Add support for splitting esp32 uart into TX and RX

[Georges760]

• Keeps existing API for uart, but wraps it in Tx and Rx sub-types
• Adds split() method similar to embassy-rs nRF/stm32/rp for getting indepdendent TX and RX parts
• Implements e-h traits for TX and RX types
• Add esp32s3 example

Thank you!

Thank you for your contribution.
Please make sure that your submission includes the following:

Must

• The code compiles without errors or warnings.
• All examples work.
• cargo fmt was run.
• Your changes were added to the CHANGELOG.md in the proper section.
• You updated existing examples or added examples (if applicable).
• Added examples are checked in CI

Nice to have

• You add a description of your work to this PR.
• You added proper docs for your newly added features and code.

[Georges760]

Do anyone know why the Instance type is not propagated to UartFuture in the new() constructor ?

It is well propagated from Uart to UartRx and UartTx in their new_inner() contructor.

Is it because UartFuture lives in a sub mod Asynch ?

[MabezDev]

Sorry, missed this completely!

To fix the current compilation errors, you just need to specify that the T used by the UartFuture is the same T from the UartRx/Tx. I.e UartFuture::new( => UartFuture::<T>::new(. This seems to be a quirk of async Rust, as normal functions can infer this usually.

[Georges760]

why do my cargo fmt is not the same as the one from CI ?

$ cargo fmt --version
rustfmt 1.6.0-stable (5680fa1 2023-08-23)

[MabezDev]

This is looking good functionality wise, but could we improve the example? What about sending the read bytes over a channel to the write to be written back out? As it stands the example isn't very interactive. We can also drop the AT command stuff for this example.

[MabezDev]

Another alternative would be to instead of adding a new example, change the current embassy_serial one to use split by default.

[Georges760]

Another alternative would be to instead of adding a new example, change the current embassy_serial one to use split by default.

OK I will do that. Sorry I have very few time for this now...

[Georges760]

i did mess up my repo while rebasing, and this close the PR. sorry

[MabezDev]

Thanks @Georges760! LGTM!