Struct rppal::gpio::IoPin

pub struct IoPin { /* private fields */ }

GPIO pin that can be (re)configured for any mode or alternate function.

IoPins are constructed by converting a Pin using Pin::into_io. The pin’s mode is automatically set to the specified mode.

An IoPin can be reconfigured for any available mode. Depending on the mode, some methods may not have any effect. For instance, calling a method that alters the pin’s output state won’t cause any changes when the pin’s mode is set to Input.

The embedded-hal digital::OutputPin and PwmPin trait implementations for IoPin can be enabled by specifying the optional hal feature in the dependency declaration for the rppal crate.

The unproven embedded-hal digital::InputPin, digital::StatefulOutputPin, digital::ToggleableOutputPin and Pwm trait implementations for IoPin can be enabled by specifying the optional hal-unproven feature in the dependency declaration for the rppal crate.

Implementations

impl IoPin

pub fn pin(&self) -> u8

Returns the GPIO pin number.

Pins are addressed by their BCM numbers, rather than their physical location.

pub fn mode(&self) -> Mode

Returns the pin’s mode.

pub fn set_mode(&mut self, mode: Mode)

Sets the pin’s mode.

pub fn set_bias(&mut self, bias: Bias)

Configures the built-in pull-up/pull-down resistors.

pub fn read(&self) -> Level

Reads the pin’s logic level.

pub fn is_low(&self) -> bool

Reads the pin’s logic level, and returns true if it’s set to Low.

pub fn is_high(&self) -> bool

Reads the pin’s logic level, and returns true if it’s set to High.

pub fn write(&mut self, level: Level)

Sets the pin’s output state.

pub fn set_low(&mut self)

Sets the pin’s output state to Low.

pub fn set_high(&mut self)

Sets the pin’s output state to High.

pub fn toggle(&mut self)

Toggles the pin’s output state between Low and High.

pub fn set_pwm(&mut self, period: Duration, pulse_width: Duration) -> Result<()>

Configures a software-based PWM signal.

period indicates the time it takes to complete one cycle.

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

Software-based PWM is inherently inaccurate on a multi-threaded OS due to scheduling/preemption. If an accurate or faster PWM signal is required, use the hardware Pwm peripheral instead. More information can be found here.

If set_pwm is called when a PWM thread is already active, the existing thread will be reconfigured at the end of the current cycle.

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

Configures a software-based PWM signal.

set_pwm_frequency is a convenience method that converts frequency to a period and duty_cycle to a pulse width, and then calls set_pwm.

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 clear_pwm(&mut self) -> Result<()>

Stops a previously configured software-based PWM signal.

The thread responsible for emulating the PWM signal is stopped at the end of the current cycle.

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, resets the pin’s mode to its original state and disables the built-in pull-up/pull-down resistors when the pin 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 IoPin

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

Formats the value using the given formatter.

impl Drop for IoPin

fn drop(&mut self)

Resets the pin’s mode and disables the built-in pull-up/pull-down resistors if reset_on_drop is set to true (default).

impl<'a> PartialEq<&'a IoPin> for IoPin

fn eq(&self, other: &&'a IoPin) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> PartialEq<IoPin> for &'a IoPin

fn eq(&self, other: &IoPin) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<IoPin> for IoPin

fn eq(&self, other: &IoPin) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for IoPin