atsamd_hal

Module eic

Source
Expand description

§External Interrupt Controller

This module provides typesafe APIs for interacting with the EIC peripheral, which is used to generate interrupts based on the state of a GPIO.

Each chip has a number of EXTINT channels:

  • SAMD11: 8 channels
  • SAMD21/SAMx5x: 16 channels

Each channel can operate independently, and sense state changes for a single GPIO pin at a time. Refer to the datasheet for GPIO pin/EXTINT channel compatibility. In this module, an ExtInt represents an EXTINT channel which is tied to a GPIO Pin, and is capable of sensing state changes.

§Steps to create an ExtInt

  1. Start by creating an Eic struct, by calling Eic::new. This initializes the EIC peripheral and sets up the correct clocking.

  2. Turn the Eic into a tuple of Channels by calling Eic::split. Each channel represents a single EXTINT channel.

  3. Assign a pin to a channel by calling Channel::with_pin. This returns a fully configured and ready to use ExtInt. A Pin can also be directly converted into an ExtInt by calling one of the methods provided by the EicPin trait.

§Example setup

let eic_clock = clocks.eic(&gclk0).unwrap();
// Initialize the EIC peripheral
let eic = Eic::new(&mut peripherals.pm, eic_clock, peripherals.eic);
// Split into channels
let eic_channels = eic.split();

// Take the pin that we want to use
let button: Pin<_, PullUpInterrupt> = pins.d10.into();

// Turn the EXTINT[2] channel into an ExtInt struct
let mut extint = eic_channels.2.with_pin(button);

§async operation async

ExtInts can be used for async operations. Configuring the Eic in async mode is relatively simple:

  • Bind the corresponding EIC interrupt source to the SPI InterruptHandler (refer to the module-level async_hal documentation for more information).

  • SAMD11/SAMD21: Turn an Eic into an async-enabled Eic by calling [Eic::into_future]. Since there is only a single interrupt handler for the EIC peripheral, all EXTINT channels must be turned into async channels at once.

  • SAMx5x: Turn an individuel ExtInt into an async-enabled ExtInt by calling ExtInt::into_future. Each channel has a dedicated interrupt source, therefore you must individually choose which channels to turn into async channels.

  • Use the provided wait method. async-enabled ExtInts also implement embedded_hal_async::digital::Wait.

Structs§

  • Channel
    EIC channel.
  • Channels
    Struct generating individual handles to each EXTINT channel
  • Eic
    External Interrupt Controller.
  • ExtInt
    A numbered external interrupt, which can be used to sense state changes on its pin.
  • FutureChannels
    Struct generating individual handles to each EXTINT channel for async operation
  • InterruptHandler
    Interrupt handler used for async operations.

Enums§

  • Ch0
    Type alias for a channel number
  • Ch1
    Type alias for a channel number
  • Ch2
    Type alias for a channel number
  • Ch3
    Type alias for a channel number
  • Ch4
    Type alias for a channel number
  • Ch5
    Type alias for a channel number
  • Ch6
    Type alias for a channel number
  • Ch7
    Type alias for a channel number
  • Ch8
    Type alias for a channel number
  • Ch9
    Type alias for a channel number
  • Ch10
    Type alias for a channel number
  • Ch11
    Type alias for a channel number
  • Ch12
    Type alias for a channel number
  • Ch13
    Type alias for a channel number
  • Ch14
    Type alias for a channel number
  • Ch15
    Type alias for a channel number
  • EicFuture
    Marker type that represents an EXTINT channel capable of doing async operations.

Constants§

Traits§

  • ChId
    Trait representing an EXTINT channel ID.
  • EicPin
    Trait representing a GPIO pin which can be used as an external interrupt.

Type Aliases§