Modern embedded framework, using Rust and async.
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bors[bot] 569ecd699d
Merge #467
467: docs: fix some `cargo doc` warnings r=lulf a=numero-744

There are still 3 warnings (below)

```
 Documenting embassy v0.1.0 (embassy)
warning: unresolved link to `channel`
   --> src/channel/mpsc.rs:241:22
    |
241 |     /// [`channel`]: channel
    |                      ^^^^^^^ no item named `channel` in scope
    |
    = note: `#[warn(rustdoc::broken_intra_doc_links)]` on by default
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`

warning: unresolved link to `Task::spawn`
   --> src/executor/raw/mod.rs:105:12
    |
105 | /// with [`Task::spawn()`], which will fail if it is already spawned.
    |            ^^^^^^^^^^^^^ no item named `Task` in scope

warning: public documentation for `spawn` links to private item `Executor::spawn`
   --> src/executor/raw/mod.rs:156:17
    |
156 |     /// cause [`Executor::spawn()`] to return the error.
    |                 ^^^^^^^^^^^^^^^^^ this item is private
    |
    = note: `#[warn(rustdoc::private_intra_doc_links)]` on by default
    = note: this link will resolve properly if you pass `--document-private-items`

warning: `embassy` (lib doc) generated 3 warnings
```

Co-authored-by: Côme ALLART <come.allart@etu.emse.fr>
2021-11-02 19:31:15 +00:00
.github Merge #457 2021-10-27 22:43:35 +00:00
.vscode Clippy fixes 2021-10-18 01:05:29 +02:00
embassy Merge #467 2021-11-02 19:31:15 +00:00
embassy-hal-common Clippy fixes 2021-10-18 01:05:29 +02:00
embassy-lora Use upstream version of rust-lorawan 2021-10-22 19:33:15 +02:00
embassy-macros Clippy fixes 2021-10-18 01:05:29 +02:00
embassy-net Clippy fixes 2021-10-18 01:05:29 +02:00
embassy-nrf Update versions of critical-section and atomic-polyfill 2021-11-02 18:52:03 +01:00
embassy-rp Update versions of critical-section and atomic-polyfill 2021-11-02 18:52:03 +01:00
embassy-stm32 Update versions of critical-section and atomic-polyfill 2021-11-02 18:52:03 +01:00
embassy-traits Add IntoIterator trait bound on Future trait's parameter 2021-10-29 20:37:00 +01:00
examples Update versions of critical-section and atomic-polyfill 2021-11-02 18:52:03 +01:00
stm32-data@8d3ca7adc6 Update stm32-data to main 2021-10-26 21:45:08 +02:00
stm32-gen-features Initial support for STM32F767ZI. 2021-10-26 17:33:28 +02:00
stm32-metapac Support for STM32L1 2021-09-21 14:50:23 +02:00
stm32-metapac-gen Workaround duplicity of DMA channel declaration when the target chip specifies more than one request, by processing only the first declared request for the channel. 2021-10-22 11:36:47 +02:00
xtask Update lots of deps 2021-09-11 01:35:23 +02:00
.gitignore Update lots of deps 2021-09-11 01:35:23 +02:00
.gitmodules Add stm32-metapac crate, with codegen in rust 2021-05-31 02:40:58 +02:00
Cargo.example.toml Add missing examples to Cargo.example.toml 2021-10-26 17:33:28 +02:00
LICENSE-APACHE First commit 2020-09-22 18:03:43 +02:00
LICENSE-MIT First commit 2020-09-22 18:03:43 +02:00
README.md Extend SAADC one shot support 2021-10-09 11:25:18 +11:00
rust-toolchain.toml Update nightly 2021-10-18 01:26:06 +02:00

Embassy

Embassy is a project to make async/await a first-class option for embedded development. For more information and instructions to get started, click here.

Traits and types

embassy provides a set of traits and types specifically designed for async usage.

  • embassy::io: AsyncBufRead, AsyncWrite. Traits for byte-stream IO, essentially no_std compatible versions of futures::io.
  • embassy::traits::flash: Flash device trait.
  • embassy::time: Clock and Alarm traits. Std-like Duration and Instant.
  • More traits for SPI, I2C, UART async HAL coming soon.

Executor

The embassy::executor module provides an async/await executor designed for embedded usage.

  • No alloc, no heap needed. Task futures are statically allocated.
  • No "fixed capacity" data structures, executor works with 1 or 1000 tasks without needing config/tuning.
  • Integrated timer queue: sleeping is easy, just do Timer::after(Duration::from_secs(1)).await;.
  • No busy-loop polling: CPU sleeps when there's no work to do, using interrupts or WFE/SEV.
  • Efficient polling: a wake will only poll the woken task, not all of them.
  • Fair: a task can't monopolize CPU time even if it's constantly being woken. All other tasks get a chance to run before a given task gets polled for the second time.
  • Creating multiple executor instances is supported, to run tasks with multiple priority levels. This allows higher-priority tasks to preempt lower-priority tasks.

Utils

embassy::util contains some lightweight async/await utilities, mainly helpful for async driver development (signaling a task that an interrupt has occured, for example).

embassy-nrf

The embassy-nrf crate contains implementations for nRF 52 series SoCs.

  • uarte: UARTE driver implementing AsyncBufRead and AsyncWrite.

  • qspi: QSPI driver implementing Flash.

  • gpiote: GPIOTE driver. Allows awaiting GPIO pin changes. Great for reading buttons or receiving interrupts from external chips.

  • saadc: SAADC driver. Provides a full implementation of the one-shot sampling for analog channels.

  • rtc: RTC driver implementing Clock and Alarm, for use with embassy::executor.

Examples

Examples are found in the examples/ folder seperated by the chip manufacturer they are designed to run on:

  • examples/nrf are designed to run on the nrf52840-dk board (PCA10056) but should be easily adaptable to other nRF52 chips and boards.
  • examples/rp are for the RP2040 chip.
  • examples/stm32 are designed for the STM32F429ZI chip but should be easily adaptable to other STM32F4xx chips.
  • examples/std are designed to run locally on your pc.

Running examples

  • Setup git submodules (needed for STM32 examples)
git submodule init
git submodule update
  • Install probe-run with defmt support.
cargo install probe-run
  • Run the example
cargo run --bin rtc_async

Minimum supported Rust version (MSRV)

Required nightly version is specified in the rust-toolchain.toml file. Nightly is required for:

  • generic_associated_types: for trait funcs returning futures.
  • type_alias_impl_trait: for trait funcs returning futures implemented with async{} blocks, and for static-executor.

Stable support is a non-goal until these features get stabilized.

Why the name?

EMBedded ASYnc! :)

License

This work is licensed under either of

at your option.