Hal update and async implementation

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "switch-hal"
-version = "0.4.0"
+version = "0.5.0"
 authors = ["Christopher J. McClellan <[email protected]>"]
 edition = "2018"
 description = "HAL and basic implementations for input and output switches (buttons, switches, leds, transistors)"
@@ -16,6 +16,19 @@ exclude = [
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
+[features]
+default = []
+async = ["dep:embedded-hal-async"]
+
 [dependencies.embedded-hal]
-version = "0.2.5"
-features = [ "unproven" ]
+version = "1.0"
+
+[dependencies.embedded-hal-async]
+version = "1.0"
+optional = true
+
+[dev-dependencies.noop-waker]
+version = "0.1"
+
+[dev-dependencies.assert_matches]
+version = "1.5"

src/input/mod.rs

@@ -1,18 +1,70 @@
+#[cfg(feature = "async")]
+use crate::WaitableInputSwitch;
 use crate::{ActiveHigh, ActiveLow, InputSwitch, Switch};
-use embedded_hal::digital::v2::InputPin;
+use embedded_hal::digital::{ErrorType, InputPin};
+#[cfg(feature = "async")]
+use embedded_hal_async::digital::Wait;
 
 impl<T: InputPin> InputSwitch for Switch<T, ActiveHigh> {
-    type Error = <T as InputPin>::Error;
+    type Error = <T as ErrorType>::Error;
 
     fn is_active(&self) -> Result<bool, Self::Error> {
-        self.pin.is_high()
+        self.pin.borrow_mut().is_high()
     }
 }
 
 impl<T: InputPin> InputSwitch for Switch<T, ActiveLow> {
-    type Error = <T as InputPin>::Error;
+    type Error = <T as ErrorType>::Error;
 
     fn is_active(&self) -> Result<bool, Self::Error> {
-        self.pin.is_low()
+        self.pin.borrow_mut().is_low()
+    }
+}
+
+#[cfg(feature = "async")]
+impl<T: Wait + InputPin> WaitableInputSwitch for Switch<T, ActiveHigh>
+where
+    Switch<T, ActiveHigh>: InputSwitch,
+{
+    type Error = <T as ErrorType>::Error;
+
+    async fn wait_for_active(&mut self) -> Result<(), Self::Error> {
+        self.pin.get_mut().wait_for_high().await
+    }
+
+    async fn wait_for_inactive(&mut self) -> Result<(), Self::Error> {
+        self.pin.get_mut().wait_for_low().await
+    }
+
+    async fn wait_for_change(&mut self) -> Result<(), Self::Error> {
+        if self.pin.get_mut().is_high()? {
+            self.pin.get_mut().wait_for_low().await
+        } else {
+            self.pin.get_mut().wait_for_high().await
+        }
+    }
+}
+
+#[cfg(feature = "async")]
+impl<T: Wait + InputPin> WaitableInputSwitch for Switch<T, ActiveLow>
+where
+    Switch<T, ActiveHigh>: InputSwitch,
+{
+    type Error = <T as ErrorType>::Error;
+
+    async fn wait_for_active(&mut self) -> Result<(), Self::Error> {
+        self.pin.get_mut().wait_for_low().await
+    }
+
+    async fn wait_for_inactive(&mut self) -> Result<(), Self::Error> {
+        self.pin.get_mut().wait_for_high().await
+    }
+
+    async fn wait_for_change(&mut self) -> Result<(), Self::Error> {
+        if self.pin.get_mut().is_high()? {
+            self.pin.get_mut().wait_for_low().await
+        } else {
+            self.pin.get_mut().wait_for_high().await
+        }
     }
 }

src/lib.rs

@@ -1,4 +1,7 @@
+//! "Async" feature enables async support for input switches.
+
 #![no_std]
+#![allow(async_fn_in_trait)]
 
 mod input;
 mod output;
@@ -19,7 +22,7 @@ pub trait InputSwitch {
     /// use switch_hal::{InputSwitch, OutputSwitch, Switch, IntoSwitch};
     /// # let pin = mock::Pin::with_state(mock::State::High);
     /// # let mut status_led = mock::Pin::new().into_active_high_switch();
-    /// let button = pin.into_active_low_switch();
+    /// let mut button = pin.into_active_low_switch();
     /// match button.is_active() {
     ///     Ok(true) => { status_led.on().ok(); }
     ///     Ok(false) => { status_led.off().ok(); }
@@ -29,6 +32,22 @@ pub trait InputSwitch {
     fn is_active(&self) -> Result<bool, Self::Error>;
 }
 
+#[cfg(feature = "async")]
+/// Represents an input switch that can be asynchronously waited for
+pub trait WaitableInputSwitch {
+    type Error;
+
+    /// Waits until the switch becomes active. If the switch in already active, returns immediately
+    /// 
+    async fn wait_for_active(&mut self) -> Result<(), Self::Error>;
+    /// Waits until the switch becomes inactive. If the switch is already inactive, returns immediately
+    /// 
+    async fn wait_for_inactive(&mut self) -> Result<(), Self::Error>;
+    /// Waits until the switch changess from active to inactive, or from inactive to active
+    /// 
+    async fn wait_for_change(&mut self) -> Result<(), Self::Error>;
+}
+
 /// Represents an output switch, such as a LED "switch" or transistor
 pub trait OutputSwitch {
     type Error;
@@ -63,11 +82,11 @@ pub trait OutputSwitch {
 /// Toggles the switch from it's current state to it's opposite state.
 ///
 /// # Notes
-/// This is only available if the underlying hal has implemented [ToggleableOutputPin](embedded_hal::digital::v2::ToggleableOutputPin)
+/// This is only available if the underlying hal has implemented [StatefulOutputPin](embedded_hal::digital::StatefulOutputPin)
 pub trait ToggleableOutputSwitch {
     type Error;
 
-    /// Toggles the current state of the [OutputSwitch](OutputSwitch)
+    /// Toggles the current state of the [OutputSwitch]
     ///
     /// # Examples
     ///
@@ -84,7 +103,7 @@ pub trait ToggleableOutputSwitch {
 /// Checks current switch state
 ///
 /// # Notes
-/// This is only available if the underlying hal has implemented [StatefulOutputPin](embedded_hal::digital::v2::StatefulOutputPin)
+/// This is only available if the underlying hal has implemented [StatefulOutputPin](embedded_hal::digital::StatefulOutputPin)
 pub trait StatefulOutputSwitch {
     type Error;
 
@@ -98,7 +117,7 @@ pub trait StatefulOutputSwitch {
     /// # let pin = mock::Pin::new();
     /// let mut led = pin.into_active_high_switch();
     /// led.off().ok();
-    /// assert!(!led.is_on().unwrap());
+    /// assert_eq!(false, led.is_on().unwrap());
     /// ```
     fn is_on(&mut self) -> Result<bool, Self::Error>;
 
@@ -112,7 +131,7 @@ pub trait StatefulOutputSwitch {
     /// # let pin = mock::Pin::new();
     /// let mut led = pin.into_active_high_switch();
     /// led.off().ok();
-    /// assert!(led.is_off().unwrap());
+    /// assert_eq!(true, led.is_off().unwrap());
     /// ```
     fn is_off(&mut self) -> Result<bool, Self::Error>;
 }
@@ -122,23 +141,23 @@ pub struct ActiveHigh;
 /// Zero sized struct for signaling to [Switch](struct.Switch.html) that it is active low
 pub struct ActiveLow;
 
-use core::marker::PhantomData;
+use core::{cell::RefCell, marker::PhantomData};
 
 /// Concrete implementation for [InputSwitch](trait.InputSwitch.html) and [OutputSwitch](trait.OutputSwitch.html)
 ///
 /// # Type Params
-/// - `IoPin` must be a type that implements either of the [InputPin](embedded_hal::digital::v2::InputPin) or [OutputPin](embedded_hal::digital::v2::OutputPin) traits.
-/// - `ActiveLevel` indicates whether the `Switch` is [ActiveHigh](ActiveHigh) or [ActiveLow](ActiveLow).
+/// - `IoPin` must be a type that implements either of the [InputPin](embedded_hal::digital::InputPin) or [OutputPin](embedded_hal::digital::OutputPin) traits.
+/// - `ActiveLevel` indicates whether the `Switch` is [ActiveHigh] or [ActiveLow].
 ///     `ActiveLevel` is not actually stored in the struct.
-///     It's [PhantomData](core::marker::PhantomData) used to indicate which implementation to use.
+///     It's [PhantomData] used to indicate which implementation to use.
 pub struct Switch<IoPin, ActiveLevel> {
-    pin: IoPin,
+    pin: RefCell<IoPin>,
     active: PhantomData<ActiveLevel>,
 }
 
 impl<IoPin, ActiveLevel> Switch<IoPin, ActiveLevel> {
     /// Constructs a new [Switch](struct.Switch.html) from a concrete implementation of an
-    /// [InputPin](embedded_hal::digital::v2::InputPin) or [OutputPin](embedded_hal::digital::v2::OutputPin)
+    /// [InputPin](embedded_hal::digital::InputPin) or [OutputPin](embedded_hal::digital::OutputPin)
     ///
     /// **Prefer the [IntoSwitch](trait.IntoSwitch.html) trait over calling [new](#method.new) directly.**
     ///
@@ -183,12 +202,12 @@ impl<IoPin, ActiveLevel> Switch<IoPin, ActiveLevel> {
     /// ```
     pub fn new(pin: IoPin) -> Self {
         Switch {
-            pin: pin,
+            pin: RefCell::new(pin),
             active: PhantomData::<ActiveLevel>,
         }
     }
 
-    /// Consumes the [Switch](struct.Switch.html) and returns the underlying [InputPin](embedded_hal::digital::v2::InputPin) or [OutputPin](embedded_hal::digital::v2::OutputPin).
+    /// Consumes the [Switch](struct.Switch.html) and returns the underlying [InputPin](embedded_hal::digital::InputPin) or [OutputPin](embedded_hal::digital::OutputPin).
     ///
     /// This is useful fore retrieving the underlying pin to use it for a different purpose.
     ///
@@ -204,19 +223,18 @@ impl<IoPin, ActiveLevel> Switch<IoPin, ActiveLevel> {
     /// // do something else with the pin
     /// ```
     pub fn into_pin(self) -> IoPin {
-        self.pin
+        self.pin.into_inner()
     }
 }
 
-/// Convenience functions for converting [InputPin](embedded_hal::digital::v2::InputPin)
-/// and [OutputPin](embedded_hal::digital::v2::OutputPin) to a [Switch](struct.Switch.html).
+/// Convenience functions for converting [InputPin](embedded_hal::digital::InputPin)
+/// and [OutputPin](embedded_hal::digital::OutputPin) to a [Switch](struct.Switch.html).
 ///
 /// The type of [Switch](struct.Switch.html) returned,
 /// [InputSwitch](trait.InputSwitch.html) or [OutputSwitch](trait.OutputSwitch.html) is
-/// determined by whether the `IoPin` being consumed is an [InputPin](embedded_hal::digital::v2::InputPin)
-/// or [OutputPin](embedded_hal::digital::v2::OutputPin).
+/// determined by whether the `IoPin` being consumed is an [InputPin](embedded_hal::digital::InputPin)
+/// or [OutputPin](embedded_hal::digital::OutputPin).
 pub trait IntoSwitch {
-
     /// Consumes the `IoPin` returning a [Switch](struct.Switch.html) of the appropriate `ActiveLevel`.
     ///
     /// This method exists so other, more convenient functions, can have blanket implementations.