HammingCodec_8_4 Class Reference

#include <HammingCodec_8_4.hh>

Inheritance diagram for HammingCodec_8_4:

Collaboration diagram for HammingCodec_8_4:

Public Member Functions
	HammingCodec_8_4 ()
virtual const uint8_t *	preamble ()
virtual uint8_t	encode4 (uint8_t nibble)
virtual uint8_t	decode4 (uint8_t symbol)
virtual uint8_t	decode8 (uint16_t symbol)

Public Attributes
const uint8_t	BITS_PER_SYMBOL
const uint16_t	START_SYMBOL
const uint8_t	PREAMBLE_MAX
const uint8_t	SYMBOL_MASK
const uint16_t	BITS_MSB

Detailed Description

Hamming(8,4) Codec for the Cosa VWI (Virtual Wire Interface). This is a linear error-correcting code that encodes 4 bits of data into 8 bits by adding 4 parity bits. Hamming's (8,4) algorithm can correct any single-bit error, or detect all single-bit and two-bit errors. This implementation uses inverted parity bits to improve DC balance in transmission (e.g. avoid coding long sequences of zero or one).

References

1. http://en.wikipedia.org/wiki/Hamming_code#.5B7.2C4.5D_Hamming_code_with_an_additional_parity_bit

Definition at line 38 of file HammingCodec_8_4.hh.

Constructor & Destructor Documentation

HammingCodec_8_4::HammingCodec_8_4 ( )

inline

Construct Hamming(8,4) codec with given bits per symbol, start symbol, and preamble size.

Definition at line 44 of file HammingCodec_8_4.hh.

Member Function Documentation

virtual uint8_t HammingCodec_8_4::decode4 ( uint8_t  symbol )

inlinevirtual

Returns 4-bit data for given symbol.

Parameters

[in]

symbol

code.

Returns

4-bit data.

Implements VWI::Codec.

Definition at line 76 of file HammingCodec_8_4.hh.

virtual uint8_t VWI::Codec::decode8 ( uint16_t  symbol )

inlinevirtualinherited

Decode two packed symbols (max 16-bit) back to 8 bits (byte) of data.

Parameters

[in]

symbol

to decode.

Returns

data.

Definition at line 136 of file VWI.hh.

virtual uint8_t HammingCodec_8_4::encode4 ( uint8_t  nibble )

inlinevirtual

Returns symbol for given 4-bit data.

Parameters

[in]

nibble

data.

Returns

8-bit symbol code.

Implements VWI::Codec.

Definition at line 65 of file HammingCodec_8_4.hh.

virtual const uint8_t* HammingCodec_8_4::preamble ( )

inlinevirtual

Returns pointer to Hamming frame preamble in program memory.

Returns

pointer.

Implements VWI::Codec.

Definition at line 54 of file HammingCodec_8_4.hh.

Member Data Documentation

const uint16_t VWI::Codec::BITS_MSB

inherited

Symbol MSB.

Definition at line 91 of file VWI.hh.

const uint8_t VWI::Codec::BITS_PER_SYMBOL

inherited

Bits per symbol.

Definition at line 76 of file VWI.hh.

const uint8_t VWI::Codec::PREAMBLE_MAX

inherited

Size of preamble with start symbol. Should be less or equal to Transmitter::PREAMBLE_MAX.

Definition at line 85 of file VWI.hh.

const uint16_t VWI::Codec::START_SYMBOL

inherited

Start symbol.

Definition at line 79 of file VWI.hh.

const uint8_t VWI::Codec::SYMBOL_MASK

inherited

Symbol mask.

Definition at line 88 of file VWI.hh.

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The documentation for this class was generated from the following files:

• libraries/HammingCodec_8_4/HammingCodec_8_4.hh
• libraries/HammingCodec_8_4/HammingCodec_8_4.cpp