embassy VS avr-hal

thanks. looked that up. for the curious: https://embassy.dev/

Running the Embassy RP2040 USB CDC ACM serial example takes about 5 seconds on a Pico.

https://github.com/embassy-rs/embassy/blob/main/examples/rp/...

Async solves different problems, you can, for instance, have just a single-threaded CPU and still have a nice API if you have async-await. It might not be so cool at a higher level as Go's approach of channels and threads, but it's cool in embedded, read this:

https://github.com/embassy-rs/embassy?tab=readme-ov-file#rus...

"Rust's async/await allows for unprecedently easy and efficient multitasking in embedded systems. Tasks get transformed at compile time into state machines that get run cooperatively. It requires no dynamic memory allocation, and runs on a single stack, so no per-task stack size tuning is required. It obsoletes the need for a traditional RTOS with kernel context switching, and is faster and smaller than one!"

I'm just toying with Raspberry Pi Pico and it's pretty nice.

Go and Rust have different use cases, the async-await is nice at a low level.

I have not yet dipped by toes in the Rust waters, but reading about the embassy project is actually what piqued my curiosity about using C++ coroutines in embedded. Are you familiar with the project or have you found it lacking?

I think I get the basics (shoutout to the Rust Embedded Working Group!), and I've started looking for the stack I'd be using. I think Embassy is really amazing, as well as the work of the ESP team -- hats off.

> }

And this is how to do it using embassy, which is an async framework for embedded in rust:

https://github.com/embassy-rs/embassy/blob/main/examples/rp/...

> not good for embedded

embassy begs to differ

https://embassy.dev/

async/await is really just a syntax for building state machines in a way that resembles regular code. It's compiled down to the same code that you would write by hand anyway (early on it had some bloat in state size but I think it's all fixed now).

And embedded has a lot of state machines!

You can run multiple executors at different interrupt priority levels (with multiple tasks per executor), which allows tasks on the higher priority executor to interrupt other tasks. Here's an example https://github.com/embassy-rs/embassy/blob/main/examples/nrf...

/* * For examples (and inspiration), head to * * https://github.com/Rahix/avr-hal/tree/main/examples * * NOTE: Not all examples were ported to all boards! There is a good chance though, that code * for a different board can be adapted for yours. The Arduino Uno currently has the most * examples available. */ #![no_std] #![no_main] use dht_sensor::*; use panic_halt as _; #[arduino_hal::entry] fn main() -> ! { let dp = arduino_hal::Peripherals::take().unwrap(); let pins = arduino_hal::pins!(dp); let mut serial = arduino_hal::default_serial!(dp, pins, 57200); let mut pin3 = pins.d3.into_opendrain_high(); let mut delay = arduino_hal::Delay::new(); ufmt::uwriteln!(serial, "{}", "waiting for sensor...").unwrap(); arduino_hal::delay_ms(2000); loop { match dht11::Reading::read(&mut delay, &mut pin3) { Ok(dht11::Reading { temperature, relative_humidity, }) => ufmt::uwriteln!(serial, "{}°, {}% RH", temperature, relative_humidity).unwrap(), Err(_e) => ufmt::uwriteln!(serial, "Error {}", "Unable to read").unwrap(), } arduino_hal::delay_ms(2000); } }

I found the generics a lot less of a problem when I realized I could parametrize on things like embedded_hal::serial::Write instead of UsartOps https://github.com/Rahix/avr-hal/pull/264/commits/17ed15321cb8fcf8aedb1f8133be1f189eb06a6f

I've come across avr-rust, avr-hal and both seem to have arduino stuff, wondering which is the most beginner friendly? (I have a bit of experience with the regular arduino IDE but want to switch over to doing all the stuff in rust for a challenge)

fyi, a minor follow-up at https://github.com/Rahix/avr-hal/issues/388

I have contributed a little to this. avr-hal I have done a couple little hobby projects with it as well, but I can't say it's the best thing out there.

All you need is in the documentation: https://rahix.github.io/avr-hal/arduino_hal/index.html even though reading the documentation without knowing what you're looking for can be quite difficult, so looking at some examples might be more helpful.

Rust language shares all advantages of efficient C++ code. With the rust community growing year after year, more and more people try using rust to program their Arduino boards. Consequently, the Arduino Rust ecosystem have significantly developed in the last couple of years. The Hardware Abstraction Layer for AVR microcontrollers avr-hal, Rudino library and ravedude CLI utility to make Rust development for AVR microcontrollers easier are just a few examples of the solid foundation developed so far.

Today I was toying with the arduino again, making an attached LED matrix print awesome messages better than it previously had. I wanted to use millis() found in the examples in the unsurpassed avr-hal crate, to orchestrate the duration it should show (part of) a character before moving on. But that is all besides the point. I made a few mistakes that coincidentally compiled and as such made me believe I was doing things right. (Perhaps I should note here that I am visually impaired so it is a bit easier for me to glance over smaller differences.)

There's a blink example in the repo for the avr-hal crate.

I'm trying to make an Arduino display text on an LCD using I2C (HD44780). So far, I've used arduino-hal from the avr-hal crate (github.com/Rahix/avr-hal) to program the Arduino, and I wonder if anyone happens to know of a library/crate which is compatible with it? So far I've only found ag-lcd which doesn't seem to work with I2C.