nrfcxx::periph::UART Class Reference

Wrapper around the nRF51 UART peripheral. More...

#include <nrfcxx/periph.hpp>

Data Structures
struct	statistics_type
	Statistics on the UART operation. More...

Public Types
using	fifo_type = pabigot::container::rr_adaptor< uint8_t >
	The type used for transmission and reception buffers.
using	size_type = unsigned int
	The type used for transfer sizes (unsigned)
using	ssize_type = int
	The type used for transfer sizes or errors (signed)

Public Member Functions
void	enable (uint32_t cfg_baudrate=UART_BAUDRATE_BAUDRATE_Baud115200, bool hwfc=false)
	Enable the UART. More...
void	disable ()
	Disable the UART.
bool	enabled (bool live=false) const
	Indicate whether UART is enabled. More...
bool	autoenable (int on)
	Query or control whether the UART self-enables for output. More...
ssize_type	write (const uint8_t *sp, size_type count)
	Write data to the UART. More...
ssize_type	read (uint8_t *dp, size_type count)
	Read data from the UART. More...
statistics_type	statistics () const
	Get a snapshot of the UART statistics.
event_set &	events ()
	Reference the UART events. More...
void	irq_handler ()
	Implementation for UART#_IRQHandler required by this module. More...
const nrf5::UART_Type &	peripheral () const
	Reference the nRF5 UART peripheral instance used by the abstraction.

Static Public Member Functions
static UART &	instance ()
	Reference the abstraction instance for UART0.

Static Public Attributes
static constexpr event_set::event_type	EVT_RXAVAIL = 0x01
	Event set in events() when data is received.
static constexpr event_set::event_type	EVT_TXAVAIL = 0x02
	Event set in events() when there is space in the transmit buffer.
static constexpr event_set::event_type	EVT_TXDONE = 0x04
	Event set in events() when transmission completes. More...
static constexpr event_set::event_type	EVT_ERROR = 0x04
	Event set in events() when an error is detected. More...
static UART	UART0
	A reference to a board-specific standard UART instance.

Protected Member Functions
	UART (const nrf5::UART_Type &uart, fifo_type &rxb, fifo_type &txb, int rxd_pin, int txd_pin, int cts_pin=-1, int rts_pin=-1)

Detailed Description

Wrapper around the nRF51 UART peripheral.

This provides interrupt-driven (only) transmission and reception.

Note

This module does not configure the RTS and CTS GPIOs. If hardware flow control is enabled RTS should be configured through GPIO logic high to notify connected devices that there is no listener during periods when the UART is disabled. When the UART is enabled RTS will be controlled by it, based on whether there is space in the peripheral receive buffer.

Member Function Documentation

autoenable()

bool nrfcxx::periph::UART::autoenable

(

int

on

)

Query or control whether the UART self-enables for output.

By default the UART is entirely controlled by enable(). If auto-enable is requested the UART will be disabled internally except when there is material pending transmission.

An explicit use invocation of enable() or disable() turns off auto-enable.

Parameters

on	positive to turn on auto-enable; zero to turn off auto-enable; negative to return the current state without changing it.

Returns

true if auto-enable is turned on, otherwise false.

enable()

void nrfcxx::periph::UART::enable	(	uint32_t	cfg_baudrate = UART_BAUDRATE_BAUDRATE_Baud115200,
		bool	hwfc = false
	)

Enable the UART.

Note

Use of autoenable() may cause the device to be disabled during periods when there is no transmission pending.

Parameters

cfg_baudrate	the NRF51 BAUDRATE.BAUDRATE field value from the Nordic headers. Note that the value is not numerically equivalent to the baud rate. An explicit zero value selects the default baud rate.
hwfc	true iff hardware flow control should be enabled. The value is ignored if either RTS or CTS pins are undefined.

enabled()

bool nrfcxx::periph::UART::enabled

(

bool

live = false

)

const

Indicate whether UART is enabled.

Parameters

live	if true this returns the actual state of the peripheral. If false this disregards a disable due to autoenable().

events()

event_set& nrfcxx::periph::UART::events

(

)

Reference the UART events.

See also

EVT_RXAVAIL

EVT_TXAVAIL

EVT_TXDONE

EVT_ERROR

irq_handler()

void nrfcxx::periph::UART::irq_handler

(

)

Implementation for UART#_IRQHandler required by this module.

This class requires that the UART#_IRQHandler process events to fulfill its obligations. At this time the handler is implicitly installed for UART0.

read()

ssize_type nrfcxx::periph::UART::read	(	uint8_t *	dp,
		size_type	count
	)

Read data from the UART.

Parameters

dp	pointer to where received octets should be written
count	the maximum number of octets to be read

Returns

the number of octets actually read. This may be less than count if the receive buffer does not have the requested amount of data.

write()

ssize_type nrfcxx::periph::UART::write	(	const uint8_t *	sp,
		size_type	count
	)

Write data to the UART.

Parameters

sp	pointer to the source of the data
count	the number of octets to be written

Returns

the number of octets actually written. This may be less than count if the transmit buffer lacks space.

Field Documentation

EVT_ERROR

constexpr event_set::event_type nrfcxx::periph::UART::EVT_ERROR = 0x04

staticconstexpr

Event set in events() when an error is detected.

Specifically a hardware error; dropped received data is not detected through this event.

EVT_TXDONE

constexpr event_set::event_type nrfcxx::periph::UART::EVT_TXDONE = 0x04

staticconstexpr

Event set in events() when transmission completes.

This event does not occur when the transmit buffer is emptied, but only when it remains empty after the UART has transmitted the last byte.

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

• nrfcxx/periph.hpp