switch-hal

Switch-HAL is a no_std embedded Rust library for working with buttons, switches, LEDs, and transistors. Basically, anything that acts like a switch, whether an input or output.

It is both a driver that uses the embedded-hal::digital traits and is an abstraction in it's own right. It provides a simple, zero-cost, abstraction to clarify the intent of your application code.

Why Switch-HAL? Why not just use raw GPIO?

Did you mean to drive that line high?
Or did you mean to turn that LED off?
Wait a second... is that LED active high?
Where's the schematic?
Okay... cathode is wired to the input line... that means it's active low.

Now repeat this every place in your code where you need to turn that LED on or off.
What happens when the hardware changes?
Using the raw GPIO to set pins high and low will have you making changes all over your code base.

Wouldn't it be nicer if you only had to think about that once, when you initialize your application,
and from then on out, simply called led.on() or led.off().
Having an abstraction at the proper level reduces cognitive load.
Specifying whether a simple peripheral is active high or low in a single place in your application reduces the maintenance burden.

Documentation

https://docs.rs/crate/switch-hal

or build a local copy

cargo docs

and open target/doc/switch_hal/index.html in your browser.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Architectural Decision Records

Major design decisions are tracked in the adr directory.

Changelog

0.4.0

Adds StatefulOutputSwitch thanks to forkbomb9

0.3.3

Update embedded-hal to 0.2.5

0.3.2

• Add convenience converter functions into_active_low_switch() and into_active_high_switch()

0.3.1

• Bug Fix: is_active() was returning the wrong result for Switch<InputPin, ActiveLow>