OneWire support

[David-OConnor]

OneWire is a digital protocol used by a very popular temperature sensor, the DS1820B. I'm unable to get it working with this crate, and am wonder what you think the best approach is.

I'm suspicious this recent issue is related.

I think the issue is that the GPIO pins this library uses are generally input or output only, and don't implement both. Is this correct? The specific issue I'm running into with this OneWire crate is that it expects the pin to implement this:

pub trait OpenDrainOutput<E>: OutputPin<Error = E> + InputPin<Error = E> {}

Is this an issue of implementing both InputPin and OutputPin for gpio pins configured as open drain? I looked through this source file to try to find a solution, either robust, or a hack to make OneWire work, but am not sure how to deal with the macros. Is it just an issue of making a way to configure a pin with both the InputPin and OutputPin methods? Ie set_low() and is_low()? Ie a copy+paste job.

Thoughts? Is this the same thing as the issue I linked near the top?

[teskje]

@David-OConnor I believed this was fixed with merging #114. Can you confirm?

[David-OConnor]

Affirm. Closing!