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46 lines
1.4 KiB
46 lines
1.4 KiB
class Encoder:
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"""
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Hamming and Manchester Encoding example
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Author: Joel Addison
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Date: March 2013
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Functions to do (7,4) hamming encoding and decoding, including error detection
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and correction.
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Manchester encoding and decoding is also included, and by default will use
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least bit ordering for the byte that is to be included in the array.
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"""
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###############################################################
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# Further work on fork
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# Copyright (C) 2017 David Robinson
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def extract_bit(self, byte, pos):
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"""
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Extract a bit from a given byte using MS ordering.
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ie. B7 B6 B5 B4 B3 B2 B1 B0
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"""
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return (byte >> pos) & 0x01
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def manchester_encode(self, byte):
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"""
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Encode a byte using Manchester encoding. Returns an array of bits.
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Adds two start bits (1, 1) and one stop bit (0) to the array.
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"""
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# Add start bits (encoded 1, 1)
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# manchester_encoded = [0, 1, 0, 1]
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manchester_encoded = []
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# Encode byte
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for i in range(7, -1, -1):
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if self.extract_bit(byte, i):
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manchester_encoded.append(0)
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manchester_encoded.append(1)
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else:
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manchester_encoded.append(1)
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manchester_encoded.append(0)
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# Add stop bit (encoded 0)
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# manchester_encoded.append(1)
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# manchester_encoded.append(0)
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return manchester_encoded
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