Modern embedded framework, using Rust and async.
Find a file
Dario Nieuwenhuis 6179da6b9c stm32/dma: eagerly start transfers when calling the functions.
`async fn`s do nothing until polled, but we want the DMA transfer to
immediately start in this case. Drivers rely on it. Some require special
orders, such as "start DMA, start SPI, then wait for DMA" which is awkward
to do without eager start.

Also use a manually-impl'd future, this allows getting rid of the "double"
Unborrow channel clone.
2021-12-08 03:04:39 +01:00
.github stm32: add gpio HIL test 2021-12-06 22:05:41 +01:00
.vscode stm32: add gpio HIL test 2021-12-06 22:05:41 +01:00
embassy Some documentation corrections and expansion 2021-11-22 12:26:11 +11:00
embassy-hal-common Update to defmt 3.0ish. 2021-11-15 11:09:08 -05:00
embassy-lora Flush MISO before transfer operation 2021-12-03 09:53:28 +01:00
embassy-macros Fix interrupt_take macro by specifying path to panic macro. 2021-11-23 11:00:37 +01:00
embassy-net Fix embassy-net documentation of running examples. 2021-12-06 14:59:15 +01:00
embassy-nrf nrf/gpiote: fix build for nrf9160 2021-12-02 04:01:03 +01:00
embassy-rp Update to defmt 3.0ish. 2021-11-15 11:09:08 -05:00
embassy-stm32 stm32/dma: eagerly start transfers when calling the functions. 2021-12-08 03:04:39 +01:00
embassy-traits Fix missing lifetime bounds 2021-11-21 10:10:28 +00:00
examples Fix build examples with defmt. 2021-12-06 21:58:57 +01:00
stm32-data@3e883bdff7 Update stm32data ref 2021-12-02 18:46:53 +01:00
stm32-gen-features stm32: add stm32g4 support. 2021-11-27 02:34:23 +01:00
stm32-metapac stm32-metapac: add pac feature to allow building only the macrotables. 2021-11-24 01:04:23 +01:00
stm32-metapac-gen Update stm32-data: rcc regs info comes from yamls now. 2021-11-29 02:28:02 +01:00
tests/stm32 stm32/tests: add DMA SPI 2021-12-07 05:15:45 +01:00
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
ci.sh stm32/tests: add stm32h755zi, stm32wb55rg 2021-12-07 01:24:26 +01:00
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.