Pulse Width Modulation (PWM) peripheral driver. More...

Topics
	PWM peripheral driver configuration

Data Structures
struct	nrfx_pwm_config_t
	PWM driver configuration structure. More...

struct	nrfx_pwm_t
	PWM driver instance data structure. More...

Macros
#define	NRFX_PWM_DEFAULT_CONFIG(_out_0, _out_1, _out_2, _out_3)
	PWM driver default configuration.

#define	NRFX_PWM_INSTANCE(reg)
	Macro for creating a PWM driver instance.

Typedefs
typedef void(*	nrfx_pwm_event_handler_t) (nrfx_pwm_event_type_t event_type, void *p_context)
	PWM event handler type for user-defined callback function.

Enumerations
enum	nrfx_pwm_flag_t { NRFX_PWM_FLAG_STOP = 0x01 , NRFX_PWM_FLAG_LOOP = 0x02 , NRFX_PWM_FLAG_SIGNAL_END_SEQ0 = 0x04 , NRFX_PWM_FLAG_SIGNAL_END_SEQ1 = 0x08 , NRFX_PWM_FLAG_NO_EVT_FINISHED = 0x10 , NRFX_PWM_FLAG_START_VIA_TASK = 0x80 }
	PWM flags providing additional playback options. More...

enum	nrfx_pwm_event_type_t { NRFX_PWM_EVENT_FINISHED , NRFX_PWM_EVENT_END_SEQ0 , NRFX_PWM_EVENT_END_SEQ1 , NRFX_PWM_EVENT_STOPPED }
	PWM driver event type. More...

Functions
int	nrfx_pwm_init (nrfx_pwm_t p_instance, nrfx_pwm_config_t const p_config, nrfx_pwm_event_handler_t handler, void *p_context)
	Function for initializing the PWM driver.

int	nrfx_pwm_reconfigure (nrfx_pwm_t const p_instance, nrfx_pwm_config_t const p_config)
	Function for reconfiguring the PWM driver.

void	nrfx_pwm_uninit (nrfx_pwm_t *p_instance)
	Function for uninitializing the PWM driver.

bool	nrfx_pwm_init_check (nrfx_pwm_t const *p_instance)
	Function for checking if the PWM driver instance is initialized.

uint32_t	nrfx_pwm_simple_playback (nrfx_pwm_t p_instance, nrf_pwm_sequence_t const p_sequence, uint16_t playback_count, uint32_t flags)
	Function for starting a single sequence playback.

uint32_t	nrfx_pwm_complex_playback (nrfx_pwm_t p_instance, nrf_pwm_sequence_t const p_sequence_0, nrf_pwm_sequence_t const *p_sequence_1, uint16_t playback_count, uint32_t flags)
	Function for starting a two-sequence playback.

NRFX_STATIC_INLINE void	nrfx_pwm_step (nrfx_pwm_t const *p_instance)
	Function for advancing the active sequence.

bool	nrfx_pwm_stop (nrfx_pwm_t *p_instance, bool wait_until_stopped)
	Function for stopping the sequence playback.

bool	nrfx_pwm_stopped_check (nrfx_pwm_t *p_instance)
	Function for checking the status of the PWM peripheral.

void	nrfx_pwm_irq_handler (nrfx_pwm_t *p_instance)
	Driver interrupt handler.

NRFX_STATIC_INLINE void	nrfx_pwm_sequence_update (nrfx_pwm_t const p_instance, uint8_t seq_id, nrf_pwm_sequence_t const p_sequence)
	Function for updating the sequence data during playback.

NRFX_STATIC_INLINE uint32_t	nrfx_pwm_task_address_get (nrfx_pwm_t const *p_instance, nrf_pwm_task_t task)
	Function for returning the address of a specified PWM task that can be used in PPI module.

NRFX_STATIC_INLINE uint32_t	nrfx_pwm_event_address_get (nrfx_pwm_t const *p_instance, nrf_pwm_event_t event)
	Function for returning the address of a specified PWM event that can be used in PPI module.

Detailed Description

Pulse Width Modulation (PWM) peripheral driver.

Macro Definition Documentation

◆ NRFX_PWM_DEFAULT_CONFIG

#define NRFX_PWM_DEFAULT_CONFIG	(	_out_0,
		_out_1,
		_out_2,
		_out_3 )

Value:

{                                                               \
    .output_pins   = {                                          \
        _out_0,                                                 \
        _out_1,                                                 \
        _out_2,                                                 \
        _out_3,                                                 \
    },                                                          \
    .pin_inverted  = {                                          \
        false,                                                  \
        false,                                                  \
        false,                                                  \
        false,                                                  \
    },                                                          \
    .irq_priority  = NRFX_PWM_DEFAULT_CONFIG_IRQ_PRIORITY,      \
    .base_clock    = NRF_PWM_CLK_1MHz,                          \
    .count_mode    = NRF_PWM_MODE_UP,                           \
    .top_value     = 1000,                                      \
    .load_mode     = NRF_PWM_LOAD_COMMON,                       \
    .step_mode     = NRF_PWM_STEP_AUTO,                         \
    .skip_gpio_cfg = false                                      \
}

PWM driver default configuration.

This configuration sets up PWM with the following options:

clock frequency: 1 MHz
count up
top value: 1000 clock ticks
load mode: common
step mode: auto

Parameters

[in]	_out_0	PWM output 0 pin.
[in]	_out_1	PWM output 1 pin.
[in]	_out_2	PWM output 2 pin.
[in]	_out_3	PWM output 3 pin.

◆ NRFX_PWM_INSTANCE

#define NRFX_PWM_INSTANCE ( reg )

Value:

{                                 \
    .p_reg = (NRF_PWM_Type *)reg, \
    .cb    = {0},                 \
}

Macro for creating a PWM driver instance.

Enumeration Type Documentation

◆ nrfx_pwm_event_type_t

enum nrfx_pwm_event_type_t

PWM driver event type.

Enumerator
NRFX_PWM_EVENT_FINISHED	Sequence playback finished.
NRFX_PWM_EVENT_END_SEQ0	End of sequence 0 reached. Its data can be safely modified now.
NRFX_PWM_EVENT_END_SEQ1	End of sequence 1 reached. Its data can be safely modified now.
NRFX_PWM_EVENT_STOPPED	The PWM peripheral has been stopped.

◆ nrfx_pwm_flag_t

enum nrfx_pwm_flag_t

PWM flags providing additional playback options.

Enumerator
NRFX_PWM_FLAG_STOP	When the requested playback is finished, the peripheral will be stopped. Note The STOP task is triggered when the last value of the final sequence is loaded from RAM, and the peripheral stops at the end of the current PWM period. For sequences with configured repeating of duty cycle values, this might result in less than the requested number of repeats of the last value.
NRFX_PWM_FLAG_LOOP	When the requested playback is finished, it will be started from the beginning. This flag is ignored if used together with NRFX_PWM_FLAG_STOP. Note The playback restart is done via a shortcut configured in the PWM peripheral. This shortcut triggers the proper starting task when the final value of previous playback is read from RAM and applied to the pulse generator counter. When this mechanism is used together with the NRF_PWM_STEP_TRIGGERED mode, the playback restart will occur right after switching to the final value (this final value will be played only once).
NRFX_PWM_FLAG_SIGNAL_END_SEQ0	The event handler is to be called when the last value from sequence 0 is loaded.
NRFX_PWM_FLAG_SIGNAL_END_SEQ1	The event handler is to be called when the last value from sequence 1 is loaded.
NRFX_PWM_FLAG_NO_EVT_FINISHED	The playback finished event (enabled by default) is to be suppressed.
NRFX_PWM_FLAG_START_VIA_TASK	The playback must not be started directly by the called function. Instead, the function must only prepare it and return the address of the task to be triggered to start the playback.

Function Documentation

◆ nrfx_pwm_complex_playback()

uint32_t nrfx_pwm_complex_playback	(	nrfx_pwm_t *	p_instance,
		nrf_pwm_sequence_t const *	p_sequence_0,
		nrf_pwm_sequence_t const *	p_sequence_1,
		uint16_t	playback_count,
		uint32_t	flags )

Function for starting a two-sequence playback.

Use the NRFX_PWM_FLAG_START_VIA_TASK flag if you want the playback to be only prepared by this function, and you want to start it later by triggering a task (using PPI for instance). The function will then return the address of the task to be triggered.

Note: The array containing the duty cycle values for the specified sequence must be in RAM and cannot be allocated on the stack. For detailed information, see nrf_pwm_sequence_t.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_sequence_0	First sequence to be played back.
[in]	p_sequence_1	Second sequence to be played back.
[in]	playback_count	Number of playbacks to be performed (must not be 0).
[in]	flags	Additional options. Pass any combination of playback flags, or 0 for default settings.

Returns: Address of the task to be triggered to start the playback if the NRFX_PWM_FLAG_START_VIA_TASK flag was used, 0 otherwise.

◆ nrfx_pwm_event_address_get()

NRFX_STATIC_INLINE uint32_t nrfx_pwm_event_address_get	(	nrfx_pwm_t const *	p_instance,
		nrf_pwm_event_t	event )

Function for returning the address of a specified PWM event that can be used in PPI module.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	event	Requested event.

Returns: Event address.

◆ nrfx_pwm_init()

int nrfx_pwm_init	(	nrfx_pwm_t *	p_instance,
		nrfx_pwm_config_t const *	p_config,
		nrfx_pwm_event_handler_t	handler,
		void *	p_context )

Function for initializing the PWM driver.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_config	Pointer to the structure with the initial configuration. NULL if configuration is to be skipped and will be done later using nrfx_pwm_reconfigure.
[in]	handler	Event handler provided by the user. If NULL is passed instead, event notifications are not done and PWM interrupts are disabled.
[in]	p_context	Context passed to the event handler.

Return values

0	Initialization was successful.
-EALREADY	The driver is already initialized.

◆ nrfx_pwm_init_check()

bool nrfx_pwm_init_check ( nrfx_pwm_t const * p_instance )

Function for checking if the PWM driver instance is initialized.

Parameters

[in] p_instance Pointer to the driver instance structure.

Return values

true	Instance is already initialized.
false	Instance is not initialized.

◆ nrfx_pwm_irq_handler()

void nrfx_pwm_irq_handler ( nrfx_pwm_t * p_instance )

Driver interrupt handler.

Parameters

[in] p_instance Pointer to the driver instance structure.

◆ nrfx_pwm_reconfigure()

int nrfx_pwm_reconfigure	(	nrfx_pwm_t const *	p_instance,
		nrfx_pwm_config_t const *	p_config )

Function for reconfiguring the PWM driver.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_config	Pointer to the structure with the configuration.

Return values

0	Reconfiguration was successful.
-EBUSY	The driver is during playback.
-EINPROGRESS	The driver is uninitialized.

◆ nrfx_pwm_sequence_update()

NRFX_STATIC_INLINE void nrfx_pwm_sequence_update	(	nrfx_pwm_t const *	p_instance,
		uint8_t	seq_id,
		nrf_pwm_sequence_t const *	p_sequence )

Function for updating the sequence data during playback.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	seq_id	Identifier of the sequence (0 or 1).
[in]	p_sequence	Pointer to the new sequence definition.

◆ nrfx_pwm_simple_playback()

uint32_t nrfx_pwm_simple_playback	(	nrfx_pwm_t *	p_instance,
		nrf_pwm_sequence_t const *	p_sequence,
		uint16_t	playback_count,
		uint32_t	flags )

Function for starting a single sequence playback.

To take advantage of the looping mechanism in the PWM peripheral, both sequences must be used (single sequence can be played back only once by the peripheral). Therefore, the provided sequence is internally set and played back as both sequence 0 and sequence 1. Consequently, if the end of sequence notifications are required, events for both sequences must be used (that is, both the NRFX_PWM_FLAG_SIGNAL_END_SEQ0 flag and the NRFX_PWM_FLAG_SIGNAL_END_SEQ1 flag must be specified, and the NRFX_PWM_EVENT_END_SEQ0 event and the NRFX_PWM_EVENT_END_SEQ1 event must be handled in the same way).

Use the NRFX_PWM_FLAG_START_VIA_TASK flag if you want the playback to be only prepared by this function, and you want to start it later by triggering a task (for example, by using PPI). The function will then return the address of the task to be triggered.

Note: The array containing the duty cycle values for the specified sequence must be in RAM and cannot be allocated on the stack. For detailed information, see nrf_pwm_sequence_t.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	p_sequence	Sequence to be played back.
[in]	playback_count	Number of playbacks to be performed (must not be 0).
[in]	flags	Additional options. Pass any combination of playback flags, or 0 for default settings.

Returns: Address of the task to be triggered to start the playback if the NRFX_PWM_FLAG_START_VIA_TASK flag was used, 0 otherwise.

◆ nrfx_pwm_step()

NRFX_STATIC_INLINE void nrfx_pwm_step ( nrfx_pwm_t const * p_instance )

Function for advancing the active sequence.

This function only applies to NRF_PWM_STEP_TRIGGERED mode.

Parameters

[in] p_instance Pointer to the driver instance structure.

◆ nrfx_pwm_stop()

bool nrfx_pwm_stop	(	nrfx_pwm_t *	p_instance,
		bool	wait_until_stopped )

Function for stopping the sequence playback.

The playback is stopped at the end of the current PWM period. This means that if the active sequence is configured to repeat each duty cycle value for a certain number of PWM periods, the last played value might appear on the output less times than requested.

Note: This function can be instructed to wait until the playback is stopped (by setting wait_until_stopped to true). Depending on the length of the PMW period, this might take a significant amount of time. Alternatively, the nrfx_pwm_stopped_check function can be used to poll the status, or the NRFX_PWM_EVENT_STOPPED event can be used to get the notification when the playback is stopped, provided the event handler is defined.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	wait_until_stopped	If true, the function will not return until the playback is stopped.

Return values

true	The PWM peripheral is stopped.
false	The PWM peripheral is not stopped.

◆ nrfx_pwm_stopped_check()

bool nrfx_pwm_stopped_check ( nrfx_pwm_t * p_instance )

Function for checking the status of the PWM peripheral.

Parameters

[in] p_instance Pointer to the driver instance structure.

Return values

true	The PWM peripheral is stopped.
false	The PWM peripheral is not stopped.

◆ nrfx_pwm_task_address_get()

NRFX_STATIC_INLINE uint32_t nrfx_pwm_task_address_get	(	nrfx_pwm_t const *	p_instance,
		nrf_pwm_task_t	task )

Function for returning the address of a specified PWM task that can be used in PPI module.

Parameters

[in]	p_instance	Pointer to the driver instance structure.
[in]	task	Requested task.

Returns: Task address.

◆ nrfx_pwm_uninit()

void nrfx_pwm_uninit ( nrfx_pwm_t * p_instance )

Function for uninitializing the PWM driver.

If any sequence playback is in progress, it is stopped immediately.

Parameters

[in] p_instance Pointer to the driver instance structure.

Topics

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ NRFX_PWM_DEFAULT_CONFIG

◆ NRFX_PWM_INSTANCE

Enumeration Type Documentation

◆ nrfx_pwm_event_type_t

◆ nrfx_pwm_flag_t

Function Documentation

◆ nrfx_pwm_complex_playback()

◆ nrfx_pwm_event_address_get()

◆ nrfx_pwm_init()

◆ nrfx_pwm_init_check()

◆ nrfx_pwm_irq_handler()

◆ nrfx_pwm_reconfigure()

◆ nrfx_pwm_sequence_update()

◆ nrfx_pwm_simple_playback()

◆ nrfx_pwm_step()

◆ nrfx_pwm_stop()

◆ nrfx_pwm_stopped_check()

◆ nrfx_pwm_task_address_get()

◆ nrfx_pwm_uninit()