Module atsamd_hal::gpio

Expand description

GPIO

The GPIO module is used to configure GPIO pins through the PORT interface.

The inital GPIO API used a macro-heavy implementation, and it contained a few mistakes. The discussion in issue #214 spurred the creation of a new module with fewer macros and a corrected, refactored API.

The GPIO module has been completely rewritten (the v2 module in pre-0.15.0 HAL versions). The old module (v1) was removed in HAL version 0.15.0.

Features

Converting between pin modes no longer requires access to the Port type.

As a consequence, pin mode conversions can now be implemented using From/Into.

let pins = Pins::new(peripherals.PORT);
let pa08: Pin<PA08, PushPullOutput> = pins.pa08.into();

Defines a new AnyPin trait that can be used to simplify function arguments and reduce the number of type parameters required when dealing with GPIO pins. See the AnyPin documentation for more details.
Offers a type-erased, DynPin type, for run-time tracking of pins.
Provides a new bsp_pins macro to help BSP authors provide meaningful names and type aliases for their GPIO pins.

Pin modules

The API provides two different submodules, pin and dynpin, representing two different ways to handle GPIO pins. The default, pin, is a type-level API that tracks the state of each pin at compile-time. The alternative, dynpin is a type-erased, value-level API that tracks the state of each pin at run-time.

The type-level API is strongly preferred. By representing the state of each pin within the type system, the compiler can detect logic errors at compile-time. Furthermore, the type-level API has absolutely zero run-time cost.

If needed, dynpin can be used to erase the type-level differences between pins. However, by doing so, pins must now be tracked at run-time, and each pin has a non-zero memory footprint.

Re-exports

pub use pin::*;

pub use dynpin::*;

Modules

dynpin

Type-erased, value-level module for GPIO pins