A serial port (UART) for communication with other devices using Half-Duplex, allowing transmit and receive on a single shared transmit and receive line. More...

#include <SerialHalfDuplex.h>

Inherits mbed::Serial.

Public Member Functions
	SerialHalfDuplex (PinName tx, PinName rx)
	Create a half-duplex serial port, connected to the specified transmit and receive pins.
bool	readable ()
	Determine if there is a character available to read.
bool	writeable ()
	Determine if there is space available to write a character.
void	baud (int baudrate)
	Set the baud rate of the serial port.
void	format (int bits=8, Parity parity=SerialBase::None, int stop_bits=1)
	Set the transmission format used by the serial port.
void	attach (Callback< void()> func, IrqType type=RxIrq)
	Attach a function to call whenever a serial interrupt is generated.
template<typename T >
	MBED_DEPRECATED_SINCE ("mbed-os-5.1","The attach function does not support cv-qualifiers. Replaced by ""attach(callback(obj, method), type).") void attach(T *obj
	Attach a member function to call whenever a serial interrupt is generated.
	MBED_DEPRECATED_SINCE ("mbed-os-5.4","Replaced by FileHandle::seek") virtual off_t lseek(off_t offset
	Move the file position to a given offset from a given location.
void	set_flow_control (Flow type, PinName flow1=NC, PinName flow2=NC)
	Set the flow control type on the serial port.
int	write (const uint8_t *buffer, int length, const event_callback_t &callback, int event=SERIAL_EVENT_TX_COMPLETE)
	Begin asynchronous write using 8bit buffer.
int	write (const uint16_t *buffer, int length, const event_callback_t &callback, int event=SERIAL_EVENT_TX_COMPLETE)
	Begin asynchronous write using 16bit buffer.
void	abort_write ()
	Abort the on-going write transfer.
int	read (uint8_t *buffer, int length, const event_callback_t &callback, int event=SERIAL_EVENT_RX_COMPLETE, unsigned char char_match=SERIAL_RESERVED_CHAR_MATCH)
	Begin asynchronous reading using 8bit buffer.
int	read (uint16_t *buffer, int length, const event_callback_t &callback, int event=SERIAL_EVENT_RX_COMPLETE, unsigned char char_match=SERIAL_RESERVED_CHAR_MATCH)
	Begin asynchronous reading using 16bit buffer.
void	abort_read ()
	Abort the on-going read transfer.
int	set_dma_usage_tx (DMAUsage usage)
	Configure DMA usage suggestion for non-blocking TX transfers.
int	set_dma_usage_rx (DMAUsage usage)
	Configure DMA usage suggestion for non-blocking RX transfers.
Protected Member Functions
virtual void	lock ()
	Acquire exclusive access to this serial port.
virtual void	unlock ()
	Release exclusive access to this serial port.
virtual ssize_t	write (const void *buffer, size_t length)
	Write the contents of a buffer to a file.
virtual ssize_t	read (void *buffer, size_t length)
	Read the contents of a file into a buffer.
	MBED_DEPRECATED ("Invalid copy construction of a NonCopyable resource.") NonCopyable(const NonCopyable &)
	NonCopyable copy constructor.
	MBED_DEPRECATED ("Invalid copy assignment of a NonCopyable resource.") NonCopyable &operator
	NonCopyable copy assignment operator.
	MBED_DEPRECATED ("Invalid copy construction of a NonCopyable resource.") NonCopyable(const NonCopyable &)
	NonCopyable copy constructor.
	MBED_DEPRECATED ("Invalid copy assignment of a NonCopyable resource.") NonCopyable &operator
	NonCopyable copy assignment operator.
virtual int	close ()
	Close a file.
virtual off_t	seek (off_t offset, int whence)
	Move the file position to a given offset from from a given location.
virtual off_t	tell ()
	Get the file position of the file.
virtual void	rewind ()
	Rewind the file position to the beginning of the file.
virtual int	isatty ()
	Check if the file in an interactive terminal device.
virtual int	sync ()
	Flush any buffers associated with the file.
virtual off_t	size ()
	Get the size of the file.

Detailed Description

A serial port (UART) for communication with other devices using Half-Duplex, allowing transmit and receive on a single shared transmit and receive line.

Only one end should be transmitting at a time.

Both the tx and rx pin should be defined, and wired together. This is in addition to them being wired to the other serial device to allow both read and write functions to operate.

For Simplex and Full-Duplex Serial communication, see Serial()

Example:

 // Send a byte to a second HalfDuplex device, and read the response

 #include "mbed.h"

 // p9 and p10 should be wired together to form "a"
 // p28 and p27 should be wired together to form "b"
 // p9/p10 should be wired to p28/p27 as the Half Duplex connection

 SerialHalfDuplex a(p9, p10);
 SerialHalfDuplex b(p28, p27);

 void b_rx() { // second device response
     b.putc(b.getc() + 4);
 }

 int main() {
     b.attach(&b_rx);
     for (int c = 'A'; c < 'Z'; c++) {
         a.putc(c);
         printf("sent [%c]\n", c);
         wait(0.5);   // b should respond
         if (a.readable()) {
             printf("received [%c]\n", a.getc());
         }
     }
 }

Definition at line 57 of file SerialHalfDuplex.h.

Constructor & Destructor Documentation

SerialHalfDuplex	(	PinName	tx,
		PinName	rx
	)

Create a half-duplex serial port, connected to the specified transmit and receive pins.

These pins should be wired together, as well as to the target device

Parameters:

tx	Transmit pin
rx	Receive pin

Definition at line 14 of file SerialHalfDuplex.cpp.

Member Function Documentation

void abort_read ( void ) [inherited]

Abort the on-going read transfer.

Definition at line 210 of file SerialBase.cpp.

void abort_write ( void ) [inherited]

Abort the on-going write transfer.

Definition at line 200 of file SerialBase.cpp.

void attach	(	Callback< void()>	func,
		IrqType	type = `RxIrq`
	)		`[inherited]`

Attach a function to call whenever a serial interrupt is generated.

Parameters:

func	A pointer to a void function, or 0 to set as none
type	Which serial interrupt to attach the member function to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)

Definition at line 71 of file SerialBase.cpp.

void baud ( int baudrate ) [inherited]

Set the baud rate of the serial port.

Parameters:

baudrate The baudrate of the serial port (default = 9600).

Definition at line 43 of file SerialBase.cpp.

int close ( ) [protected, virtual, inherited]

Close a file.

Returns:: 0 on success, negative error code on failure

Implements FileHandle.

Definition at line 70 of file Stream.cpp.

void format	(	int	bits = `8`,
		Parity	parity = `SerialBase::None`,
		int	stop_bits = `1`
	)		`[inherited]`

Set the transmission format used by the serial port.

Parameters:

bits	The number of bits in a word (5-8; default = 8)
parity	The parity used (SerialBase::None, SerialBase::Odd, SerialBase::Even, SerialBase::Forced1, SerialBase::Forced0; default = SerialBase::None)
stop_bits	The number of stop bits (1 or 2; default = 1)

Definition at line 50 of file SerialBase.cpp.

int isatty ( ) [protected, virtual, inherited]

Check if the file in an interactive terminal device.

Returns:: True if the file is a terminal; False if the file is not a terminal; Negative error code on failure

Reimplemented from FileHandle.

Definition at line 115 of file Stream.cpp.

void lock ( void ) [protected, virtual, inherited]

Acquire exclusive access to this serial port.

Reimplemented from SerialBase.

Definition at line 39 of file Serial.cpp.

MBED_DEPRECATED ( "Invalid copy construction of a NonCopyable< Stream > resource." ) const [protected, inherited]

NonCopyable copy constructor.

A compile time warning is issued when this function is used and a runtime warning is printed when the copy construction of the non copyable happens.

If you see this warning, your code is probably doing something unspecified. Copy of non copyable resources can lead to resource leak and random error.

Definition at line 171 of file NonCopyable.h.

MBED_DEPRECATED ( "Invalid copy assignment of a NonCopyable< Stream > resource." ) [protected, inherited]

NonCopyable copy assignment operator.

A compile time warning is issued when this function is used and a runtime warning is printed when the copy construction of the non copyable happens.

If you see this warning, your code is probably doing something unspecified. Copy of non copyable resources can lead to resource leak and random error.

MBED_DEPRECATED ( "Invalid copy construction of a NonCopyable< FileBase > resource." ) const [protected, inherited]

NonCopyable copy constructor.

A compile time warning is issued when this function is used and a runtime warning is printed when the copy construction of the non copyable happens.

If you see this warning, your code is probably doing something unspecified. Copy of non copyable resources can lead to resource leak and random error.

Definition at line 171 of file NonCopyable.h.

MBED_DEPRECATED ( "Invalid copy assignment of a NonCopyable< FileBase > resource." ) [protected, inherited]

NonCopyable copy assignment operator.

A compile time warning is issued when this function is used and a runtime warning is printed when the copy construction of the non copyable happens.

If you see this warning, your code is probably doing something unspecified. Copy of non copyable resources can lead to resource leak and random error.

MBED_DEPRECATED_SINCE	(	"mbed-os-5.1"	,
		"The attach function does not support cv-qualifiers. Replaced by ""attach(callback(obj, method), type)."
	)		`[inherited]`

Attach a member function to call whenever a serial interrupt is generated.

Parameters:

obj	pointer to the object to call the member function on
method	pointer to the member function to be called
type	Which serial interrupt to attach the member function to (Seriall::RxIrq for receive, TxIrq for transmit buffer empty)

MBED_DEPRECATED_SINCE	(	"mbed-os-5.4"	,
		"Replaced by FileHandle::seek"
	)		`[inherited]`

Move the file position to a given offset from a given location.

Parameters:

offset	The offset from whence to move to
whence	SEEK_SET for the start of the file, SEEK_CUR for the current file position, or SEEK_END for the end of the file.

Returns:: new file position on success, -1 on failure or unsupported

int read	(	uint8_t *	buffer,
		int	length,
		const event_callback_t &	callback,
		int	event = `SERIAL_EVENT_RX_COMPLETE`,
		unsigned char	char_match = `SERIAL_RESERVED_CHAR_MATCH`
	)		`[inherited]`

Begin asynchronous reading using 8bit buffer.

The completition invokes registred RX event callback.

This function locks the deep sleep until any event has occured

Parameters:

buffer	The buffer where received data will be stored
length	The buffer length in bytes
callback	The event callback function
event	The logical OR of RX events
char_match	The matching character

Definition at line 238 of file SerialBase.cpp.

ssize_t read	(	void *	buffer,
		size_t	size
	)		`[protected, virtual, inherited]`

Read the contents of a file into a buffer.

Devices acting as FileHandles should follow POSIX semantics:

* if no data is available, and non-blocking set return -EAGAIN * if no data is available, and blocking set, wait until data is available * If any data is available, call returns immediately

Parameters:

buffer	The buffer to read in to
size	The number of bytes to read

Returns:: The number of bytes read, 0 at end of file, negative error on failure

Implements FileHandle.

Definition at line 89 of file Stream.cpp.

int read	(	uint16_t *	buffer,
		int	length,
		const event_callback_t &	callback,
		int	event = `SERIAL_EVENT_RX_COMPLETE`,
		unsigned char	char_match = `SERIAL_RESERVED_CHAR_MATCH`
	)		`[inherited]`

Begin asynchronous reading using 16bit buffer.

The completition invokes registred RX event callback.

This function locks the deep sleep until any event has occured

Parameters:

buffer	The buffer where received data will be stored
length	The buffer length in bytes
callback	The event callback function
event	The logical OR of RX events
char_match	The matching character

Definition at line 248 of file SerialBase.cpp.

bool readable ( ) [inherited]

Determine if there is a character available to read.

Returns:: 1 if there is a character available to read, 0 otherwise

Reimplemented from SerialBase.

Definition at line 89 of file Serial.h.

void rewind ( ) [protected, virtual, inherited]

Rewind the file position to the beginning of the file.

Note:: This is equivalent to seek(0, SEEK_SET)

Reimplemented from FileHandle.

Definition at line 112 of file Stream.cpp.

off_t seek	(	off_t	offset,
		int	whence
	)		`[protected, virtual, inherited]`

Move the file position to a given offset from from a given location.

Parameters:

offset	The offset from whence to move to
whence	The start of where to seek SEEK_SET to start from beginning of file, SEEK_CUR to start from current position in file, SEEK_END to start from end of file

Returns:: The new offset of the file, negative error code on failure

Implements FileHandle.

Definition at line 104 of file Stream.cpp.

int set_dma_usage_rx ( DMAUsage usage ) [inherited]

Configure DMA usage suggestion for non-blocking RX transfers.

Parameters:

usage The usage DMA hint for peripheral

Returns:: Zero if the usage was set, -1 if a transaction is on-going

Definition at line 229 of file SerialBase.cpp.

int set_dma_usage_tx ( DMAUsage usage ) [inherited]

Configure DMA usage suggestion for non-blocking TX transfers.

Parameters:

usage The usage DMA hint for peripheral

Returns:: Zero if the usage was set, -1 if a transaction is on-going

Definition at line 220 of file SerialBase.cpp.

void set_flow_control	(	Flow	type,
		PinName	flow1 = `NC`,
		PinName	flow2 = `NC`
	)		`[inherited]`

Set the flow control type on the serial port.

Parameters:

type	the flow control type (Disabled, RTS, CTS, RTSCTS)
flow1	the first flow control pin (RTS for RTS or RTSCTS, CTS for CTS)
flow2	the second flow control pin (CTS for RTSCTS)

Reimplemented in UARTSerial.

Definition at line 147 of file SerialBase.cpp.

off_t size ( ) [protected, virtual, inherited]

Get the size of the file.

Returns:: Size of the file in bytes

Reimplemented from FileHandle.

Definition at line 123 of file Stream.cpp.

int sync ( ) [protected, virtual, inherited]

Flush any buffers associated with the file.

Returns:: 0 on success, negative error code on failure

Reimplemented from FileHandle.

Definition at line 119 of file Stream.cpp.

off_t tell ( ) [protected, virtual, inherited]

Get the file position of the file.

Note:: This is equivalent to seek(0, SEEK_CUR)

Returns:: The current offset in the file, negative error code on failure

Reimplemented from FileHandle.

Definition at line 108 of file Stream.cpp.

void unlock ( void ) [protected, virtual, inherited]

Release exclusive access to this serial port.

Reimplemented from SerialBase.

Definition at line 43 of file Serial.cpp.

int write	(	const uint8_t *	buffer,
		int	length,
		const event_callback_t &	callback,
		int	event = `SERIAL_EVENT_TX_COMPLETE`
	)		`[inherited]`

Begin asynchronous write using 8bit buffer.

The completition invokes registered TX event callback

This function locks the deep sleep until any event has occured

Parameters:

buffer	The buffer where received data will be stored
length	The buffer length in bytes
callback	The event callback function
event	The logical OR of TX events

Definition at line 173 of file SerialBase.cpp.

ssize_t write	(	const void *	buffer,
		size_t	size
	)		`[protected, virtual, inherited]`

Write the contents of a buffer to a file.

Parameters:

buffer	The buffer to write from
size	The number of bytes to write

Returns:: The number of bytes written, negative error on failure

Implements FileHandle.

Definition at line 74 of file Stream.cpp.

int write	(	const uint16_t *	buffer,
		int	length,
		const event_callback_t &	callback,
		int	event = `SERIAL_EVENT_TX_COMPLETE`
	)		`[inherited]`

Begin asynchronous write using 16bit buffer.

The completition invokes registered TX event callback

This function locks the deep sleep until any event has occured

Parameters:

buffer	The buffer where received data will be stored
length	The buffer length in bytes
callback	The event callback function
event	The logical OR of TX events

Definition at line 182 of file SerialBase.cpp.

bool writeable ( ) [inherited]

Determine if there is space available to write a character.

Returns:: 1 if there is space to write a character, 0 otherwise

Reimplemented from SerialBase.

Definition at line 97 of file Serial.h.

Type:	Program
Mbed OS support:	Mbed OS
Created:	23 Feb 2019
Imports:	43
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	1

SerialHalfDuplex Class Reference

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

SerialHalfDuplex Class Reference

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

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