982f5a9a19
586: stm32: add `time-driver-any` cargo feature that automatically picks one. r=Dirbaio a=Dirbaio Most of the time you don't care which one gets used, so this is easier! :) It also helps for building docs for all chips, it reduces the feature changes needed. Co-authored-by: Dario Nieuwenhuis <dirbaio@dirbaio.net> |
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.github | ||
.vscode | ||
docs | ||
embassy | ||
embassy-hal-common | ||
embassy-lora | ||
embassy-macros | ||
embassy-net | ||
embassy-nrf | ||
embassy-rp | ||
embassy-stm32 | ||
embassy-traits | ||
examples | ||
stm32-data@97877b42a7 | ||
stm32-gen-features | ||
stm32-metapac | ||
stm32-metapac-gen | ||
tests/stm32 | ||
xtask | ||
.gitignore | ||
.gitmodules | ||
ci.sh | ||
LICENSE-APACHE | ||
LICENSE-MIT | ||
README.md | ||
rust-toolchain.toml |
Embassy
Embassy is a project to make async/await a first-class option for embedded development. For more information and instructions to get started, go to https://embassy.dev.
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, essentiallyno_std
compatible versions offutures::io
.embassy::traits::flash
: Flash device trait.embassy::time
:Clock
andAlarm
traits. Std-likeDuration
andInstant
.- 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).
HALs
Hardware Absraction Layers with asynchronous behaviors are provided for a variety of platforms.
For example, the embassy-nrf
crate contains implementations for nRF 52 series SoCs.
-
uarte
: UARTE driver implementingAsyncBufRead
andAsyncWrite
. -
qspi
: QSPI driver implementingFlash
. -
gpiote
: GPIOTE driver. Allowsawait
ing 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 implementingClock
andAlarm
, for use withembassy::executor
.
Examples
Examples are found in the examples/
folder seperated by the chip manufacturer they are designed to run on. For example:
examples/nrf
are designed to run on thenrf52840-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
- Change directory to the sample's base directory. For example:
cd examples/nrf
- Run the example
For example:
cargo run --bin blinky
Developing Embassy with Rust Analyzer based editors
The Rust Analyzer is used by Visual Studio Code
and others. Given the multiple targets that Embassy serves, there is no Cargo workspace file. Instead, the Rust Analyzer
must be told of the target project to work with. In the case of Visual Studio Code,
please refer to the .vscode/settings.json
file's rust-analyzer.linkedProjects
setting.
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 withasync{}
blocks, and forstatic-executor
.
Stable support is a non-goal until these features get stabilized.
Documentation
Embassy documentation is located in the docs/
folder. The documentation is built in embassy-book and published to https://embassy.dev by CI.
Why the name?
EMBedded ASYnc! :)
License
This work is 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.