m5::unit::ir::SircCodec Class Reference

Sony SIRC IR protocol encoder/decoder. More...

#include <sirc_codec.hpp>

Inheritance diagram for m5::unit::ir::SircCodec:

Public Types
enum class	Variant : uint8_t { SIRC12 = 12 , SIRC15 = 15 , SIRC20 = 20 }
	SIRC protocol variants.

Public Member Functions
	SircCodec (Variant v=Variant::SIRC12)
	Constructor.
item_container_type	encode (uint16_t address, uint16_t command, bool repeat) override
	Encode a Sony SIRC frame for the currently selected variant.
bool	decode (const gpio::m5_rmt_item_t *items, uint32_t num, DecodeResult &result) override
	Decode a Sony SIRC frame and, on success, sync the active variant.
uint32_t	carrierFrequencyHz () const override
	Carrier frequency for Sony SIRC (40 kHz)
uint8_t	minFrames () const override
	Sony SIRC requires the frame to be sent at least 3 times per keypress.
uint16_t	frameGapUs () const override
	Inter-frame gap ≈ 30 ms (keeps the 45 ms start-to-start cycle)
Variant	variant () const
	Get current variant.
void	setVariant (Variant v)
	Set variant (12 / 15 / 20-bit)
Public Member Functions inherited from m5::unit::ir::IRCodec
	IRCodec (CodecType t)
CodecType	type () const
	Get codec type for safe downcasting.
virtual float	carrierDuty () const
	Carrier duty cycle (0.0 - 1.0)
virtual bool	decode (const m5::unit::gpio::m5_rmt_item_t *items, uint32_t num, DecodeResult &result)=0
	Try to decode RMT items into an IR command.

Detailed Description

Sony SIRC IR protocol encoder/decoder.

• Carrier: 40 kHz, duty 1/3
• Modulation: Pulse Width (space constant, mark varies)
• Bit order: LSB first
• 12-bit: 7-bit command + 5-bit address
• 15-bit: 7-bit command + 8-bit address
• 20-bit: 7-bit command + 5-bit address + 8-bit extended

Timing

Element	Mark (us)	Space (us)
Start	2400	600
Bit "1"	1200	600
Bit "0"	600	600

Constructor & Destructor Documentation

SircCodec()

m5::unit::ir::SircCodec::SircCodec ( Variant v = Variant::SIRC12 )

inlineexplicit

Constructor.

Parameters

v	Initial SIRC variant (default SIRC12)

Member Function Documentation

carrierFrequencyHz()

uint32_t m5::unit::ir::SircCodec::carrierFrequencyHz ( ) const

inlineoverridevirtual

Carrier frequency for Sony SIRC (40 kHz)

Implements m5::unit::ir::IRCodec.

encode()

item_container_type m5::unit::ir::SircCodec::encode ( uint16_t address, uint16_t command, bool repeat )

overridevirtual

Encode a Sony SIRC frame for the currently selected variant.

Implements m5::unit::ir::IRCodec.

frameGapUs()

uint16_t m5::unit::ir::SircCodec::frameGapUs ( ) const

inlineoverridevirtual

Inter-frame gap ≈ 30 ms (keeps the 45 ms start-to-start cycle)

Reimplemented from m5::unit::ir::IRCodec.

minFrames()

uint8_t m5::unit::ir::SircCodec::minFrames ( ) const

inlineoverridevirtual

Sony SIRC requires the frame to be sent at least 3 times per keypress.

Reimplemented from m5::unit::ir::IRCodec.

setVariant()

void m5::unit::ir::SircCodec::setVariant ( Variant v )

inline

Set variant (12 / 15 / 20-bit)

Parameters

v	New variant to apply on subsequent encode() calls

variant()

Variant m5::unit::ir::SircCodec::variant ( ) const

inline

Get current variant.

Returns

Variant currently used for encode()