High-performance ESP32 IR RX driver using the RMT peripheral and Manchester decoding. More...

#include <RxDriverESP32.h>

Inheritance diagram for pulsewire::RxDriverESP32:

Collaboration diagram for pulsewire::RxDriverESP32:

[legend]

Public Member Functions
	RxDriverESP32 (ManchesterCodec &codec, uint8_t pin, uint32_t freqHz=DEFAULT_BIT_FREQ_HZ, bool useChecksum=false, uint32_t timeoutUs=5000)

void	setFrameSize (uint8_t size) override

void	setRxBufferSize (size_t size) override
	Set the size of the internal RX buffer.

bool	begin (uint8_t frameSize) override

bool	begin () override

void	end () override
	Stop the receiver.

size_t	readBytes (uint8_t *buffer, size_t length) override

int	available () override
	Get the number of bytes available in the internal buffer.

virtual void	setFrameSize (uint16_t size)=0
	Set the expected frame size for dynamic data reception.

virtual bool	begin (uint16_t bitFrequencyHz)=0
	Start the receiver.

Static Protected Member Functions
static void	rxTask (void *arg)
	FreeRTOS task for receiving and decoding IR frames using ESP32 RMT.

Protected Attributes
size_t	_rxBufferSize = 256

uint8_t	_rxPin

uint16_t	_frameSize = DEFAULT_FRAME_SIZE

uint32_t	_freqHz

rmt_channel_handle_t	_rxChannel = nullptr

TaskHandle_t	_taskHandle = nullptr

volatile bool	_stopTask = false

uint16_t	_preambleBits = 0

bool	_inFrame = false

QueueHandle_t	_frameQueue = nullptr

RingBuffer< uint8_t >	rxOverflow

ManchesterCodec &	_codec

Vector< uint8_t >	manchesterBits

bool	_useChecksum = false

uint32_t	_timeoutUs = 5000

uint32_t	_lastSymbolTime = 0

Detailed Description

High-performance ESP32 IR RX driver using the RMT peripheral and Manchester decoding.

Uses the ESP32 RMT peripheral for efficient IR edge capture and decoding.
Supports concurrent IR receive and transmit by using separate RMT channels for RX and TX.
RX and TX channels are independent; no conflicts as long as each driver manages its own channel.
Frame size and buffer size are configurable.
Asynchronous reception is handled by a FreeRTOS task.
Bit frequency (Hz) should match the transmitter for reliable decoding.
- Typical values: 300–2400 Hz for consumer IR remotes, 1000–2000 Hz for Arduino/ESP32 projects.
- ESP32 RMT can handle higher frequencies, but receiver hardware and software must be tuned accordingly.
For Manchester encoding, bit frequency = baud rate (bits per second).

Note: Supports sending and receiving on the same microcontroller without conflicts.

Definition at line 43 of file RxDriverESP32.h.

Constructor & Destructor Documentation

◆ RxDriverESP32()

pulsewire::RxDriverESP32::RxDriverESP32	(	ManchesterCodec &	codec,
		uint8_t	pin,
		uint32_t	freqHz = `DEFAULT_BIT_FREQ_HZ`,
		bool	useChecksum = `false`,
		uint32_t	timeoutUs = `5000`
	)

inline

Parameters

codec	IR codec
pin	RX pin
freqHz	Bit frequency
useChecksum	If true, validate checksum (default: false)
timeoutUs	Timeout in microseconds to flush frame if no symbol received (default: 5000)

Definition at line 52 of file RxDriverESP32.h.

Member Function Documentation

◆ available()

int pulsewire::RxDriverESP32::available ( )

inlineoverridevirtual

Get the number of bytes available in the internal buffer.

Implements pulsewire::RxDriver.

Definition at line 159 of file RxDriverESP32.h.

◆ begin() [1/3]

bool pulsewire::RxDriverESP32::begin ( )

inlineoverride

Definition at line 67 of file RxDriverESP32.h.

◆ begin() [2/3]

virtual bool pulsewire::RxDriver::begin ( uint16_t bitFrequencyHz )

pure virtualinherited

Start the receiver.

Implemented in pulsewire::RxDriverArduino.

◆ begin() [3/3]

bool pulsewire::RxDriverESP32::begin ( uint8_t frameSize )

inlineoverride

Definition at line 62 of file RxDriverESP32.h.

◆ end()

void pulsewire::RxDriverESP32::end ( )

inlineoverridevirtual

Stop the receiver.

Implements pulsewire::RxDriver.

Definition at line 115 of file RxDriverESP32.h.

◆ readBytes()

size_t pulsewire::RxDriverESP32::readBytes	(	uint8_t *	data,
		size_t	size
	)

inlineoverridevirtual

Read up to 'size' bytes from the internal buffer into 'data'. Returns number of bytes read.

Implements pulsewire::RxDriver.

Definition at line 130 of file RxDriverESP32.h.

◆ rxTask()

static void pulsewire::RxDriverESP32::rxTask ( void * arg )

inlinestaticprotected

FreeRTOS task for receiving and decoding IR frames using ESP32 RMT.

This method is protocol-agnostic: it processes each RMT symbol by summing durations and inferring the logic level, then passes these to the codec's decodeEdge method. As long as the codec implements decodeEdge for its protocol, this works for Manchester, PulseWidth, PulseDistance, etc.

Parameters

arg	Pointer to RxDriverESP32 instance.

Definition at line 192 of file RxDriverESP32.h.

◆ setFrameSize() [1/2]

virtual void pulsewire::RxDriver::setFrameSize ( uint16_t size )

pure virtualinherited

Set the expected frame size for dynamic data reception.

Implemented in pulsewire::RxDriverArduino.

◆ setFrameSize() [2/2]

void pulsewire::RxDriverESP32::setFrameSize ( uint8_t size )

inlineoverride

Definition at line 58 of file RxDriverESP32.h.

◆ setRxBufferSize()

void pulsewire::RxDriverESP32::setRxBufferSize ( size_t size )

inlineoverridevirtual

Set the size of the internal RX buffer.

Implements pulsewire::RxDriver.

Definition at line 60 of file RxDriverESP32.h.

Field Documentation

◆ _codec

ManchesterCodec& pulsewire::RxDriverESP32::_codec

protected

Definition at line 176 of file RxDriverESP32.h.

◆ _frameQueue

QueueHandle_t pulsewire::RxDriverESP32::_frameQueue = nullptr

protected

Definition at line 174 of file RxDriverESP32.h.

◆ _frameSize

uint16_t pulsewire::RxDriverESP32::_frameSize = DEFAULT_FRAME_SIZE

protected

Definition at line 167 of file RxDriverESP32.h.

◆ _freqHz

uint32_t pulsewire::RxDriverESP32::_freqHz

protected

Definition at line 168 of file RxDriverESP32.h.

◆ _inFrame

bool pulsewire::RxDriverESP32::_inFrame = false

protected

Definition at line 173 of file RxDriverESP32.h.

◆ _lastSymbolTime

uint32_t pulsewire::RxDriverESP32::_lastSymbolTime = 0

protected

Definition at line 180 of file RxDriverESP32.h.

◆ _preambleBits

uint16_t pulsewire::RxDriverESP32::_preambleBits = 0

protected

Definition at line 172 of file RxDriverESP32.h.

◆ _rxBufferSize

size_t pulsewire::RxDriverESP32::_rxBufferSize = 256

protected

Definition at line 165 of file RxDriverESP32.h.

◆ _rxChannel

rmt_channel_handle_t pulsewire::RxDriverESP32::_rxChannel = nullptr

protected

Definition at line 169 of file RxDriverESP32.h.

◆ _rxPin

uint8_t pulsewire::RxDriverESP32::_rxPin

protected

Definition at line 166 of file RxDriverESP32.h.

◆ _stopTask

volatile bool pulsewire::RxDriverESP32::_stopTask = false

protected

Definition at line 171 of file RxDriverESP32.h.

◆ _taskHandle

TaskHandle_t pulsewire::RxDriverESP32::_taskHandle = nullptr

protected

Definition at line 170 of file RxDriverESP32.h.

◆ _timeoutUs

uint32_t pulsewire::RxDriverESP32::_timeoutUs = 5000

protected

Definition at line 179 of file RxDriverESP32.h.

◆ _useChecksum

bool pulsewire::RxDriverESP32::_useChecksum = false

protected

Definition at line 178 of file RxDriverESP32.h.

◆ manchesterBits

Vector<uint8_t> pulsewire::RxDriverESP32::manchesterBits

protected

Definition at line 177 of file RxDriverESP32.h.

◆ rxOverflow

RingBuffer<uint8_t> pulsewire::RxDriverESP32::rxOverflow

protected

Definition at line 175 of file RxDriverESP32.h.

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

src/sandbox/RxDriverESP32.h

Public Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ RxDriverESP32()

Member Function Documentation

◆ available()

◆ begin() [1/3]

◆ begin() [2/3]

◆ begin() [3/3]

◆ end()

◆ readBytes()

◆ rxTask()

◆ setFrameSize() [1/2]

◆ setFrameSize() [2/2]

◆ setRxBufferSize()

Field Documentation

◆ _codec

◆ _frameQueue

◆ _frameSize

◆ _freqHz

◆ _inFrame

◆ _lastSymbolTime

◆ _preambleBits

◆ _rxBufferSize

◆ _rxChannel

◆ _rxPin

◆ _stopTask

◆ _taskHandle

◆ _timeoutUs

◆ _useChecksum

◆ manchesterBits

◆ rxOverflow