Struct rppal::pwm::Pwm

pub struct Pwm { /* private fields */ }

Provides access to the Raspberry Pi’s PWM peripheral.

Before using Pwm, make sure the selected PWM channel has been configured and activated. More information can be found here.

The embedded-hal trait implementations for Pwm can be enabled by specifying the optional hal feature in the dependency declaration for the rppal crate.

Implementations

impl Pwm

pub fn new(channel: Channel) -> Result<Pwm>

Constructs a new Pwm.

new doesn’t change the channel’s period, pulse width or polarity. The channel will remain disabled until enable is called.

pub fn with_period( channel: Channel, period: Duration, pulse_width: Duration, polarity: Polarity, enabled: bool ) -> Result<Pwm>

Constructs a new Pwm using the specified settings.

period indicates the time it takes for the PWM channel to complete one cycle.

pulse_width indicates the amount of time the PWM channel is active during a single period.

polarity configures the active logic level as either high (Normal) or low (Inverse).

enabled enables PWM on the selected channel. If enabled is set to false, the channel will remain disabled until enable is called.

This method will fail if period is shorter than pulse_width.

pub fn with_frequency( channel: Channel, frequency: f64, duty_cycle: f64, polarity: Polarity, enabled: bool ) -> Result<Pwm>

Constructs a new Pwm using the specified settings.

with_frequency is a convenience method that converts frequency to a period, and calculates the duty cycle as a percentage of the frequency.

frequency is specified in hertz (Hz).

duty_cycle is specified as a floating point value between 0.0 (0%) and 1.0 (100%).

polarity configures the active logic level as either high (Normal) or low (Inverse).

enabled enables PWM on the selected channel. If enabled is set to false, the channel will remain disabled until enable is called.

pub fn period(&self) -> Result<Duration>

Returns the period.

pub fn set_period(&self, period: Duration) -> Result<()>

Sets the period.

period indicates the time it takes for the PWM channel to complete one cycle.

This method will fail if period is shorter than the current pulse width.

pub fn pulse_width(&self) -> Result<Duration>

Returns the pulse width.

pub fn set_pulse_width(&self, pulse_width: Duration) -> Result<()>

Sets the pulse width.

pulse_width indicates the amount of time the PWM channel is active during a single period.

This method will fail if pulse_width is longer than the current period.

pub fn frequency(&self) -> Result<f64>

Returns the frequency.

frequency is a convenience method that calculates the frequency in hertz (Hz) based on the configured period.

pub fn set_frequency(&self, frequency: f64, duty_cycle: f64) -> Result<()>

Sets the frequency and duty cycle.

set_frequency is a convenience method that converts frequency to a period, and calculates the duty cycle as a percentage of the frequency.

frequency is specified in hertz (Hz).

duty_cycle is specified as a floating point value between 0.0 (0%) and 1.0 (100%).

pub fn duty_cycle(&self) -> Result<f64>

Returns the duty cycle.

duty_cycle is a convenience method that calculates the duty cycle as a floating point value between 0.0 (0%) and 1.0 (100%) based on the configured period and pulse width.

pub fn set_duty_cycle(&self, duty_cycle: f64) -> Result<()>

Sets the duty cycle.

set_duty_cycle is a convenience method that converts duty_cycle to a pulse width based on the configured period.

duty_cycle is specified as a floating point value between 0.0 (0%) and 1.0 (100%).

pub fn polarity(&self) -> Result<Polarity>

Returns the polarity.

pub fn set_polarity(&self, polarity: Polarity) -> Result<()>

Sets the polarity.

polarity configures the active logic level as either high (Normal) or low (Inverse).

pub fn is_enabled(&self) -> Result<bool>

Returns true if the PWM channel is enabled.

pub fn enable(&self) -> Result<()>

Enables the PWM channel.

pub fn disable(&self) -> Result<()>

Disables the PWM channel.

pub fn reset_on_drop(&self) -> bool

Returns the value of reset_on_drop.

pub fn set_reset_on_drop(&mut self, reset_on_drop: bool)

When enabled, disables the PWM channel when the Pwm instance goes out of scope. By default, this is set to true.

Note

Drop methods aren’t called when a process is abnormally terminated, for instance when a user presses Ctrl + C, and the SIGINT signal isn’t caught. You can catch those using crates such as simple_signal.

Trait Implementations

impl Debug for Pwm

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for Pwm

fn drop(&mut self)

Executes the destructor for this type.

impl Pwm for Pwm

fn disable(&mut self, _channel: Self::Channel)

Disables a PWM channel.

fn enable(&mut self, _channel: Self::Channel)

Enables a PWM channel.

fn get_period(&self) -> Self::Time

Returns the current PWM period.

fn get_duty(&self, _channel: Self::Channel) -> Self::Duty

Returns the current duty cycle.

fn get_max_duty(&self) -> Self::Duty

Returns the maximum duty cycle value.

fn set_duty(&mut self, _channel: Self::Channel, duty: Self::Duty)

Sets a new duty cycle.

fn set_period<P>(&mut self, period: P)where P: Into<Self::Time>,

Sets a new PWM period.

type Duty = f64

Type for the duty methods

type Channel = ()

Enumeration of channels that can be used with this Pwm interface

type Time = Duration

A time unit that can be converted into a human time unit (e.g. seconds)

impl PwmPin for Pwm

type Duty = f64

Type for the duty methods

fn disable(&mut self)

Disables a PWM channel

fn enable(&mut self)

Enables a PWM channel

fn get_duty(&self) -> Self::Duty

Returns the current duty cycle

fn get_max_duty(&self) -> Self::Duty

Returns the maximum duty cycle value

fn set_duty(&mut self, duty: Self::Duty)

Sets a new duty cycle