Trait I2c

pub trait I2c<A: AddressMode = SevenBitAddress>: ErrorType {
    // Required method
    async fn transaction(
        &mut self,
        address: A,
        operations: &mut [Operation<'_>],
    ) -> Result<(), Self::Error>;

    // Provided methods
    async fn read(
        &mut self,
        address: A,
        read: &mut [u8],
    ) -> Result<(), Self::Error> { ... }
    async fn write(
        &mut self,
        address: A,
        write: &[u8],
    ) -> Result<(), Self::Error> { ... }
    async fn write_read(
        &mut self,
        address: A,
        write: &[u8],
        read: &mut [u8],
    ) -> Result<(), Self::Error> { ... }
}

Async I2c.

Required Methods

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

Execute the provided operations on the I2C bus as a single transaction.

Transaction contract:

• Before executing the first operation an ST is sent automatically. This is followed by SAD+R/W as appropriate.

• Data from adjacent operations of the same type are sent after each other without an SP or SR.

• Between adjacent operations of a different type an SR and SAD+R/W is sent.

• After executing the last operation an SP is sent automatically.

• If the last operation is a Read the master does not send an acknowledge for the last byte.

• ST = start condition

• SAD+R/W = slave address followed by bit 1 to indicate reading or 0 to indicate writing

• SR = repeated start condition

• SP = stop condition

Provided Methods

async fn read(&mut self, address: A, read: &mut [u8]) -> Result<(), Self::Error>

Reads enough bytes from slave with address to fill buffer.

I2C Events (contract)

Master: ST SAD+R        MAK    MAK ...    NMAK SP
Slave:           SAK B0     B1     ... BN

Where

• ST = start condition
• SAD+R = slave address followed by bit 1 to indicate reading
• SAK = slave acknowledge
• Bi = ith byte of data
• MAK = master acknowledge
• NMAK = master no acknowledge
• SP = stop condition

async fn write(&mut self, address: A, write: &[u8]) -> Result<(), Self::Error>

Writes bytes to slave with address address.

I2C Events (contract)

Master: ST SAD+W     B0     B1     ... BN     SP
Slave:           SAK    SAK    SAK ...    SAK

Where

• ST = start condition
• SAD+W = slave address followed by bit 0 to indicate writing
• SAK = slave acknowledge
• Bi = ith byte of data
• SP = stop condition

async fn write_read( &mut self, address: A, write: &[u8], read: &mut [u8], ) -> Result<(), Self::Error>

Writes bytes to slave with address address and then reads enough bytes to fill read in a single transaction.

I2C Events (contract)

Master: ST SAD+W     O0     O1     ... OM     SR SAD+R        MAK    MAK ...    NMAK SP
Slave:           SAK    SAK    SAK ...    SAK          SAK I0     I1     ... IN

Where

• ST = start condition
• SAD+W = slave address followed by bit 0 to indicate writing
• SAK = slave acknowledge
• Oi = ith outgoing byte of data
• SR = repeated start condition
• SAD+R = slave address followed by bit 1 to indicate reading
• Ii = ith incoming byte of data
• MAK = master acknowledge
• NMAK = master no acknowledge
• SP = stop condition

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<A: AddressMode, T: I2c<A> + ?Sized> I2c<A> for &mut T

async fn read(&mut self, address: A, read: &mut [u8]) -> Result<(), Self::Error>

async fn write(&mut self, address: A, write: &[u8]) -> Result<(), Self::Error>

async fn write_read( &mut self, address: A, write: &[u8], read: &mut [u8], ) -> Result<(), Self::Error>

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

Implementors