embvm::i2c Namespace Reference

Definitions, functions, and classes related to I2C communication bus devices. More...

Classes
class	activeMaster
class	master
	This class provides the I2C master interface definition. More...
struct	op_t
	I2C operation definition. More...

Typedefs
using	ao_storage = std::pair< embvm::i2c::op_t, const embvm::i2c::master::cb_t >
using	addr_t = uint8_t
	I2C address storage type. More...
using	commBus = commBus< i2c::op_t, i2c::baud, i2c::I2C_MASTER_REQD_STATIC_FUNCTION_SIZE, i2c::status >
	Convenience alias for the declaration of the I2C commBus. More...

Enumerations
enum	operation : uint8_t {   operation::stop = 0, operation::restart, operation::write, operation::read,   operation::writeRead, operation::writeNoStop, operation::continueWriteNoStop, operation::continueWriteStop,   operation::ping }
	I2C operation types. More...
enum	state : uint8_t { state::idle = 0, state::busy, state::error }
	Represents the state of the I2C bus. More...
enum	status {   status::ok = 0, status::enqueued, status::busy, status::error,   status::unknown, status::addrNACK, status::dataNACK, status::bus }
	I2C bus status. More...
enum	baud { baud::lowSpeed = 10000, baud::standard = 100000, baud::fast = 400000 }
	Valid I2C bus baudrate options. More...
enum	pullups : uint8_t { pullups::external = 0, pullups::internal }
	Pull-up configuration options for an I2C master device. More...

Variables
static constexpr size_t	I2C_MASTER_REQD_STATIC_FUNCTION_SIZE = 96
	Maximum size of the I2C master callback functor object. More...
static constexpr uint8_t	ReadBit = 0x01
	Added to slave address to indicate a read command. More...

Detailed Description

Definitions, functions, and classes related to I2C communication bus devices.

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Class Documentation

embvm::i2c::op_t

struct embvm::i2c::op_t

I2C operation definition.

The I2C bus operates in half-duplex mode, meaning that reads and writes do not occur simultaneously. The operation type represents a variety of operations which can be performed by an I2C device. The transmit options (tx_buffer and tx_size) are required by any operations using "write". The receive options (rx_buffer and rx_size) are required by any operations using "read".

Class Members
uint8_t	address	Slave device address (7-bit).
operation	op	Operation to perform.
uint8_t *	rx_buffer	Pointer to the receive buffer. Does not need to be specified for write-only commands.
size_t	rx_size	Number of bytes to receive. Does not need to be specified for write-only commands.
const uint8_t *	tx_buffer	Pointer to the transmit buffer. Does not need to be specified for read-only commands.
size_t	tx_size	Number of bytes to transmit. Does not need to be specified for read-only commands.

Typedef Documentation

addr_t

using embvm::i2c::addr_t = typedef uint8_t

I2C address storage type.

ao_storage

using embvm::i2c::ao_storage = typedef std::pair<embvm::i2c::op_t, const embvm::i2c::master::cb_t>

commBus

using embvm::i2c::commBus = typedef commBus<i2c::op_t, i2c::baud, i2c::I2C_MASTER_REQD_STATIC_FUNCTION_SIZE, i2c::status>

Convenience alias for the declaration of the I2C commBus.

Enumeration Type Documentation

baud

enum embvm::i2c::baud

strong

Valid I2C bus baudrate options.

Numeric values are in Hz.

Enumerator
lowSpeed
standard
fast

operation

enum embvm::i2c::operation : uint8_t

strong

I2C operation types.

The operation enum defines the type of transfer that the op_t structure is to perform.

Enumerator
stop
restart	Generate a stop condition.
write	Generate a bus restart. Write to slave Performs the following sequence: start - address - write - stop
read	Read from slave Performs the following sequence: start - address - read - stop.
writeRead	write to slave and then read from slave Performs the following sequence: start - address - write - restart - address - read - stop
writeNoStop	start a write to the slave and but do not issue a stop Performs the following sequence: start - address - write
continueWriteNoStop	continue a write to the slave and do not stop the transaction Performs the following sequence: write
continueWriteStop	continue a write to the slave and then stop the transaction Performs the following sequence: write - stop
ping	Send only address to see if there is an ACK Performs the following sequence: start - address.

pullups

enum embvm::i2c::pullups : uint8_t

strong

Pull-up configuration options for an I2C master device.

Enumerator
external	External pullups exist for SDA and SCL.
internal	Use internal pull-ups on SDA and SCL (if supported by the device).

state

enum embvm::i2c::state : uint8_t

strong

Represents the state of the I2C bus.

Enumerator
idle	The bus is idle and ready to receive work.
busy	The bus is currently busy executing a transaction.
error	A bus error occurred and needs to be corrected.

status

enum embvm::i2c::status

strong

I2C bus status.

This enumeration represents the status of an I2C bus. This type extends the default embvm::comm::status definition with additional I2C-specific statuses.

Enumerator
ok	The operation completed successfully.
enqueued	The operation was enqueued for later processing.
busy	The device cannot handle the request at this time; try again.
error	An error occurred with this transaction.
unknown	The success/failure status of the transaction could not be determined.
addrNACK	Addr was transmitted, NACK received.
dataNACK	Data was transmitted, NACK received.
bus	Bus error, such as missing start/stop condition.

Variable Documentation

I2C_MASTER_REQD_STATIC_FUNCTION_SIZE

constexpr size_t embvm::i2c::I2C_MASTER_REQD_STATIC_FUNCTION_SIZE = 96

static

Maximum size of the I2C master callback functor object.

ReadBit

constexpr uint8_t embvm::i2c::ReadBit = 0x01

static

Added to slave address to indicate a read command.