Trait embedded_hal::spi::SpiDevice

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pub trait SpiDevice<Word: Copy + 'static = u8>: ErrorType {
    // Required method
    fn transaction(
        &mut self,
        operations: &mut [Operation<'_, Word>],
    ) -> Result<(), Self::Error>;

    // Provided methods
    fn read(&mut self, buf: &mut [Word]) -> Result<(), Self::Error> { ... }
    fn write(&mut self, buf: &[Word]) -> Result<(), Self::Error> { ... }
    fn transfer(
        &mut self,
        read: &mut [Word],
        write: &[Word],
    ) -> Result<(), Self::Error> { ... }
    fn transfer_in_place(&mut self, buf: &mut [Word]) -> Result<(), Self::Error> { ... }
}
Expand description

SPI device trait

SpiDevice represents ownership over a single SPI device on a (possibly shared) bus, selected with a CS (Chip Select) pin.

See the module-level documentation for important usage information.

Required Methods§

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fn transaction( &mut self, operations: &mut [Operation<'_, Word>], ) -> Result<(), Self::Error>

Perform a transaction against the device.

  • Locks the bus
  • Asserts the CS (Chip Select) pin.
  • Performs all the operations.
  • Flushes the bus.
  • Deasserts the CS pin.
  • Unlocks the bus.

The locking mechanism is implementation-defined. The only requirement is it must prevent two transactions from executing concurrently against the same bus. Examples of implementations are: critical sections, blocking mutexes, returning an error or panicking if the bus is already busy.

On bus errors the implementation should try to deassert CS. If an error occurs while deasserting CS the bus error should take priority as the return value.

Provided Methods§

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fn read(&mut self, buf: &mut [Word]) -> Result<(), Self::Error>

Do a read within a transaction.

This is a convenience method equivalent to device.transaction(&mut [Operation::Read(buf)]).

See also: SpiDevice::transaction, SpiBus::read

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fn write(&mut self, buf: &[Word]) -> Result<(), Self::Error>

Do a write within a transaction.

This is a convenience method equivalent to device.transaction(&mut [Operation::Write(buf)]).

See also: SpiDevice::transaction, SpiBus::write

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fn transfer( &mut self, read: &mut [Word], write: &[Word], ) -> Result<(), Self::Error>

Do a transfer within a transaction.

This is a convenience method equivalent to device.transaction(&mut [Operation::Transfer(read, write)].

See also: SpiDevice::transaction, SpiBus::transfer

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fn transfer_in_place(&mut self, buf: &mut [Word]) -> Result<(), Self::Error>

Do an in-place transfer within a transaction.

This is a convenience method equivalent to device.transaction(&mut [Operation::TransferInPlace(buf)].

See also: SpiDevice::transaction, SpiBus::transfer_in_place

Implementations on Foreign Types§

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impl<Word: Copy + 'static, T: SpiDevice<Word>> SpiDevice<Word> for &mut T

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fn transaction( &mut self, operations: &mut [Operation<'_, Word>], ) -> Result<(), Self::Error>

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fn read(&mut self, buf: &mut [Word]) -> Result<(), Self::Error>

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fn write(&mut self, buf: &[Word]) -> Result<(), Self::Error>

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fn transfer( &mut self, read: &mut [Word], write: &[Word], ) -> Result<(), Self::Error>

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fn transfer_in_place(&mut self, buf: &mut [Word]) -> Result<(), Self::Error>

Implementors§