Abstraction around the Semtex SX1509B Level-Shifting GPIO Extender. More...

#include <nrfcxx/misc/sx1509b.hpp>

Data Structures
struct	gpio_regs_type
	Structure for SX1509 registers that are controlled. More...

struct	iface_config_type
	The pieces you need to talk to the device. More...

struct	led_pwm_type
	Extended configuration for fade-capable pins. More...

struct	led_type
	Basic structure for LED configuration. More...

Public Member Functions
const iface_config_type &	iface_config () const
	Access the interface configuration for the device.

const gpio_regs_type &	gpio_cache () const noexcept
	Access the internal cache of GPIO registers.

uint16_t	led_driver_cache () const
	Access the internal cache of LEDDriverEnable.

uint8_t	clock_cache () const
	Access the internal cache of Clock.

uint8_t	misc_cache () const
	Access the internal cache of Misc.

int	reload_cache () noexcept
	Read all locally cached registers from the device. More...

unsigned int	configuration (unsigned int psel) const noexcept
	Return the GPIO pin configuration for the given IOX pin. More...

int	configure (unsigned int psel, unsigned int pin_cnf, int initial=-1) noexcept
	Change the GPIO pin configuration for the given IOX pin. More...

int	multiconfigure (uint16_t out_set, uint16_t out_clear, uint16_t pull_down, uint16_t pull_up=0) noexcept
	Configure multiple pins at once. More...

	sx1509b (iface_config_type &ifc, unsigned int addr=0) noexcept
	Instantiate the device. More...

int	hw_reset () noexcept
	Reset the device to its power-on state via RESETn. More...

int	sw_reset () noexcept
	Reset the device to its power-on state via software command. More...

int	clock () const noexcept
	Read the Clock register from the SX1509B. More...

int	clock (uint8_t value) noexcept
	Set the Clock register in the SX1509B. More...

int	misc () const noexcept
	Read the Misc register from the SX1509B. More...

int	misc (uint8_t value) noexcept
	Set the Misc register in the SX1509B. More...

int	configure_as_leds (uint16_t leds, bool source_current=false) noexcept
	Configure a set of pins for LED operations. More...

int	led_configuration (unsigned int psel, led_type &cfg) const noexcept
	Read the LED configuration for the given pin. More...

int	led_configuration (unsigned int psel, led_pwm_type &cfg) const noexcept
	Set the LED configuration for the given pin. More...

int	led_configure (unsigned int psel, const led_type &cfg) const noexcept
	Set the LED configuration for the given pin. More...

int	led_configure (unsigned int psel, const led_pwm_type &cfg) const noexcept
	Set the LED configuration for the given pin. More...

int	output_sct (uint16_t set, uint16_t clear) noexcept
	Multi-signal set, clear, and toggle API. More...

Static Public Attributes
static constexpr auto	RegClock_FREQ_Pos = 5U

static constexpr uint16_t	RegClock_FREQ_Msk = 0x03 << RegClock_FREQ_Pos

static constexpr uint16_t	RegClock_FREQ_Off = 0

static constexpr uint16_t	RegClock_FREQ_External = 1

static constexpr uint16_t	RegClock_FREQ_2MHz = 2

static constexpr auto	RegClock_OSCIO_Pos = 4U

static constexpr uint16_t	RegClock_OSCIO_Msk = 0x01 << RegClock_OSCIO_Pos

static constexpr uint16_t	RegClock_OSCIO_Input = 0

static constexpr uint16_t	RegClock_OSCIO_Output = 1

static constexpr auto	RegClock_OUTFREQ_Pos = 0U

static constexpr uint16_t	RegClock_OUTFREQ_Msk = 0x0F << RegClock_OUTFREQ_Pos

static constexpr uint16_t	RegClock_OUTFREQ_Low = 0

static constexpr uint16_t	RegClock_OUTFREQ_High = 0x0F

static constexpr auto	RegMisc_LEDB_Pos = 7U

static constexpr uint16_t	RegMisc_LEDB_Msk = 1U << RegMisc_LEDB_Pos

static constexpr uint16_t	RegMisc_LEDB_Linear = 0

static constexpr uint16_t	RegMisc_LEDB_Logarithmic = 1

static constexpr auto	RegMisc_LEDFREQ_Pos = 4U

static constexpr uint16_t	RegMisc_LEDFREQ_Msk = 0x07U << RegMisc_LEDFREQ_Pos

static constexpr uint16_t	RegMisc_LEDFREQ_Off = 0

static constexpr auto	RegMisc_LEDA_Pos = 3U

static constexpr uint16_t	RegMisc_LEDA_Msk = 1U << RegMisc_LEDA_Pos

static constexpr uint16_t	RegMisc_LEDA_Linear = 0

static constexpr uint16_t	RegMisc_LEDA_Logarithmic = 1

static constexpr auto	RegMisc_NRESET_Pos = 2U

static constexpr uint16_t	RegMisc_NRESET_Msk = 1U << RegMisc_NRESET_Pos

static constexpr uint16_t	RegMisc_NRESET_POR = 0

static constexpr uint16_t	RegMisc_NRESET_ResetCounters = 1

static constexpr auto	RegMisc_AUTOINC_Pos = 1U

static constexpr uint16_t	RegMisc_AUTOINC_Msk = 1U << RegMisc_AUTOINC_Pos

static constexpr uint16_t	RegMisc_AUTOINC_On = 0

static constexpr uint16_t	RegMisc_AUTOINC_Off = 1

static constexpr auto	RegMisc_AUTOCLR_Pos = 0U

static constexpr uint16_t	RegMisc_AUTOCLR_Msk = 1U << RegMisc_AUTOCLR_Pos

static constexpr uint16_t	RegMisc_AUTOCLR_On = 0

static constexpr uint16_t	RegMisc_AUTOCLR_Off = 1

static constexpr auto	RegTOnX_TOn_Pos = 0U

static constexpr uint16_t	RegTOnX_TOn_Msk = 0x1F << RegTOnX_TOn_Pos

static constexpr auto	RegOffX_TOff_Pos = 3U

static constexpr uint16_t	RegOffX_TOff_Msk = 0x1F << RegOffX_TOff_Pos

static constexpr auto	RegOffX_IOff_Pos = 0U

static constexpr uint16_t	RegOffX_IOff_Msk = 0x07 << RegOffX_IOff_Pos

Detailed Description

Abstraction around the Semtex SX1509B Level-Shifting GPIO Extender.

Note: At this time only basic GPIO and LED driver functionality is supported.

See also: https://www.semtech.com/products/smart-sensing/io-expanders/sx1509b

Constructor & Destructor Documentation

◆ sx1509b()

nrfcxx::misc::sx1509b::sx1509b	(	iface_config_type &	ifc,
		unsigned int	addr = `0`
	)

noexcept

Instantiate the device.

Parameters

ifc	reference to an externally owned struct providing the resources required to communicate with the device.
addr	the device address as controlled by the A0 and A1 pins, value in the range 0 to 3.

Member Function Documentation

◆ clock() [1/2]

int nrfcxx::misc::sx1509b::clock ( ) const

noexcept

Read the Clock register from the SX1509B.

Note: The cached value will not be updated.

◆ clock() [2/2]

int nrfcxx::misc::sx1509b::clock ( uint8_t value )

noexcept

Set the Clock register in the SX1509B.

On success the cached value will also be updated.

◆ configuration()

unsigned int nrfcxx::misc::sx1509b::configuration ( unsigned int psel ) const

noexcept

Return the GPIO pin configuration for the given IOX pin.

The value is compatible with Nordic GPIOs, and is derived from the internal cache of the SX1509B register set.

Parameters

psel	the IOX pin index, in the range 0..15.

Returns: the Nordig GPIO pin configuration inferred from the SX1509B register cache.

◆ configure()

int nrfcxx::misc::sx1509b::configure	(	unsigned int	psel,
		unsigned int	pin_cnf,
		int	initial = `-1`
	)

noexcept

Change the GPIO pin configuration for the given IOX pin.

This translates the standard Nordic GPIO pin flags into SX1509B register mutations through this process:

If the pin had been configured via configure_as_leds() its LEDDriverEnable bit will be cleared;
If an initial value is provided, the corresponding bit in Data will be updated if necessary;
INPUT controls InputDisable;
DIR controls Dir;
PULL controls PullUp and PullDown;
SENSE is not used;
DRIVE is not used;
OpenDrain is cleared

Parameters

psel	the IOX pin index, in the range 0..15.
pin_cnf	the Nordic GPIO pin configuration to emulate.
initial	if zero ensure the Data bit is cleared before configuration; if positive ensure the Data is set before configuration; if negative the Data register is not affected by configuration.

Returns: a non-negative value on success, or a negative error code.

◆ configure_as_leds()

int nrfcxx::misc::sx1509b::configure_as_leds	(	uint16_t	leds,
		bool	source_current = `false`
	)

noexcept

Configure a set of pins for LED operations.

Parameters

leds	bit mask identifying pins that should be enabled the LED driver.
source_current	if `true` the SX1509B will be configured to drive the LED pins as normal outputs. If `false` OpenDrain will be enabled for the LED pins.

Returns: a non-negative value on success, or a negative error code.

◆ hw_reset()

int nrfcxx::misc::sx1509b::hw_reset ( )

noexcept

Reset the device to its power-on state via RESETn.

This works as long as misc() is not configured to use the RESETn signal to synchronize PWM counters.

Returns: a non-negative duration in ms to wait until the device will have completed reset, or a negative error code.

◆ led_configuration() [1/2]

int nrfcxx::misc::sx1509b::led_configuration	(	unsigned int	psel,
		led_pwm_type &	cfg
	)		const

noexcept

Set the LED configuration for the given pin.

Parameters

psel	the IOX pin index. The pin need not be configured for LED use.
cfg	where to store the fade-capable configuration to use. If the pin does not support fade the call will return an error.

Returns: a non-negative value on success, or a negative error code.

◆ led_configuration() [2/2]

int nrfcxx::misc::sx1509b::led_configuration	(	unsigned int	psel,
		led_type &	cfg
	)		const

noexcept

Read the LED configuration for the given pin.

Parameters

psel	the IOX pin index. The pin need not be configured for LED use.
cfg	where to store the non-fade configuration to use.

Returns: a non-negative value on success, or a negative error code.

◆ led_configure() [1/2]

int nrfcxx::misc::sx1509b::led_configure	(	unsigned int	psel,
		const led_pwm_type &	cfg
	)		const

noexcept

Set the LED configuration for the given pin.

Parameters

psel	the IOX pin index. The pin need not be configured for LED use.
cfg	the fade configuration to use. If the pin does not support fade the call will return an error.

Returns: a non-negative value on success, or a negative error code.

◆ led_configure() [2/2]

int nrfcxx::misc::sx1509b::led_configure	(	unsigned int	psel,
		const led_type &	cfg
	)		const

noexcept

Set the LED configuration for the given pin.

Note: If this is used to configure a LED that supports fade the rise and fall times will not be affected.

Parameters

psel	the IOX pin index. The pin need not be configured for LED use.
cfg	the non-fade configuration to use.

Returns: a non-negative value on success, or a negative error code.

◆ misc() [1/2]

int nrfcxx::misc::sx1509b::misc ( ) const

noexcept

Read the Misc register from the SX1509B.

Note: The cached value will not be updated.

◆ misc() [2/2]

int nrfcxx::misc::sx1509b::misc ( uint8_t value )

noexcept

Set the Misc register in the SX1509B.

On success the cached value will also be updated.

◆ multiconfigure()

int nrfcxx::misc::sx1509b::multiconfigure	(	uint16_t	out_set,
		uint16_t	out_clear,
		uint16_t	pull_down,
		uint16_t	pull_up = `0`
	)

noexcept

Configure multiple pins at once.

Pins where the corresponding bit is not set in out_set or out_clear are configured as inputs.

Note: This function is intended to be used immediately after reset. The only registers configured are: PullUp, PullDown, Dir, Data.

Parameters

out_set	bits identifying pins that are to be configured as output, normal drive, initially set.
out_clear	bits identifying pins that are to be configured as output, normal drive, initially clear. Any bit set here and in `out_set` will be treated as if only in `out_set`.
pull_down	bits identifying pins that are to be configured as pull-down. Both input and output pins will be configured.
pull_up	bits identifying pins that are to be configured as pull-up. Both input and output pins will be configured. Any bit set here and in `pull_down` will be treated as if only in `pull_down`.

Returns: non-negative on success, or a negative error code.

◆ output_sct()

int nrfcxx::misc::sx1509b::output_sct	(	uint16_t	set,
		uint16_t	clear
	)

noexcept

Multi-signal set, clear, and toggle API.

If a bit is set in both set and clear its current value is toggled. If no bits are set in set or clear the current IOX output configuration is returned from cache.

Parameters

set	bits identifying IOX outputs that should be high.
clear	bits identifying IOX outputs that should be low.

Returns: a non-negative value provides the current setting for all IOX outputs. A negative value indicates a failure to configure the outputs.

◆ reload_cache()

int nrfcxx::misc::sx1509b::reload_cache ( )

noexcept

Read all locally cached registers from the device.

This may be used if you believe gpio_cache() or other local storage is not accurate.

Warning: Be aware that the gpio_regs_type::data carries the input signal, not the output setting, if gpio_regs_type::input_disable is clear. This may result in confusing values if the signal connected to the pin is pulled in the opposite direction.

Returns: non-negative on success, or a negative error code.

◆ sw_reset()

int nrfcxx::misc::sx1509b::sw_reset ( )

noexcept

Reset the device to its power-on state via software command.

Returns: a non-negative duration in ms to wait until the device will have completed reset, or a negative error code.

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

nrfcxx/misc/sx1509b.hpp

Data Structures

Public Member Functions

Static Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ sx1509b()

Member Function Documentation

◆ clock() [1/2]

◆ clock() [2/2]

◆ configuration()

◆ configure()

◆ configure_as_leds()

◆ hw_reset()

◆ led_configuration() [1/2]

◆ led_configuration() [2/2]

◆ led_configure() [1/2]

◆ led_configure() [2/2]

◆ misc() [1/2]

◆ misc() [2/2]

◆ multiconfigure()

◆ output_sct()

◆ reload_cache()

◆ sw_reset()