PWM (Pulse-width modulation) API for Soletta. More...

Data Structures
struct	sol_pwm_config
	PWM configuration struct. More...

Typedefs
typedef struct sol_pwm	sol_pwm
	A handle to a PWM. More...

typedef struct sol_pwm_config	sol_pwm_config
	PWM configuration struct. More...

Enumerations
enum	sol_pwm_alignment { SOL_PWM_ALIGNMENT_LEFT, SOL_PWM_ALIGNMENT_RIGHT, SOL_PWM_ALIGNMENT_CENTER }
	Alignment determines how the pulse is aligned within the PWM period. More...

enum	sol_pwm_polarity { SOL_PWM_POLARITY_NORMAL, SOL_PWM_POLARITY_INVERSED }
	Polarity is whether the output is active-high or active-low. More...

Functions
enum sol_pwm_alignment	sol_pwm_alignment_from_str (const char *pwm_alignment)
	Converts a string PWM alignment to sol_pwm_alignment. More...

const char *	sol_pwm_alignment_to_str (enum sol_pwm_alignment pwm_alignment)
	Converts sol_pwm_alignment to a string name. More...

void	sol_pwm_close (struct sol_pwm *pwm)
	Closes a given PWM pin. More...

int32_t	sol_pwm_get_duty_cycle (const struct sol_pwm *pwm)
	Get PWM duty cycle in nanoseconds. More...

int32_t	sol_pwm_get_period (const struct sol_pwm *pwm)
	Get PWM period in nanoseconds. More...

bool	sol_pwm_is_enabled (const struct sol_pwm *pwm)
	Check wheter a pmw pin is enabled or disabled. More...

struct sol_pwm *	sol_pwm_open (int device, int channel, const struct sol_pwm_config *config)
	Opens a given pin as pwm. More...

struct sol_pwm *	sol_pwm_open_by_label (const char label, const struct sol_pwm_config config)
	Opens a given pin by its board label as pwm. More...

struct sol_pwm *	sol_pwm_open_raw (int device, int channel, const struct sol_pwm_config *config)
	Opens a given pin as pwm. More...

enum sol_pwm_polarity	sol_pwm_polarity_from_str (const char *pwm_polarity)
	Converts a string PWM polarity to sol_pwm_polarity. More...

const char *	sol_pwm_polarity_to_str (enum sol_pwm_polarity pwm_polarity)
	Converts sol_pwm_polarity to a string name. More...

int	sol_pwm_set_duty_cycle (struct sol_pwm *pwm, uint32_t duty_cycle_ns)
	Set PWM duty cycle in nanoseconds. More...

int	sol_pwm_set_enabled (struct sol_pwm *pwm, bool enable)
	Enable or disable a given pwm pin. More...

int	sol_pwm_set_period (struct sol_pwm *pwm, uint32_t period_ns)
	Set PWM period in nanoseconds. More...

Detailed Description

PWM (Pulse-width modulation) API for Soletta.

Typedef Documentation

sol_pwm

A handle to a PWM.

See Also: sol_pwm_open_by_label(); sol_pwm_open(); sol_pwm_open_raw(); sol_pwm_close(); sol_pwm_get_duty_cycle(); sol_pwm_set_duty_cycle(); sol_pwm_get_period(); sol_pwm_set_period(); sol_pwm_is_enabled(); sol_pwm_set_enabled()

typedef struct sol_pwm_config sol_pwm_config

PWM configuration struct.

See Also: sol_pwm_open_by_label(); sol_pwm_open(); sol_pwm_open_raw()

Enumeration Type Documentation

enum sol_pwm_alignment

Alignment determines how the pulse is aligned within the PWM period.

No API for this on Linux (and other OSes), so we simply ignore it there

Enumerator

SOL_PWM_ALIGNMENT_LEFT

The pulse is aligned to the leading-edge (left) of the PWM period.

SOL_PWM_ALIGNMENT_RIGHT

The pulse is aligned to the trailing-edge (right) of the PWM period.

SOL_PWM_ALIGNMENT_CENTER

The pulse is aligned to the center of the PWM period.

Also known as phase-correct.

enum sol_pwm_polarity

Polarity is whether the output is active-high or active-low.

In the paired and complementary configurations, the polarity of the secondary PWM output is determined by the polarity of the primary PWM channel.

This is ignored on RIOT (no API there) and not always supported on Linux.

Enumerator
SOL_PWM_POLARITY_NORMAL
SOL_PWM_POLARITY_INVERSED

Function Documentation

enum sol_pwm_alignment sol_pwm_alignment_from_str ( const char * pwm_alignment )

Converts a string PWM alignment to sol_pwm_alignment.

This function converts a string PWM alignment to enumeration sol_pwm_alignment.

See Also: sol_pwm_alignment_to_str().

Parameters

pwm_alignment Valid values are "left", "center", "right".

Returns: enumeration sol_pwm_alignment

const char* sol_pwm_alignment_to_str ( enum sol_pwm_alignment pwm_alignment )

Converts sol_pwm_alignment to a string name.

This function converts sol_pwm_alignment enumeration to a string PWM alignment.

See Also: sol_pwm_alignment_from_str().

Parameters

pwm_alignment sol_pwm_alignment

Returns: String representation of the sol_pwm_alignment

void sol_pwm_close ( struct sol_pwm * pwm )

Closes a given PWM pin.

See Also: sol_pwm_open(), sol_pwm_open_raw().

Parameters

pwm	The open `sol_pwm` representing the pin to be closed.

int32_t sol_pwm_get_duty_cycle ( const struct sol_pwm * pwm )

Get PWM duty cycle in nanoseconds.

See Also: sol_pwm_set_duty_cycle() for more details.

Parameters

pwm	PWM pin to get property.

Returns: Duty cycle in nanoseconds. It may be a negative value on error.

int32_t sol_pwm_get_period ( const struct sol_pwm * pwm )

Get PWM period in nanoseconds.

See Also: sol_pwm_set_period() for more details.

Parameters

pwm	PWM pin to get property.

Returns: Period in nanoseconds. It may be a negative value on error.

bool sol_pwm_is_enabled ( const struct sol_pwm * pwm )

Check wheter a pmw pin is enabled or disabled.

Parameters

pwm	PWM pin to get property.

Returns: true if enabled or false if disabled or on error.

struct sol_pwm* sol_pwm_open	(	int	device,
		int	channel,
		const struct sol_pwm_config *	config
	)

Opens a given pin as pwm.

A pin (defined by device and channel) should be opened just once, calling this function more than once for the same pin results in undefined behaviour - per platform basis.

See Also: sol_pwm_open_raw(), sol_pwm_close().

The difference between sol_pwm_open_raw() and sol_pwm_open() is that the last will setup pin mux, if enabled.

Parameters

device	The device controlling the pin to be opened.
channel	The channel used to communicate with the pin to be opened.
config	Contains the pin configuration.

Returns: A new sol_pwm instance on success, NULL otherwise.

struct sol_pwm* sol_pwm_open_by_label	(	const char *	label,
		const struct sol_pwm_config *	config
	)

Opens a given pin by its board label as pwm.

This function only works when the board was successfully detected by Soletta and a corresponding pin multiplexer module was found.

A pin should be opened just once, calling this function more than once for the same pin results in undefined behavior - per platform basis.

See Also: sol_pwm_open_raw(), sol_pwm_close().

Parameters

label	The pin to be opened.
config	Contains the pin configuration.

Returns: A new sol_pwm instance on success, NULL otherwise.

struct sol_pwm* sol_pwm_open_raw	(	int	device,
		int	channel,
		const struct sol_pwm_config *	config
	)

Opens a given pin as pwm.

A pin (defined by device and channel) should be opened just once, calling this function more than once for the same pin results in undefined behaviour - per platform basis.

See Also: sol_pwm_open(), sol_pwm_close().

Parameters

device	The device controlling the pin to be opened.
channel	The channel used to communicate with the pin to be opened.
config	Contains the pin configuration.

Returns: A new sol_pwm instance on success, NULL otherwise.

enum sol_pwm_polarity sol_pwm_polarity_from_str ( const char * pwm_polarity )

Converts a string PWM polarity to sol_pwm_polarity.

This function converts a string PWM polarity to enumeration sol_pwm_polarity.

See Also: sol_pwm_polarity_to_str().

Parameters

pwm_polarity Valid values are "normal", "inversed".

Returns: enumeration sol_pwm_polarity

const char* sol_pwm_polarity_to_str ( enum sol_pwm_polarity pwm_polarity )

Converts sol_pwm_polarity to a string name.

This function converts sol_pwm_polarity enumeration to a string PWM polarity.

See Also: sol_pwm_polarity_from_str().

Parameters

pwm_polarity sol_pwm_polarity

Returns: String representation of the sol_pwm_polarity

int sol_pwm_set_duty_cycle	(	struct sol_pwm *	pwm,
		uint32_t	duty_cycle_ns
	)

Set PWM duty cycle in nanoseconds.

Duty cycle describes the proportion of 'on' time to the regular interval or 'period' of time.

A low duty cycle corresponds to low power, because the power is off for most of the time.

Parameters

pwm	PWM pin to be modified.
duty_cycle_ns	Duty cycle in nanoseconds.

Returns: 0 on success or a negative number on error.

int sol_pwm_set_enabled	(	struct sol_pwm *	pwm,
		bool	enable
	)

Enable or disable a given pwm pin.

Parameters

pwm	PWM pin to be modified.
enable	If `true` pwm is enabled and if `false` it's disabled.

Returns: 0 on success or a negative number on error.

int sol_pwm_set_period	(	struct sol_pwm *	pwm,
		uint32_t	period_ns
	)

Set PWM period in nanoseconds.

Period is the amount of time that a cycle (on / off state) takes. It's the inverse of the frequency of the waveform.

Parameters

pwm	PWM pin to be modified.
period_ns	Period in nanoseconds.

Returns: 0 on success or a negative number on error.

Data Structures

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

Enumeration Type Documentation

Function Documentation