Support for both embedded-hals (0.2.x and 1.0.0-alpha)

[burrbull]

CountDown, Pwm, Watchdogs traits are not implemented for 1.0.0-alpha due to rust-embedded/embedded-hal#324

Also need help with new spi::blocking traits.

[therealprof]

Nice. This should probably be tested in CI, right?

[burrbull]

cc @ryankurte Could you help with testing?

[pdgilbert]

(newbie question - for my own sanity I really shouldn't be here.)
I've been trying to build some examples with the e-hal branch but I think I'm missing something simple. When I look at the tree almost everything is still using embedded-hal:0.2.6 rather than embedded-hal:1.0.0-alpha.6. I see [dependencies.embedded-hal-one]. Is there something I need to specify?

[burrbull]

This impl uses 1.0.0-alpha.6 for now.
Unfortunately different alpha versions of embedded-hal are not compatible.
So if your driver uses other alpha version, this will not help you. Just use 0.2 with compat and wait for stabilization.

[pdgilbert]

I understand it it is just using 1.0.0-alpha.6, thus my problem with rust-radio-sx127x. That is ok, you should not spend a lot of time trying to support different alpha versions when the idea is to move past alpha. I am wondering how to force it to use 1.0.0-alpha.6 rather than embedded-hal:0.2.6? When I build examples that use only the HAL (like blink) it is using 0.2.6 not 1.0.0-alpha.6 so I cannot see how to use it to test if my code works with 1.0.0, and am not testing if 1.0.0 works.

[pdgilbert]

I think I am slowly starting to understand. It is not just the drivers but I actually have to go through every package, even things like cortex-m and panic-semihosting and specify versions that use embedded-hal:1.0.0-alpha.6 Is that correct?

[burrbull]

No you don't need to change cortex-m.
I tried to update rust-radio-sx127x for alpha6. See https://github.com/burrbull/rust-radio-sx127x/tree/alpha6
But it still blocked by driver-pal dependency. ryankurte/rust-driver-pal#17

Also as I can see driver-pal is testing playground and has inverse optional dependencies. Now supports only linux-embedded-hal and cp2130. So it looks like you need to add f4xx-hal::Spi to driver_pal::HalSpi first.

[ryankurte]

Also as I can see driver-pal is testing playground and has inverse optional dependencies. Now supports only linux-embedded-hal and cp2130. So it looks like you need to add f4xx-hal::Spi to driver_pal::HalSpi first

it is very much an experiment / WIP but, sorta the opposite... the idea was to pull out all the common bounds to simplify driver implementations, then provides opt-in helpers for linux and cp2130 (HalSpi) fulfilling those bounds. it's a bit more complicated than it needs to be at this point, but, such is life with limited hours in the day.

to instantiate the radio driver you just need to call Sx127x::spi with types fulfilling the required bounds (which creates a driver-pal::Wrapper internally). in practice (except for the current conflicting e-h issues) you shouldn't need to touch driver-pal to use the driver.