SPIRegAudioSlave Class Reference

SPI audio slave based on the TinySPISlave library: the master controls us via a small register map (see SPIRegAudioRegisters.h): More...

#include <SPIRegAudioSlave.h>

Inheritance diagram for SPIRegAudioSlave:

Collaboration diagram for SPIRegAudioSlave:

Public Member Functions
	SPIRegAudioSlave (BaseBuffer< uint8_t > &buffer)
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
virtual AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfoOut ()
int	available () override
	Readable audio bytes.
int	availableForWrite () override
	Free space in the buffer: this is the value provided to the master.
virtual bool	begin ()
bool	begin (SPIRegAudioSlaveConfig cfg=SPIRegAudioSlaveConfig())
virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.
void	end () override
virtual void	flush () override
bool	isActive () const
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
const char *	mime () override
const char *	mimeType ()
	Mime type defined by the master (empty if not set)
virtual	operator bool ()
uint32_t	overflowBytes () const
	Number of audio bytes dropped because the master ignored the flow control.
size_t	readBytes (uint8_t *data, size_t len) override
virtual size_t	readSilence (uint8_t *buffer, size_t length)
	Source to generate silence: just sets the buffer to 0.
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
virtual void	setAudioInfo (AudioInfo newInfo) override
	Defines the input AudioInfo.
void	setMimeCallback (void(*cb)(const char *mime, void *ctx), void *ctx=nullptr)
void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active)
void	setWriteBufferSize (int size)
void	update ()
	Call from loop(): applies AudioInfo / mime changes made by the master.
virtual size_t	write (const uint8_t *data, size_t len) override
virtual size_t	write (uint8_t ch) override
virtual void	writeSilence (size_t len)
	Writes len bytes of silence (=0).

Protected Member Functions
virtual int	not_supported (int out, const char *msg="")
void	notifyAudioChange (AudioInfo info)
void	onFrame (size_t len)
	Processes one frame: runs in ISR / SPI task context!
void	refillReadBuffer ()
	Refill small read buffer (e.g. 8 bytes) to avoid single byte reads when calling read()
void	stageReply (uint8_t addr, size_t want)
void	storeWrite (uint8_t addr, size_t len)

Static Protected Member Functions
static void	decodeInfo (const uint8_t *in, AudioInfo &out)
static void	encodeInfo (const AudioInfo &in, uint8_t *out)
static void	frameThunk (size_t len, void *self)

Protected Attributes
int	_timeout = 10
bool	active = false
SPIRegAudioSlaveConfig	config
AudioInfo	info
uint8_t	info_raw [SPIREG_AUDIO_INFO_SIZE]
bool	is_notify_active = true
void(*	mime_cb )(const char *, void *) = nullptr
void *	mime_ctx = nullptr
char	mime_raw [SPIREG_MIME_SIZE]
char	mime_str [SPIREG_MIME_SIZE] = {0}
Vector< AudioInfoSupport * >	notify_vector
volatile uint32_t	overflow_bytes = 0
BaseBuffer< uint8_t > *	p_buffer = nullptr
volatile bool	pending_info = false
volatile bool	pending_mime = false
TinySPISlave	spi
RingBuffer< uint8_t >	tmp_in {0}
RingBuffer< uint8_t >	tmp_out {0}
int	write_buffer_size = MAX_SINGLE_CHARS

Detailed Description

SPI audio slave based on the TinySPISlave library: the master controls us via a small register map (see SPIRegAudioRegisters.h):

• SPIREG_AUDIO_INFO: sample rate, channels and bits per sample
• SPIREG_MIME: mime type of the audio data
• SPIREG_AVAILABLE: free space in our buffer (the master uses it for flow control)
• SPIREG_DATA: the audio data

The received audio is stored in the provided buffer; read it with readBytes() or copy it to an output with StreamCopy. Call update() from loop(): it applies format changes (AudioInfo notifications) in the application context. The SPI frames themselves are processed in the interrupt (RP2040/STM32) or in the TinySPISlave task (ESP32), so the buffer should be safe for one writer (SPI) and one reader (loop), e.g. a RingBuffer.

Note

Requires the TinySPISlave library (ESP32, RP2040/RP2350, STM32).

RingBuffer<uint8_t> buffer(8 * 1024);
SPIRegAudioSlave slave(buffer);
auto cfg = SPIRegAudioSlaveConfig();
cfg.sck = 18; cfg.miso = 19; cfg.mosi = 23; cfg.cs = 5;
slave.begin(cfg);
slave.addNotifyAudioChange(i2s);  // format is set by the master
StreamCopy copier(i2s, slave);
void loop() { slave.update(); copier.copy(); }

Constructor & Destructor Documentation

SPIRegAudioSlave()

SPIRegAudioSlave ( BaseBuffer< uint8_t > &  buffer )

inline

Member Function Documentation

addNotifyAudioChange()

virtual void addNotifyAudioChange ( AudioInfoSupport &  bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, EncodedAudioOutput, EncodedAudioStream, AACDecoderFDK, DecoderBasic, CodecChain, MP3DecoderHelix, MP3DecoderMAD, OggContainerDecoder, RTSPClient< TcpClient, UdpSocket >, Pipeline, and Pipeline::ModifyingStreamAdapter.

audioInfo()

virtual AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

Reimplemented in JupyterAudioT< T >, MozziStream, TimerCallbackAudioStream, EncodedAudioStream, PureDataStream, AdapterAudioOutputToAudioStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, and InputMerge< T >.

audioInfoOut()

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

provides the actual output AudioInfo: this is usually the same as audioInfo() unless we use a transforming stream

Reimplemented in MP3EncoderShine, PureDataStream, PWMAudioOutput< PWMDriverT >, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, FormatConverterStream, Pipeline, ResampleStream, ResampleStreamT< TInterpolator >, and SupportedRatesStream.

available()

int available ( )

inlineoverridevirtual

Readable audio bytes.

Reimplemented from BaseStream.

availableForWrite()

int availableForWrite ( )

inlineoverridevirtual

Free space in the buffer: this is the value provided to the master.

Reimplemented from BaseStream.

begin() [1/2]

virtual bool begin ( )

inlinevirtualinherited

Reimplemented in AudioOutputWithCallback, AudioMP34DT05, I2SCodecStream, MozziStream, PureDataStream, SPDIFOutput, VS1053Stream, WM8960Stream, AdaptiveResamplingStream, AudioLoRa, ESPNowStream, USBAudioDeviceBase, USBAudioHostBase, VBANStream, FrequencyDetectorAutoCorrelation, GoertzelStream, AudioEffectStreamT< T >, AudioEffectStream, Equalizer3BandsT< T >, Equalizer3BandsPerChannelT< T >, I2SStream, AudioTimeSourceStream, AudioStreamWrapper, TimerCallbackAudioStream, ResampleStreamT< TInterpolator >, FileLoopT< FileType >, FileLoopT< File >, EncodedAudioStream, AudioBoardStream, AudioKitStream, MiniAudioStream, PortAudioStream, StdioStream, HLSStreamT< URLStream >, NRF24Stream, ReedSolomonFEC< bytecount, additional_bytes >, AutomaticGainControlStream, MeasuringStream, QualityAnalysisStream, VolumeStream, AnalogAudioStream, AdapterAudioOutputToAudioStream, TimedStream, MemoryStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, ProgressStream, Throttle, InputMerge< T >, CallbackStream, FilteredStream< T, TF >, FilteredStream< int16_t, int16_t >, VolumeMeter, AudioInputMonitor, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, FormatConverterStream, CatStream, QueueStream< T >, QueueStream< uint8_t >, DynamicMemoryStream, Pipeline, Pipeline::ModifyingStreamAdapter, ResampleStream, SupportedRatesStream, AudioFFTBase, and EqualizerNBands< SampleT, AccT, NUM_TAPS, NUM_BANDS >.

begin() [2/2]

bool begin ( SPIRegAudioSlaveConfig  cfg = SPIRegAudioSlaveConfig() )

inline

clearNotifyAudioChange()

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

decodeInfo()

static void decodeInfo ( const uint8_t *  in, AudioInfo &  out  )

inlinestaticprotected

encodeInfo()

static void encodeInfo ( const AudioInfo &  in, uint8_t *  out  )

inlinestaticprotected

end()

void end ( )

inlineoverridevirtual

Reimplemented from BaseStream.

flush()

virtual void flush ( )

inlineoverridevirtualinherited

Reimplemented from Print.

Reimplemented in PureDataStream, URLStreamBufferedT< T >, URLStreamBufferedT< ICYStream >, ReformatBaseStream, AudioStreamWrapper, ResampleStream, EncodedAudioStream, BLESerialClientBase, URLStream, BufferedTaskStream, AutomaticGainControlStream, MeasuringStream, QualityAnalysisStream, VolumeStream, AudioEffectStreamT< T >, AudioEffectStream, Equalizer3BandsT< T >, Equalizer3BandsPerChannelT< T >, I2SStream, TimedStream, MemoryStream, RingBufferStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, BufferedStream, FilteredStream< T, TF >, FilteredStream< int16_t, int16_t >, QueueStream< T >, QueueStream< uint8_t >, FadeStream, Pipeline::ModifyingStreamAdapter, SupportedRatesStream, and EqualizerNBands< SampleT, AccT, NUM_TAPS, NUM_BANDS >.

frameThunk()

static void frameThunk ( size_t  len, void *  self  )

inlinestaticprotected

isActive()

bool isActive ( ) const

inline

isNotifyActive()

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

mime()

const char * mime ( )

inlineoverridevirtual

Mime type defined by the master (nullptr if not set): this allows to use the slave as source for the MultiDecoder

Implements MimeSource.

mimeType()

const char * mimeType ( )

inline

Mime type defined by the master (empty if not set)

not_supported()

virtual int not_supported ( int  out, const char *  msg = ""  )

inlineprotectedvirtualinherited

notifyAudioChange()

void notifyAudioChange ( AudioInfo  info )

inlineprotectedinherited

onFrame()

void onFrame ( size_t  len )

inlineprotected

Processes one frame: runs in ISR / SPI task context!

operator bool()

virtual operator bool ( )

inlinevirtualinherited

Reimplemented in A2DPStream, ICYStreamT< T >, PortAudioStream, BLESerialStream, URLStream, USBAudioStreamBase, I2SStream, AdapterAudioOutputToAudioStream, TimedStream, MemoryStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, Pipeline, and AudioFFTBase.

overflowBytes()

uint32_t overflowBytes ( ) const

inline

Number of audio bytes dropped because the master ignored the flow control.

readBytes()

size_t readBytes ( uint8_t *  data, size_t  len  )

inlineoverridevirtual

Reimplemented from AudioStream.

readSilence()

virtual size_t readSilence ( uint8_t *  buffer, size_t  length  )

inlinevirtualinherited

Source to generate silence: just sets the buffer to 0.

refillReadBuffer()

void refillReadBuffer ( )

inlineprotectedinherited

Refill small read buffer (e.g. 8 bytes) to avoid single byte reads when calling read()

removeNotifyAudioChange()

virtual bool removeNotifyAudioChange ( AudioInfoSupport &  bi )

inlinevirtualinherited

Removes a target in order not to be notified about audio changes.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

setAudioInfo()

virtual void setAudioInfo ( AudioInfo  info )

inlineoverridevirtualinherited

Defines the input AudioInfo.

Implements AudioInfoSupport.

Reimplemented in VS1053Stream, WM8960Stream, AutomaticGainControlStream, VolumeStream, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, MiniAudioStream, PortAudioStream, I2SCodecStream, MozziStream, SPDIFOutput, AudioLoRa, AnalogAudioStream, I2SStream, TimerCallbackAudioStream, MDFEchoCancellationStream< T, SampleType >, AudioKitStream, NRF24Stream, SPIAudioSlave, USBAudioDeviceBase, USBAudioHostBase, VBANStream, GoertzelStream, MeasuringStream, QualityAnalysisStream, Equalizer3BandsT< T >, Equalizer3BandsPerChannelT< T >, AdapterAudioOutputToAudioStream, TimedStream, ProgressStream, CallbackStream, VolumeMeter, AudioInputMonitor, FormatConverterStream, FadeStream, Pipeline::ModifyingStreamAdapter, AudioFFTBase, EncodedAudioStream, PureDataStream, BLESerialStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, Pipeline, ResampleStream, ResampleStreamT< TInterpolator >, and SupportedRatesStream.

setMimeCallback()

void setMimeCallback ( void(*)(const char *mime, void *ctx)  cb, void *  ctx = nullptr  )

inline

Callback which is called from update() when the master has defined a (new) mime type: e.g. to restart the decoder

setNotifyActive()

void setNotifyActive ( bool  flag )

inlineinherited

Deactivate/Reactivate automatic AudioInfo updates: (default is active)

setWriteBufferSize()

void setWriteBufferSize ( int  size )

inlineinherited

stageReply()

void stageReply ( uint8_t  addr, size_t  want  )

inlineprotected

storeWrite()

void storeWrite ( uint8_t  addr, size_t  len  )

inlineprotected

update()

void update ( )

inline

Call from loop(): applies AudioInfo / mime changes made by the master.

write() [1/2]

virtual size_t write ( const uint8_t *  data, size_t  len  )

inlineoverridevirtualinherited

Implements BaseStream.

Reimplemented in URLStream, LMSEchoCancellationStream< T >, MDFEchoCancellationStream< T, SampleType >, ESP3288AudioOutput, I2SCodecStream, MozziStream, PureDataStream, SPDIFOutput, AudioLoRa, USBAudioStreamBase, I2SStream, AudioStreamWrapper, ConverterStream< T >, EncodedAudioStream, FaustStream< DSP >, AudioKitStream, MiniAudioStream, PortAudioStream, TfLiteAudioStream, VS1053Stream, A2DPStream, AdaptiveResamplingStream, BLESerialServerBase, BLESerialClientBase, BufferedTaskStream, URLStreamESP32, NRF24Stream, SPIAudioSlave, VBANStream, AutomaticGainControlStream, FrequencyDetectorAutoCorrelation, FrequencyDetectorZeroCrossing, GoertzelStream, MeasuringStream, QualityAnalysisStream, VolumeStream, AnalogAudioStream, AudioEffectStreamT< T >, AudioEffectStream, Equalizer3BandsT< T >, Equalizer3BandsPerChannelT< T >, AdapterAudioOutputToAudioStream, TimedStream, AudioTimeSourceStream, MemoryStream, RingBufferStream, BufferedStream, ProgressStream, Throttle, CallbackStream, FilteredStream< T, TF >, FilteredStream< int16_t, int16_t >, VolumeMeter, AudioInputMonitor, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, FormatConverterStream, FadeStream, Pipeline, Pipeline::ModifyingStreamAdapter, ResampleStream, ResampleStreamT< TInterpolator >, SupportedRatesStream, AudioFFTBase, EqualizerNBands< SampleT, AccT, NUM_TAPS, NUM_BANDS >, TfLiteAudioStreamBase, WM8960Stream, AnalogDriverESP32V1::IO16Bit, and AnalogDriverESP32V2::IO16Bit.

write() [2/2]

virtual size_t write ( uint8_t  ch )

inlineoverridevirtualinherited

Reimplemented in MemoryStream, AudioStreamWrapper, BufferedTaskStream, RingBufferStream, BufferedStream, and URLStream.

writeSilence()

virtual void writeSilence ( size_t  len )

inlinevirtualinherited

Writes len bytes of silence (=0).

Member Data Documentation

_timeout

int _timeout = 10

protectedinherited

active

bool active = false

protected

config

SPIRegAudioSlaveConfig config

protected

info

AudioInfo info

protectedinherited

info_raw

uint8_t info_raw[SPIREG_AUDIO_INFO_SIZE]

protected

is_notify_active

bool is_notify_active = true

protectedinherited

mime_cb

void(* mime_cb) (const char *, void *) = nullptr

protected

mime_ctx

void* mime_ctx = nullptr

protected

mime_raw

char mime_raw[SPIREG_MIME_SIZE]

protected

mime_str

char mime_str[SPIREG_MIME_SIZE] = {0}

protected

notify_vector

Vector<AudioInfoSupport*> notify_vector

protectedinherited

overflow_bytes

volatile uint32_t overflow_bytes = 0

protected

p_buffer

BaseBuffer<uint8_t>* p_buffer = nullptr

protected

pending_info

volatile bool pending_info = false

protected

pending_mime

volatile bool pending_mime = false

protected

spi

TinySPISlave spi

protected

tmp_in

RingBuffer<uint8_t> tmp_in {0}

protectedinherited

tmp_out

RingBuffer<uint8_t> tmp_out {0}

protectedinherited

write_buffer_size

int write_buffer_size = MAX_SINGLE_CHARS

protectedinherited

---

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

• src/AudioTools/Communication/SPI/SPIRegAudioSlave.h