Class daisy::SaiHandle¶

ClassList > daisy > SaiHandle

#include <sai.h>

Classes¶

Type	Name
struct	Config

Public Types¶

Type	Name
typedef void(*	CallbackFunctionPtr
enum	Result

Public Functions¶

Type	Name
Result	DeInit ()
float	GetBlockRate ()
size_t	GetBlockSize ()
const Config &	GetConfig () const
size_t	GetOffset () const
float	GetSampleRate ()
Result	Init (const Config & config)
bool	IsInitialized () const
	SaiHandle ()
	SaiHandle (const SaiHandle & other) = default
Result	StartDma (int32_t * buffer_rx, int32_t * buffer_tx, size_t size, CallbackFunctionPtr callback)
Result	StopDma ()
SaiHandle &	operator= (const SaiHandle & other) = default

Detailed Description¶

Support for I2S Audio Protocol with different bit-depth, samplerate options Allows for master or slave, as well as freedom of selecting direction, and other behavior for each peripheral, and block.

DMA Transfer commands must use buffers located within non-cached memory or use cache maintenance To declare an unitialized global element in the DMA memory section: int32_t DSY_DMA_BUFFER_SECTOR my_buffer[96];

Callback functions will be called once per half of the buffer. In the above example, the callback function would be called once for every 48 samples.

Use SAI Handle like this:

SaiHandle::Config sai_config; sai_config.periph = SaiHandle::Config::Peripheral::SAI_1; sai_config.sr = SaiHandle::Config::SampleRate::SAI_48KHZ; sai_config.bit_depth = SaiHandle::Config::BitDepth::SAI_24BIT; sai_config.a_sync = SaiHandle::Config::Sync::MASTER; sai_config.b_sync = SaiHandle::Config::Sync::SLAVE; sai_config.a_dir = SaiHandle::Config::Direction::RECEIVE; sai_config.b_dir = SaiHandle::Config::Direction::TRANSMIT; sai_config.pin_config.fs = {DSY_GPIOE, 4}; sai_config.pin_config.mclk = {DSY_GPIOE, 2}; sai_config.pin_config.sck = {DSY_GPIOE, 5}; sai_config.pin_config.sa = {DSY_GPIOE, 6}; sai_config.pin_config.sb = {DSY_GPIOE, 3}; // Then Initialize SaiHandle sai; sai.Init(sai_config); // Now you can use it: sai.StartDma(. . .);

Public Types Documentation¶

typedef CallbackFunctionPtr¶

typedef void(* daisy::SaiHandle::CallbackFunctionPtr) (int32_t *in, int32_t *out, size_t size);

Callback Function to be called when DMA transfer is complete and half complete. This callback is prepared however the data is transmitted/received from the device. For example, using an AK4556 the data will be interleaved 24bit MSB Justified

The hid/audio class will be allow for type conversions, de-interleaving, etc.

enum Result¶

enum daisy::SaiHandle::Result {
    OK,
    ERR
};

Return values for SAI functions

Public Functions Documentation¶

function DeInit¶

Result daisy::SaiHandle::DeInit ()

Deinitializes an SAI peripheral

function GetBlockRate¶

float daisy::SaiHandle::GetBlockRate ()

Returns the Block Rate of the current stream based on the size of the buffer passed in, and the current samplerate.

function GetBlockSize¶

size_t daisy::SaiHandle::GetBlockSize ()

Returns the number of samples per audio block Calculated as Buffer Size / 2 / number of channels

function GetConfig¶

const  Config & daisy::SaiHandle::GetConfig () const

Returns the current configuration

function GetOffset¶

size_t daisy::SaiHandle::GetOffset () const

Returns the current offset within the SAI buffer, will be either 0 or size/2

function GetSampleRate¶

float daisy::SaiHandle::GetSampleRate ()

Returns the samplerate based on the current configuration

function Init¶

Result daisy::SaiHandle::Init (
    const  Config & config
)

Initializes an SAI peripheral

function IsInitialized¶

inline bool daisy::SaiHandle::IsInitialized () const

function SaiHandle [½]¶

inline daisy::SaiHandle::SaiHandle ()

function SaiHandle [2/2]¶

daisy::SaiHandle::SaiHandle (
    const  SaiHandle & other
) = default

function StartDma¶

Result daisy::SaiHandle::StartDma (
    int32_t * buffer_rx,
    int32_t * buffer_tx,
    size_t size,
    CallbackFunctionPtr callback
)

Starts Rx and Tx in Circular Buffer Mode The callback will be called when half of the buffer is ready, and will handle size/2 samples per callback.

function StopDma¶

Result daisy::SaiHandle::StopDma ()

Stops the DMA stream for the SAI blocks in use.

function operator=¶

SaiHandle & daisy::SaiHandle::operator= (
    const  SaiHandle & other
) = default

The documentation for this class was generated from the following file external-docs/libDaisy/src/per/sai.h