_utils.is_1_0_string(access_code):
raise ValueError, "Invalid access_code %r. Must be string of 1's and 0's" % (access_code,)
self._access_code = access_code
if threshold == -1:
threshold = 12 # FIXME raise exception
self._rcvd_pktq = gr.msg_queue() # holds packets from the PHY
self.correlator = digital_swig.correlate_access_code_bb(access_code, threshold)
self.framer_sink = gr.framer_sink_1(self._rcvd_pktq)
self.connect(self, self._demodulator, self.correlator, self.framer_sink)
self._watcher = _queue_watcher_thread(self._rcvd_pktq, callback)
class _queue_watcher_thread(_threading.Thread):
def __init__(self, rcvd_pktq, callback):
_threading.Thread.__init__(self)
self.setDaemon(1)
self.rcvd_pktq = rcvd_pktq
self.callback = callback
self.keep_running = True
self.start()
def run(self):
while self.keep_running:
msg = self.rcvd_pktq.delete_head()
ok, payload = packet_utils.unmake_packet(msg.to_string(), int(msg.arg1()))
if self.callback:
self.callback(ok, payload)
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