ir_rmt_items.cpp File Reference

RMT item helper functions for IR protocols. More...

#include "ir_rmt_items.hpp"

Namespaces
namespace	m5
	Top level namespace of M5Stack.

Functions
void	m5::unit::ir::encodePulseDistance (item_container_type &items, uint32_t data, uint8_t bits, uint16_t bit_mark, uint16_t one_space, uint16_t zero_space, bool lsb_first=true)
	Encode a sequence of bits as pulse-distance modulated RMT items (NEC-style)
uint32_t	m5::unit::ir::decodePulseDistance (const gpio::m5_rmt_item_t *items, uint32_t num, uint32_t &data, uint8_t bits, uint16_t bit_mark, uint16_t one_space, uint16_t zero_space, uint16_t tolerance, bool lsb_first=true)
	Decode pulse-distance modulated RMT items into a data value.
void	m5::unit::ir::encodePulseWidth (item_container_type &items, uint32_t data, uint8_t bits, uint16_t one_mark, uint16_t zero_mark, uint16_t bit_space, bool lsb_first=true)
	Encode a sequence of bits as pulse-width modulated RMT items (SIRC-style)
uint32_t	m5::unit::ir::decodePulseWidth (const gpio::m5_rmt_item_t *items, uint32_t num, uint32_t &data, uint8_t bits, uint16_t one_mark, uint16_t zero_mark, uint16_t bit_space, uint16_t tolerance, bool lsb_first=true)
	Decode pulse-width modulated RMT items into a data value.
void	m5::unit::ir::encodeManchester (item_container_type &items, uint32_t data, uint8_t bits, uint16_t half_bit, bool rc5_polarity=true, bool msb_first=true)
	Encode a sequence of bits as Manchester (bi-phase) modulated RMT items (RC5-style)
uint32_t	m5::unit::ir::decodeManchester (const gpio::m5_rmt_item_t *items, uint32_t num, uint32_t &data, uint8_t bits, uint16_t half_bit, uint16_t tolerance, bool rc5_polarity=true, bool msb_first=true)
	Decode Manchester (bi-phase) modulated RMT items.

Detailed Description

RMT item helper functions for IR protocols.

Function Documentation

decodeManchester()

uint32_t m5::unit::ir::decodeManchester	(	const gpio::m5_rmt_item_t *	items,
		uint32_t	num,
		uint32_t &	data,
		uint8_t	bits,
		uint16_t	half_bit,
		uint16_t	tolerance,
		bool	rc5_polarity = true,
		bool	msb_first = true )

Decode Manchester (bi-phase) modulated RMT items.

Accepts both single-transition items (half+half in one item) and split items (consecutive half-bit items). Handles edge merging at bit boundaries.

Parameters

	items	RMT items to decode
	num	Number of items
[out]	data	Decoded data value
	bits	Expected number of bits
	half_bit	Expected half-bit duration in microseconds
	tolerance	Acceptable timing deviation in microseconds
	rc5_polarity	If true, use RC5 polarity. If false, use RC6 polarity.
	msb_first	If true, decode MSB first

Returns

Number of items consumed, or 0 on failure

decodePulseDistance()

uint32_t m5::unit::ir::decodePulseDistance	(	const gpio::m5_rmt_item_t *	items,
		uint32_t	num,
		uint32_t &	data,
		uint8_t	bits,
		uint16_t	bit_mark,
		uint16_t	one_space,
		uint16_t	zero_space,
		uint16_t	tolerance,
		bool	lsb_first = true )

Decode pulse-distance modulated RMT items into a data value.

Parameters

	items	RMT items to decode
	num	Number of items
[out]	data	Decoded data value
	bits	Expected number of bits
	bit_mark	Expected mark duration in microseconds
	one_space	Expected space duration for logic "1" in microseconds
	zero_space	Expected space duration for logic "0" in microseconds
	tolerance	Acceptable timing deviation in microseconds
	lsb_first	If true, decode as LSB first; otherwise MSB first

Returns

Number of items consumed, or 0 on failure

decodePulseWidth()

uint32_t m5::unit::ir::decodePulseWidth	(	const gpio::m5_rmt_item_t *	items,
		uint32_t	num,
		uint32_t &	data,
		uint8_t	bits,
		uint16_t	one_mark,
		uint16_t	zero_mark,
		uint16_t	bit_space,
		uint16_t	tolerance,
		bool	lsb_first = true )

Decode pulse-width modulated RMT items into a data value.

Parameters

	items	RMT items to decode
	num	Number of items
[out]	data	Decoded data value
	bits	Expected number of bits
	one_mark	Expected mark duration for logic "1" in microseconds
	zero_mark	Expected mark duration for logic "0" in microseconds
	bit_space	Expected space duration in microseconds
	tolerance	Acceptable timing deviation in microseconds
	lsb_first	If true, decode as LSB first; otherwise MSB first

Returns

Number of items consumed, or 0 on failure

encodeManchester()

void m5::unit::ir::encodeManchester	(	item_container_type &	items,
		uint32_t	data,
		uint8_t	bits,
		uint16_t	half_bit,
		bool	rc5_polarity = true,
		bool	msb_first = true )

Encode a sequence of bits as Manchester (bi-phase) modulated RMT items (RC5-style)

Each bit period = 2 half-bits. RC5 convention:

• Logic "0": Mark(half) + Space(half) (high-to-low transition at midpoint)
• Logic "1": Space(half) + Mark(half) (low-to-high transition at midpoint)

  Parameters

  [out]	items	Output container (items are appended)
  	data	Raw data value
  	bits	Number of bits to encode
  	half_bit	Half-bit duration in microseconds (889us for RC5)
  	rc5_polarity	If true, use RC5 polarity (0=mark-space, 1=space-mark). If false, use RC6 polarity (0=space-mark, 1=mark-space).
  	msb_first	If true, encode MSB first (RC5/RC6 standard)

encodePulseDistance()

void m5::unit::ir::encodePulseDistance	(	item_container_type &	items,
		uint32_t	data,
		uint8_t	bits,
		uint16_t	bit_mark,
		uint16_t	one_space,
		uint16_t	zero_space,
		bool	lsb_first = true )

Encode a sequence of bits as pulse-distance modulated RMT items (NEC-style)

Each bit is encoded as: mark(bit_mark) + space(one_space or zero_space)

Parameters

[out]	items	Output container (items are appended)
	data	Raw data value
	bits	Number of bits to encode
	bit_mark	Mark duration for each bit in microseconds
	one_space	Space duration for logic "1" in microseconds
	zero_space	Space duration for logic "0" in microseconds
	lsb_first	If true, encode LSB first; otherwise MSB first

encodePulseWidth()

void m5::unit::ir::encodePulseWidth	(	item_container_type &	items,
		uint32_t	data,
		uint8_t	bits,
		uint16_t	one_mark,
		uint16_t	zero_mark,
		uint16_t	bit_space,
		bool	lsb_first = true )

Encode a sequence of bits as pulse-width modulated RMT items (SIRC-style)

Each bit is encoded as: mark(one_mark or zero_mark) + space(bit_space)

Parameters

[out]	items	Output container (items are appended)
	data	Raw data value
	bits	Number of bits to encode
	one_mark	Mark duration for logic "1" in microseconds
	zero_mark	Mark duration for logic "0" in microseconds
	bit_space	Space duration for each bit in microseconds
	lsb_first	If true, encode LSB first; otherwise MSB first