def __init__(self, samples_per_symbol, bits_per_symbol, access_code='', pad_for_usrp=True):
"""
packet_mod constructor.
Args:
samples_per_symbol: number of samples per symbol
bits_per_symbol: number of bits per symbol
access_code: AKA sync vector
pad_for_usrp: If true, packets are padded such that they end up a multiple of 128 samples
payload_length: number of bytes in a data-stream slice
"""
#setup parameters
self._samples_per_symbol = samples_per_symbol
self._bits_per_symbol = bits_per_symbol
self._pad_for_usrp = pad_for_usrp
if not access_code: #get access code
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
self._pad_for_usrp = pad_for_usrp
#create blocks
msg_source = blocks.message_source(gr.sizeof_char, DEFAULT_MSGQ_LIMIT)
self._msgq_out = msg_source.msgq()
#initialize hier2
gr.hier_block2.__init__(
self,
"packet_encoder",
gr.io_signature(0, 0, 0), # Input signature
gr.io_signature(1, 1, gr.sizeof_char) # Output signature
)
#connect
self.connect(msg_source, self)
def __init__(self, access_code='', threshold=-1, callback=None):
"""
packet_demod constructor.
Args:
access_code: AKA sync vector
threshold: detect access_code with up to threshold bits wrong (0 -> use default)
callback: a function of args: ok, payload
"""
#access code
if not access_code: #get access code
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
#threshold
if threshold < 0: threshold = DEFAULT_THRESHOLD
self._threshold = threshold
#blocks
msgq = gr.msg_queue(DEFAULT_MSGQ_LIMIT) #holds packets from the PHY
correlator = digital.correlate_access_code_bb(self._access_code, self._threshold)
framer_sink = digital.framer_sink_1(msgq)
#initialize hier2
gr.hier_block2.__init__(
self,
"packet_decoder",
gr.io_signature(1, 1, gr.sizeof_char), # Input signature
gr.io_signature(0, 0, 0) # Output signature
)
#connect
self.connect(self, correlator, framer_sink)
#start thread
_packet_decoder_thread(msgq, callback)