STM32 hardware UART. More...

#include <Serial.h>

Inheritance diagram for Uart:

Public Member Functions
	Uart (pin_size_t _rx, pin_size_t _tx, pin_size_t _rts=NUM_DIGITAL_PINS, pin_size_t _cts=NUM_DIGITAL_PINS)
	Create a UART from Arduino digital pin numbers.

	Uart (PinName _rx, PinName _tx, PinName _rts=NC, PinName _cts=NC)
	Create a UART from STM32 pin names.

	Uart (void *peripheral, HalfDuplexMode_t halfDuplex=HALF_DUPLEX_DISABLED)
	Create a UART from an STM32 USART/UART peripheral.

	Uart (pin_size_t _rxtx)
	Create a half-duplex UART on a single digital pin.

	Uart (PinName _rxtx)
	Create a half-duplex UART on a single STM32 pin.

void	begin (unsigned long baud) override
	Start the UART with 8 data bits, no parity and 1 stop bit (SERIAL_8N1).

void	begin (unsigned long baud, uint16_t config) override
	Start the UART with the given baud rate and frame format.

void	end () override
	Wait for pending transmission, stop the UART, release its pins and clear the receive buffer.

int	available (void) override
	Get the number of bytes available to read.

int	peek (void) override
	Read the next byte without removing it from the receive buffer.

int	read (void) override
	Read and remove the next byte from the receive buffer.

void	flush () override
	Wait until all queued bytes are transmitted.

size_t	write (uint8_t c) override
	Write one byte.

	operator bool () override
	Check whether the UART is started.

int	availableForWrite (void)
	Get the number of bytes that can be written without blocking.

void	flush (uint32_t timeout)
	Wait until all queued bytes are transmitted, or until a timeout elapses.

size_t	write (unsigned long n)
	Write one byte, truncating the value to 8 bits.

size_t	write (long n)
	Write one byte, truncating the value to 8 bits.

size_t	write (unsigned int n)
	Write one byte, truncating the value to 8 bits.

size_t	write (int n)
	Write one byte, truncating the value to 8 bits.

size_t	write (const uint8_t *buffer, size_t size)
	Write a buffer of bytes.

void	setRx (pin_size_t _rx)
	Set the RX pin by Arduino pin number.

void	setTx (pin_size_t _tx)
	Set the TX pin by Arduino pin number.

void	setRx (PinName _rx)
	Set the RX pin by STM32 pin name.

void	setTx (PinName _tx)
	Set the TX pin by STM32 pin name.

void	setRts (pin_size_t _rts)
	Enable hardware RTS flow control on a digital pin.

void	setCts (pin_size_t _cts)
	Enable hardware CTS flow control on a digital pin.

void	setRtsCts (pin_size_t _rts, pin_size_t _cts)
	Enable hardware RTS and CTS flow control on digital pins.

void	setRts (PinName _rts)
	Enable hardware RTS flow control on an STM32 pin.

void	setCts (PinName _cts)
	Enable hardware CTS flow control on an STM32 pin.

void	setRtsCts (PinName _rts, PinName _cts)
	Enable hardware RTS and CTS flow control on STM32 pins.

void	setHalfDuplex (void)
	Enable half-duplex mode by setting the RX pin to NC.

bool	isHalfDuplex (void) const
	Check whether the UART is in half-duplex mode.

void	enableHalfDuplexRx (void)
	Enable reception in half-duplex mode after the pending transmission ends.

void	setRxInvert (void)
	Invert the RX line in hardware.

void	setTxInvert (void)
	Invert the TX line in hardware.

void	setDataInvert (void)
	Invert the data bits in hardware.

UART_HandleTypeDef *	getHandle (void)
	Get the underlying HAL UART handle.

Static Public Member Functions
static void	_rx_complete_irq (serial_t *obj)
	RX interrupt handler.

static int	_tx_complete_irq (serial_t *obj)
	TX interrupt handler.

Protected Attributes
bool	_written
	Has any byte been written to the UART since begin().

bool	_rx_invert
	Hardware inversion of the RX line, set by setRxInvert().

bool	_tx_invert
	Hardware inversion of the TX line, set by setTxInvert().

bool	_data_invert
	Hardware inversion of the data bits, set by setDataInvert().

unsigned char	_rx_buffer [SERIAL_RX_BUFFER_SIZE]
	Receive ring buffer, filled by _rx_complete_irq() and emptied by read().

unsigned char	_tx_buffer [SERIAL_TX_BUFFER_SIZE]
	Transmit ring buffer, filled by write() and emptied by _tx_complete_irq().

serial_t	_serial
	Low-level serial object: pins, ring buffer indexes and HAL handle.

Friends
class	STM32LowPower

Detailed Description

STM32 hardware UART.

Implements the Arduino Stream and HardwareSerial API.

Use one of the constructors to bind a UART to pins or to a peripheral, then call begin().

Constructor & Destructor Documentation

◆ Uart() [1/5]

Uart::Uart	(	pin_size_t	_rx,
		pin_size_t	_tx,
		pin_size_t	_rts = `NUM_DIGITAL_PINS`,
		pin_size_t	_cts = `NUM_DIGITAL_PINS`
	)

Create a UART from Arduino digital pin numbers.

Parameters

_rx	Digital pin used for RX.
_tx	Digital pin used for TX.
_rts	Digital pin used for RTS flow control, NUM_DIGITAL_PINS if unused.
_cts	Digital pin used for CTS flow control, NUM_DIGITAL_PINS if unused.

◆ Uart() [2/5]

Uart::Uart	(	PinName	_rx,
		PinName	_tx,
		PinName	_rts = `NC`,
		PinName	_cts = `NC`
	)

Create a UART from STM32 pin names.

Parameters

_rx	Pin used for RX.
_tx	Pin used for TX.
_rts	Pin used for RTS flow control, NC if unused.
_cts	Pin used for CTS flow control, NC if unused.

◆ Uart() [3/5]

Uart::Uart	(	void *	peripheral,
		HalfDuplexMode_t	halfDuplex = `HALF_DUPLEX_DISABLED`
	)

Create a UART from an STM32 USART/UART peripheral.

Pins are taken from the variant.

Parameters

peripheral	USART/UART peripheral instance, e.g. USART1.
halfDuplex	HALF_DUPLEX_ENABLED to use the TX pin only.

◆ Uart() [4/5]

Uart::Uart ( pin_size_t _rxtx )

Create a half-duplex UART on a single digital pin.

The pin is used as TX and RX is NC.

Parameters

_rxtx Digital pin used for TX.

◆ Uart() [5/5]

Uart::Uart ( PinName _rxtx )

Create a half-duplex UART on a single STM32 pin.

The pin is used as TX and RX is NC.

Parameters

_rxtx Pin used for TX.

Member Function Documentation

◆ _rx_complete_irq()

void Uart::_rx_complete_irq ( serial_t * obj )

static

RX interrupt handler.

Stores the received byte in the receive buffer.

Note: Called from the UART interrupt context: it must stay short and never block. If the receive buffer is full, the received byte is dropped.

Parameters

obj	UART object that received the byte.

◆ _tx_complete_irq()

int Uart::_tx_complete_irq ( serial_t * obj )

static

TX interrupt handler.

Starts the next chunk of queued data, if any.

Note: Called from the UART interrupt context when a transfer completes: it must stay short and never block. A chunk never wraps around the end of the transmit buffer, so a wrapped buffer is sent in two transfers.

Parameters

obj	UART object whose transfer completed.

Returns: -1 if a new transfer was started, 0 if the transmit buffer is empty.

◆ available()

int Uart::available ( void )

override

Get the number of bytes available to read.

Returns: Number of bytes in the receive buffer.

◆ availableForWrite()

int Uart::availableForWrite ( void )

Get the number of bytes that can be written without blocking.

Returns: Free space in the transmit buffer, in bytes.

◆ begin() [1/2]

void Uart::begin ( unsigned long baud )

inlineoverride

Start the UART with 8 data bits, no parity and 1 stop bit (SERIAL_8N1).

Parameters

baud	Baud rate in bits per second.

◆ begin() [2/2]

void Uart::begin	(	unsigned long	baud,
		uint16_t	config
	)

override

Start the UART with the given baud rate and frame format.

Parameters

baud	Baud rate in bits per second.
config	Frame format, e.g. SERIAL_8N1 or SERIAL_8E1.

◆ flush()

void Uart::flush ( uint32_t timeout )

Wait until all queued bytes are transmitted, or until a timeout elapses.

Parameters

timeout Maximum wait in milliseconds. 0 waits without limit. On timeout, the pending transmit data is discarded.

◆ getHandle()

UART_HandleTypeDef * Uart::getHandle ( void )

inline

Get the underlying HAL UART handle.

Returns: Pointer to the HAL UART handle.

◆ isHalfDuplex()

bool Uart::isHalfDuplex ( void ) const

Check whether the UART is in half-duplex mode.

Returns: true if the RX pin is NC.

◆ operator bool()

Uart::operator bool ( )

inlineoverride

Check whether the UART is started.

Returns: true if begin() was called and the UART is ready.

◆ peek()

int Uart::peek ( void )

override

Read the next byte without removing it from the receive buffer.

Returns: Next byte, or -1 if none is available.

◆ read()

int Uart::read ( void )

override

Read and remove the next byte from the receive buffer.

Returns: Next byte, or -1 if none is available.

◆ setCts() [1/2]

void Uart::setCts ( pin_size_t _cts )

Enable hardware CTS flow control on a digital pin.

Call before begin().

Parameters

_cts	Digital pin used for CTS.

◆ setCts() [2/2]

void Uart::setCts ( PinName _cts )

Enable hardware CTS flow control on an STM32 pin.

Call before begin().

Parameters

_cts	Pin used for CTS.

◆ setDataInvert()

void Uart::setDataInvert ( void )

Invert the data bits in hardware.

Call before begin().

◆ setHalfDuplex()

void Uart::setHalfDuplex ( void )

Enable half-duplex mode by setting the RX pin to NC.

Call before begin().

◆ setRts() [1/2]

void Uart::setRts ( pin_size_t _rts )

Enable hardware RTS flow control on a digital pin.

Call before begin().

Parameters

_rts	Digital pin used for RTS.

◆ setRts() [2/2]

void Uart::setRts ( PinName _rts )

Enable hardware RTS flow control on an STM32 pin.

Call before begin().

Parameters

_rts	Pin used for RTS.

◆ setRtsCts() [1/2]

void Uart::setRtsCts	(	pin_size_t	_rts,
		pin_size_t	_cts
	)

Enable hardware RTS and CTS flow control on digital pins.

Call before begin().

Parameters

_rts	Digital pin used for RTS.
_cts	Digital pin used for CTS.

◆ setRtsCts() [2/2]

void Uart::setRtsCts	(	PinName	_rts,
		PinName	_cts
	)

Enable hardware RTS and CTS flow control on STM32 pins.

Call before begin().

Parameters

_rts	Pin used for RTS.
_cts	Pin used for CTS.

◆ setRx() [1/2]

void Uart::setRx ( pin_size_t _rx )

Set the RX pin by Arduino pin number.

Call before begin().

Parameters

_rx	Digital pin used for RX.

◆ setRx() [2/2]

void Uart::setRx ( PinName _rx )

Set the RX pin by STM32 pin name.

Call before begin().

Parameters

_rx	Pin used for RX.

◆ setRxInvert()

void Uart::setRxInvert ( void )

Invert the RX line in hardware.

Call before begin().

◆ setTx() [1/2]

void Uart::setTx ( pin_size_t _tx )

Set the TX pin by Arduino pin number.

Call before begin().

Parameters

_tx	Digital pin used for TX.

◆ setTx() [2/2]

void Uart::setTx ( PinName _tx )

Set the TX pin by STM32 pin name.

Call before begin().

Parameters

_tx	Pin used for TX.

◆ setTxInvert()

void Uart::setTxInvert ( void )

Invert the TX line in hardware.

Call before begin().

◆ write() [1/6]

size_t Uart::write	(	const uint8_t *	buffer,
		size_t	size
	)

Write a buffer of bytes.

Parameters

buffer	Data to write.
size	Number of bytes in buffer.

Returns: Number of bytes written, 0 if the UART is not started.

◆ write() [2/6]

size_t Uart::write ( int n )

inline

Write one byte, truncating the value to 8 bits.

Parameters

n	Value to write.

Returns: Number of bytes written.

◆ write() [3/6]

size_t Uart::write ( long n )

inline

Write one byte, truncating the value to 8 bits.

Parameters

n	Value to write.

Returns: Number of bytes written.

◆ write() [4/6]

size_t Uart::write ( uint8_t c )

override

Write one byte.

Parameters

c	Byte to write.

Returns: Number of bytes written: 1, or 0 if the UART is not started.

◆ write() [5/6]

size_t Uart::write ( unsigned int n )

inline

Write one byte, truncating the value to 8 bits.

Parameters

n	Value to write.

Returns: Number of bytes written.

◆ write() [6/6]

size_t Uart::write ( unsigned long n )

inline

Write one byte, truncating the value to 8 bits.

Parameters

n	Value to write.

Returns: Number of bytes written.

Member Data Documentation

◆ _data_invert

bool Uart::_data_invert

protected

Hardware inversion of the data bits, set by setDataInvert().

Applied by begin().

◆ _rx_invert

bool Uart::_rx_invert

protected

Hardware inversion of the RX line, set by setRxInvert().

Applied by begin().

◆ _tx_invert

bool Uart::_tx_invert

protected

Hardware inversion of the TX line, set by setTxInvert().

Applied by begin().

◆ _written

bool Uart::_written

protected

Has any byte been written to the UART since begin().

Used by flush() to skip the wait.

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

cores/arduino/Serial.h
cores/arduino/Serial.cpp

Public Member Functions

Static Public Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Uart() [1/5]

◆ Uart() [2/5]

◆ Uart() [3/5]

◆ Uart() [4/5]

◆ Uart() [5/5]

Member Function Documentation

◆ _rx_complete_irq()

◆ _tx_complete_irq()

◆ available()

◆ availableForWrite()

◆ begin() [1/2]

◆ begin() [2/2]

◆ flush()

◆ getHandle()

◆ isHalfDuplex()

◆ operator bool()

◆ peek()

◆ read()

◆ setCts() [1/2]

◆ setCts() [2/2]

◆ setDataInvert()

◆ setHalfDuplex()

◆ setRts() [1/2]

◆ setRts() [2/2]

◆ setRtsCts() [1/2]

◆ setRtsCts() [2/2]

◆ setRx() [1/2]

◆ setRx() [2/2]

◆ setRxInvert()

◆ setTx() [1/2]

◆ setTx() [2/2]

◆ setTxInvert()

◆ write() [1/6]

◆ write() [2/6]

◆ write() [3/6]

◆ write() [4/6]

◆ write() [5/6]

◆ write() [6/6]

Member Data Documentation

◆ _data_invert

◆ _rx_invert

◆ _tx_invert

◆ _written