#include <USBAudio.h>

Inherits USBDevice.

Public Types
enum	AudioSampleCorrectType
	Audio Jitter value. More...
Public Member Functions
	USBAudio (uint32_t frequency_in=48000, uint8_t channel_nb_in=1, uint32_t frequency_out=8000, uint8_t channel_nb_out=1, uint16_t vendor_id=0x7bb8, uint16_t product_id=0x1111, uint16_t product_release=0x0100)
	Constructor.
float	getVolume ()
	Get current volume between 0.0 and 1.0.
bool	read (uint8_t *buf)
	Read an audio packet.
bool	readNB (uint8_t *buf)
	Try to read an audio packet.
uint32_t	readSync (uint8_t *buf)
	read last received packet if some.
bool	write (uint8_t *buf)
	Write an audio packet.
void	writeSync (uint8_t *buf, AudioSampleCorrectType jitter_nb=NoCorrection)
	Write packet in endpoint fifo.
bool	readWrite (uint8_t buf_read, uint8_t buf_write)
	Write and read an audio packet at the same time (on the same frame)
void	attach (void(*fptr)(void))
	attach a handler to update the volume
void	attachTx (void(*fptr)(void))
	attach a handler to Tx Done
void	attachRx (void(*fptr)(void))
	attach a handler to Rx Done
template<typename T >
void	attach (T tptr, void(T::mptr)(void))
	Attach a nonstatic void/void member function to update the volume.
template<typename T >
void	attachTx (T tptr, void(T::mptr)(void))
	Attach a nonstatic void/void member function to Tx Done.
template<typename T >
void	attachRx (T tptr, void(T::mptr)(void))
	Attach a nonstatic void/void member function to Rx Done.
void	attach (Callback< void()> &cb)
	Attach a Callback to update the volume.
void	attachTx (Callback< void()> &cb)
	attach a Callback to Tx Done
void	attachRx (Callback< void()> &cb)
	attach a Callback to Rx Done

Detailed Description

USBAudio example.

 #include "mbed.h"
 #include "USBAudio.h"

 Serial pc(USBTX, USBRX);

 // frequency: 48 kHz
 #define FREQ 48000

 // 1 channel: mono
 #define NB_CHA 1

 // length of an audio packet: each ms, we receive 48 * 16bits ->48 * 2 bytes. as there is one channel, the length will be 48 * 2 * 1
 #define AUDIO_LENGTH_PACKET 48 * 2 * 1

 // USBAudio
 USBAudio audio(FREQ, NB_CHA);

 int main() {
    int16_t buf[AUDIO_LENGTH_PACKET/2];

    while (1) {
        // read an audio packet
        audio.read((uint8_t *)buf);


        // print packet received
        pc.printf("recv: ");
        for(int i = 0; i < AUDIO_LENGTH_PACKET/2; i++) {
            pc.printf("%d ", buf[i]);
        }
        pc.printf("\r\n");
    }
 }

Definition at line 69 of file USBAudio.h.

Member Enumeration Documentation

enum AudioSampleCorrectType

Audio Jitter value.

Definition at line 127 of file USBAudio.h.

Constructor & Destructor Documentation

USBAudio	(	uint32_t	frequency_in = `48000`,
		uint8_t	channel_nb_in = `1`,
		uint32_t	frequency_out = `8000`,
		uint8_t	channel_nb_out = `1`,
		uint16_t	vendor_id = `0x7bb8`,
		uint16_t	product_id = `0x1111`,
		uint16_t	product_release = `0x0100`
	)

Constructor.

Parameters:

frequency_in	frequency in Hz (default: 48000)
channel_nb_in	channel number (1 or 2) (default: 1)
frequency_out	frequency in Hz (default: 8000)
channel_nb_out_in	channel number (1 or 2) (default: 1)
vendor_id	Your vendor_id
product_id	Your product_id
product_release	Your preoduct_release

Definition at line 25 of file USBAudio.cpp.

Member Function Documentation

void attach	(	T *	tptr,
		void(T::*)(void)	mptr
	)

Attach a nonstatic void/void member function to update the volume.

Parameters:

tptr	Object pointer
mptr	Member function pointer

Definition at line 181 of file USBAudio.h.

void attach ( void(*)(void) fptr )

attach a handler to update the volume

Parameters:

function Function to attach

Definition at line 154 of file USBAudio.h.

void attach ( Callback< void()> & cb )

Attach a Callback to update the volume.

Parameters:

cb	Callback to attach

Definition at line 210 of file USBAudio.h.

void attachRx ( Callback< void()> & cb )

attach a Callback to Rx Done

Parameters:

cb	Callback to attach

Definition at line 226 of file USBAudio.h.

void attachRx ( void(*)(void) fptr )

attach a handler to Rx Done

Parameters:

function Function to attach

Definition at line 170 of file USBAudio.h.

void attachRx	(	T *	tptr,
		void(T::*)(void)	mptr
	)

Attach a nonstatic void/void member function to Rx Done.

Parameters:

tptr	Object pointer
mptr	Member function pointer

Definition at line 201 of file USBAudio.h.

void attachTx ( void(*)(void) fptr )

attach a handler to Tx Done

Parameters:

function Function to attach

Definition at line 162 of file USBAudio.h.

void attachTx	(	T *	tptr,
		void(T::*)(void)	mptr
	)

Attach a nonstatic void/void member function to Tx Done.

Parameters:

tptr	Object pointer
mptr	Member function pointer

Definition at line 191 of file USBAudio.h.

void attachTx ( Callback< void()> & cb )

attach a Callback to Tx Done

Parameters:

cb	Callback to attach

Definition at line 218 of file USBAudio.h.

float getVolume ( )

Get current volume between 0.0 and 1.0.

Returns:: volume

Definition at line 134 of file USBAudio.cpp.

bool read ( uint8_t * buf )

Read an audio packet.

During a frame, only a single reading (you can't write and read an audio packet during the same frame)can be done using this method. Warning: Blocking

Parameters:

buf	pointer on a buffer which will be filled with an audio packet

Returns:: true if successfull

Definition at line 65 of file USBAudio.cpp.

bool readNB ( uint8_t * buf )

Try to read an audio packet.

During a frame, only a single reading (you can't write and read an audio packet during the same frame)can be done using this method. Warning: Non Blocking

Parameters:

buf	pointer on a buffer which will be filled if an audio packet is available

Returns:: true if successfull

Definition at line 73 of file USBAudio.cpp.

uint32_t readSync ( uint8_t * buf )

read last received packet if some.

Parameters:

buf	pointer on a buffer which will be filled if an audio packet is available

Returns:: the packet length

Definition at line 127 of file USBAudio.cpp.

bool readWrite	(	uint8_t *	buf_read,
		uint8_t *	buf_write
	)

Write and read an audio packet at the same time (on the same frame)

Parameters:

buf_read	pointer on a buffer which will be filled with an audio packet
buf_write	pointer on the audio packet which will be sent

Returns:: true if successful

Definition at line 85 of file USBAudio.cpp.

bool write ( uint8_t * buf )

Write an audio packet.

During a frame, only a single writing (you can't write and read an audio packet during the same frame)can be done using this method.

Parameters:

buf	pointer on the audio packet which will be sent

Returns:: true if successful

Definition at line 103 of file USBAudio.cpp.

void writeSync	(	uint8_t *	buf,
		AudioSampleCorrectType	jitter_nb = `NoCorrection`
	)

Write packet in endpoint fifo.

assuming tx fifo is empty

Parameters:

buf	pointer on the audio packet which will be sent
jitter_nb	: AudioSampleCorrecttype

Definition at line 118 of file USBAudio.cpp.

Type:	Program
Mbed OS support:	Mbed OS
Created:	13 Apr 2018
Imports:	1
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	1

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USBAudio Class Reference

Public Types

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Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

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Important changes to repositories hosted on mbed.com

USBAudio Class Reference

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

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