Embedded HAL Compatibility Layer

A compatibility layer to smooth the transition between different versions of embedded-hal (specifically 0.2.x and 1.0.0-alpha.X series).

This resolves the problem where a HAL implementation (ie. the implementation for your processor) and driver you intend to use are mismatched.

This crate is intended to track 1.0.0-alpha versions, and update to 1.0.0 on release, adaptation is not provided between 1.0.0-alpha.x releases (though we could do this if it was deemed worthwhile)

Supported Versions

Each release of embedded-hal-compat supports one(ish) pair of e-h releases, because of changes to the 1.0.0-alpha, use:

• embedded-hal-compat = "0.13.0" for =1.0.0 and ^0.2.7
• embedded-hal-compat = "0.12.0" for =1.0.0-rc.1 and ^0.2.7
• embedded-hal-compat = "0.11.0" for =1.0.0-alpha.11 and ^0.2.7
• embedded-hal-compat = "0.10.0" for =1.0.0-alpha.10 and ^0.2.7
• embedded-hal-compat = "0.7.0" for =1.0.0-alpha.8 and ^0.2.4
• embedded-hal-compat = "0.6.0" for =1.0.0-alpha.7 and ^0.2.4
• embedded-hal-compat = "0.5.0" for =1.0.0-alpha.6 and ^0.2.4
• embedded-hal-compat = "0.4.0" for =1.0.0-alpha.5 and ^0.2.4
• embedded-hal-compat = "0.3.0" for =1.0.0-alpha.4 and ^0.2.4

Status

Not all wrappers are fully implemented, feel free to open a PR if you come across something missing!

How to use this:

• Add embedded-hal-compat to your dependencies
• Import with use embedded_hal_compat::{ForwardCompat, ReverseCompat};
• Vicariously add .forward() or .reverse() on any embedded-hal type mismatches
• See docs.rs for further documentation

How do I know that I need this?

Type errors. Lots of type errors.

(and cargo tree -i embedded-hal returns two versions)

Is this cursed?!

At least a little bit, because traits have the same method names you might end up with some cursed errors, and we have to pave over some differences around errors and error kinds...

What kind of errors?

Because you're likely to have symbols with the same name you'll end up with errors like:

error[E0599]: no method named `delay_ms` found for mutable reference `&mut Compat<atsamd_hal::delay::Delay>` in the current scope
   --> src/main.rs:351:27
    |
351 |         tlv.inner_delay().delay_ms(10u32);
    |                           ^^^^^^^^ method not found in `&mut Compat<atsamd_hal::delay::Delay>`

warning: unused import: `embedded_hal::blocking::delay::DelayMs`
  --> src/main.rs:22:5
   |
22 | use embedded_hal::blocking::delay::DelayMs;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Suggesting you're missing an import that's obviously there, because you have the 0.2.x imports not the 1.0.0-alpha.x imports, and the method is called try_delay_ms in the updated HAL (a fairly common renaming).

You can fix this by importing the correct trait with something like: use embedded_hal_compat::eh1_0::blocking::delay::{DelayMs as _}; (this must be renamed with as / you can't use the prelude because the names overlap), and by swapping the method to use the correct try_ name.