Embassy Support

[jessebraham]

We made an attempt to implement embassy support today, which unfortunately was not successful. Some tasks which should be completed prior to attempting again are:

• implement the embedded-hal alpha traits
• implement the embedded-hal-async traits
• de-macro the gpio module as much as possible.

[bjoernQ]

Technically de-macro gpio is not strictly required but totally needed - it's a bit messy. I don't have a good solution for that currently.
But definitely e.g. the fix for #55 is pretty unpleasant when dealing with the macros

[bjoernQ]

I created an issue for the GPIO topic: #58

[ewrogers]

Noticed that a couple Embassy examples have shown up in the examples folders, namely embassy_hello_world.rs and embassy_wait.rs. Really exciting!

Is this something that can be used today, or is it still an internal WIP? Would love to help where I can with this, as I recently discovered Embassy and think it's a fantastic framework for Rust embedded.

If so, we may want to consider contributing some examples to the Embassy examples under a new folder like esp32c3 for visibility.

[jessebraham]

These examples are quite new but both should be functional. @MabezDev has been the main driver behind this effort, so big thanks to him 😁

We have Embassy time drivers using either TIMG or SYSTICK (except ESP32) so technically you are able to write Embassy applications as-is. However, we currently only have async drivers for GPIO, so it's quite limited in this respect. We are, however, currently working on more; I believe @MabezDev is working on (or starting) SPI next.

Regarding helping out, adding async drivers would be tremendously helpful. We have a couple tracking issues for this, primarily the first of the two right now:

• Implement the embedded-hal-async Traits once stabilized #70
• Implement async support for all applicable peripheral drivers #361

As we get more drivers we're able to add more interesting examples.

[ewrogers]

Understood, really neat to see it and props to @MabezDev for the effort. So with the ESP32 (all variants) it's required to use TIMG because SYSTICK is unavailable on the platform?

Looks like the effort is to build out drivers for other things like I2C and SPI so it can be used in the Embassy framework.

I am still learning the ropes of Rust + Embedded (and now Embassy/RTOS concepts😬), so it may be a bit of a mountain for me to climb but I am interested for sure. 🐌⛰️

I will take a look and see if I an contribute, namely on the Delay or I2C front if SPI is being worked on next.

[jessebraham]

So with the ESP32 (all variants) it's required to use TIMG because SYSTICK is unavailable on the platform?

Correct, unfortunately this chip did not have the SYSTICK peripheral. All of the ESP32 C-Series and S-Series chips have SYSTICK, however.

Hope your Rust journey goes well, hope to hear from you in the future :)