From e93f2679b1edbedd83e09fbc3b7a07dbf1ef80a4 Mon Sep 17 00:00:00 2001 From: Ulf Lilleengen Date: Fri, 10 Dec 2021 12:27:44 +0100 Subject: More content --- docs/modules/ROOT/pages/basic_application.adoc | 15 +++++++++++++-- docs/modules/ROOT/pages/stm32.adoc | 23 ++++++++++++++++++++++- 2 files changed, 35 insertions(+), 3 deletions(-) (limited to 'docs/modules') diff --git a/docs/modules/ROOT/pages/basic_application.adoc b/docs/modules/ROOT/pages/basic_application.adoc index d56cb5e1..53aaa3d7 100644 --- a/docs/modules/ROOT/pages/basic_application.adoc +++ b/docs/modules/ROOT/pages/basic_application.adoc @@ -3,8 +3,6 @@ So you've got one of the xref:examples.adoc[examples] running, but what now? Let's go through a simple Embassy application for the nRF52 DK to understand it better. -== The Cargo.toml - == The main === Rust Nightly @@ -73,3 +71,16 @@ What happens when the `blinker` task have been spawned and main returns? Well, t . Runs the executor spawning the main task There is also a way to run the executor without using the macro, in which case you have to create the `Executor` instance yourself. + +== The Cargo.toml + +The project definition needs to contain the embassy dependencies: + +[source,toml] +---- +include::example$examples/nrf/Cargo.toml[lines="9..11"] +---- + +Depending on your microcontroller, you may need to replace `embassy-nrf` with something else (`embassy-stm32` for STM32. Remember to update feature flags as well). + +In this particular case, the nrf52840 chip is selected, and the RTC1 peripheral is used as the time driver. diff --git a/docs/modules/ROOT/pages/stm32.adoc b/docs/modules/ROOT/pages/stm32.adoc index 328f69e2..3d1fbfc8 100644 --- a/docs/modules/ROOT/pages/stm32.adoc +++ b/docs/modules/ROOT/pages/stm32.adoc @@ -1,3 +1,24 @@ = Embassy STM32 HAL -TODO +The link:https://github.com/embassy-rs/embassy/tree/master/embassy-stm32[Embassy STM32 HAL] is based on the `stm32-metapac` project. + +== The infinite variant problem + +STM32 microcontrollers comes in many families and flavors, and supporting all of them is a big undertaking. Embassy has taken advantage of the fact +that the STM32 peripheral versions are shared across chip families. Instead of re-implementing the SPI +peripheral for every STM32 chip family, embassy have a single SPI implementation that depends on +code-generated register types that are identical for STM32 families with the same version of a given peripheral. + +=== The metapac + +The `stm32-metapac` module uses pre-generated chip and register definitions for STM32 chip families to generate register types. This is done at compile time based on Cargo feataure flags. + +The chip and register definitions are located in a separate module, `stm32-data`, which is modified whenever a bug is found in the definitions, or when adding support for new chip families. + +=== The HAL + +The `embassy-stm32` module contains the HAL implementation for all STM32 families. The implementation uses automatically derived feature flags to support the correct version of a given peripheral for a given chip family. + +== Timer driver + +The STM32 timer driver operates at 32768 Hz by default. -- cgit v1.2.3