read and write in send #2
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src/spi.rs
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| @@ -22,6 +22,7 @@ where | |||
| mosi: Mosi, | |||
| sck: Sck, | |||
| timer: Timer, | |||
| read_val: u8, | |||
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Seems to me that read_val should be Option<u8>, so that read() can return an error if it's called when no data is available. Then read() can be
fn read(&mut self) -> nb::Result<u8, Error> {
if let Some(byte) = self.read_val.take() {
Ok(byte)
} else {
Err(Something)
}
}But I also don't think this is strictly required by the embedded-hal trait, it's just a way to help catch invalid uses of your interface.
src/spi.rs
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| self.read_val = (self.read_val << 1) | 1 | ||
| } else { | ||
| self.read_val = self.read_val << 1 | ||
| } |
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I'm not sure this code is correct in the case where self.mode.phase == CaptureOnSecondTransition. In that case in the original implementation, you have a clock transition before reading the first bit. Here, you immediately read the pin on entry, which may be in an indeterminate state depending on the peripheral to which you're interfacing.
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I think I may be wrong about something here -- I'll try to prove/disprove this problem, and get back to you
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Nope, my comment is correct. Sorry for the confusion
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@austinglaser Try now. |
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LGTM, at least as far as I can tell without actually testing on hardware |
Fixes #1
@austinglaser Please review. Is this a correct implementation now?