#!/usr/bin/env python # -*- coding: utf8 -*- import bitstring """ * Preamble of at least three bytes of 0xAA. * Two synchronisation bytes: 0x2D 0xAA. * A single length byte between 0 and 64 (0x00 and 0x40). * The number of data bytes as described by the length byte, in the format described in the Layer 3 section below. * Two checksum bytes, calculated as described below. """ # Raw input (inspectrum frequency plot extracted symbols) x = [0.216841, -0.261636, 0.219096, -0.266524, 0.212065, -0.260867, 0.221935, -0.249724, 0.221802, -0.260077, 0.220824, -0.260648, 0.210396, -0.264013, 0.215528, -0.253642, 0.233618, -0.258195, 0.219111, -0.265372, 0.214256, -0.267808, 0.209937, -0.25991, 0.232465, -0.25041, -0.258406, 0.217401, -0.263702, 0.218179, 0.211704, -0.268159, 0.229335, 0.230407, -0.253414, 0.217899, -0.25817, 0.218009, -0.267789, 0.215056, -0.254367, -0.246849, -0.249974, 0.222519, -0.260761, -0.26241, -0.261301, 0.218838, -0.25504, -0.249699, -0.248335, 0.235878, 0.218087, 0.217552, -0.259925, -0.260829, 0.219753, -0.253281, 0.22945, 0.232853, 0.214607, 0.217179, -0.263678, -0.261544, -0.268515, -0.267577, 0.225176, -0.250258, 0.231237, -0.265923, 0.214075, 0.214163, -0.260433, -0.26759, -0.262872, 0.224049, 0.226019, -0.264601, -0.264295, 0.217848, 0.216708, -0.267425, -0.264499, 0.220222, -0.25903, 0.220861, 0.217432, 0.213846, -0.266552, -0.265628, -0.26728, 0.218866, 0.223372, -0.252216, -0.257527, 0.218207, -0.26554, -0.266194, -0.263852, 0.214561, 0.222652, -0.255715, -0.258746, 0.216042, 0.214921, -0.262316, -0.265843, 0.213283, -0.262132, 0.234911, 0.222425, -0.258964, -0.268212, -0.261948, -0.261823, 0.211988, 0.218162, -0.262929, -0.248741, 0.225102, 0.219269, -0.266022, -0.265968, 0.217225, -0.267007, 0.217196, 0.235238, 0.227095, -0.25925, -0.266509, -0.262533, 0.215291, 0.216175, -0.270646, 0.227622, 0.232801, -0.249791, -0.247158, -0.266351, 0.21378, 0.218169, 0.214519, -0.25927, -0.251352, 0.232727, -0.251546, -0.272696, 0.210396, -0.264262, 0.212666, 0.22186, -0.260639, -0.257088, -0.253097, -0.259826, 0.215589, 0.216688, -0.265696, -0.269624, 0.220937, 0.217404, -0.255146, -0.249656, 0.220375, -0.267294, 0.218417, 0.213958, 0.215574, -0.264102, -0.262655, -0.253592, 0.219836, 0.220085, 0.221188, -0.261837, -0.260646, 0.214605, -0.264604, -0.267797, 0.229365, 0.237114, -0.260418, -0.266878, -0.263119, 0.21506, -0.263434, 0.213958, -0.250937, 0.227602, -0.24999, 0.223627, -0.264232, -0.259437, -0.255263, -0.264628, 0.225421, 0.231303, -0.24944, -0.249487, 0.21535, -0.26258, -0.262921, -0.259475, 0.223044, 0.227399, -0.24976, -0.246236, 0.218301, -0.260648, -0.26285, -0.261321, 0.217338, -0.256522, 0.226121, 0.234016, 0.231818, -0.262323, -0.264795, -0.266239, 0.221945, 0.217747, -0.260885, 0.224342, 0.228173, 0.217476, -0.264719, 0.219541, -0.262284, 0.212248, 0.21203, -0.264602, 0.225842, -0.261688, -0.26651, -0.262665, 0.223527, 0.221421, -0.262174, -0.263653, -0.260515, -0.25002, -0.254465, 0.219979, -0.26266, 0.216723, -0.262255, -0.264995, 0.217492, -0.245421, -0.249774, -0.252032, 0.221862, -0.257836, 0.220338, 0.220344, -0.26288, 0.232661, -0.250644, -0.246684, 0.224459, 0.215851, -0.258179, -0.259633, 0.218951, 0.218075, -0.245128, -0.253764, 0.228257, 0.22736, -0.266995, -0.26488, 0.216476, 0.216074, -0.261651, 0.222593, -0.253993, 0.23501, 0.218582, -0.260957, 0.217979, 0.219902, -0.263794, 0.223031, -0.255528, -0.245308, 0.221199, 0.219862, 0.219594, 0.221592, -0.266644, 0.22015, -0.261503, 0.222219, -0.249429, -0.253903, 0.220405, 0.218208, -0.258208, 0.213865, 0.215591, 0.218854, -0.243035, -0.24893, 0.225554, -0.256934, -0.260774, -0.255451, 0.216236, 0.211297, -0.248017, -0.24797, -0.248842, 0.227713, -0.25972, 0.219987, -0.263378, 0.217475, 0.217265, 0.227285, -0.249343, 0.234129, 0.235813, 0.21725, -0.26081, 0.218495, 0.219381, 0.218673, 0.225591, -0.250235, 0.227448, 0.222044, -0.2629, -0.269487, -0.266359, -0.260572, 0.216512, -0.337241, -0.260326, -0.265867, -0.265165] # Binary threshold more or less than 0 y = [1 if n>0 else 0 for n in x] # Create BitArray of our data z = bitstring.BitArray(bin=''.join([str(n) for n in y])) # Pad bitstream for 8-bit bytes while len(z) % 8: z.prepend('0b0') # Discard preamble z <<= z.find('0x2daa')[0] # Discard sync bits z <<= 16 # Get packet length l = ord(z.bytes[0]) z <<= 8 # Get packet content data = z.bytes[:l] z <<= 8*l # Get checksum cs = z.bytes[:2] packet = { 'length': l, 'data': data, 'checksum': cs } print(packet)