Elixir is far enough away from hardware that I’m not sure interrupt-driven vs. non-interrupt-driven is going to be the main issue. You can poll GPIOs with elixir_ale or tell elixir_ale to send a message when the GPIO changes. The latter way is “kind of” interrupt-driven since nothing in the system is actively polling the GPIO. There’s a lot of software between the hardware and your Elixir code, so it won’t work as well as you’d expect. I think that it’s passable for event rates under 100 per second.

I’d personally look for a Linux kernel driver for this. Linux kernel drivers just work so much better when dealing with the low-level details of reacting to a GPIO changing and initiating SPI transactions. When the messages are fully received, Elixir makes handling the messages really convenient and is pretty efficient.

Just to add here, there was some work to make a NIF version of elixir_ale. An initial prototype worked really well - it was a couple orders of magnitude faster than elixir_ale. I had been helping someone out on it, but I think they’ve long since lost interest/gotten busy with other things. It would be another option if the kernel driver option won’t work for you and unfinished code doesn’t scare you.

Frank