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I2C Class Reference

I2C bus interface class. More...

#include <I2C.h>

Inheritance diagram for I2C:
SensorBase ADXL345_I2C

Public Types

enum  Port { kOnboard, kMXP }
 

Public Member Functions

 I2C (Port port, uint8_t deviceAddress)
 Constructor. More...
 
virtual ~I2C ()
 Destructor.
 
 I2C (const I2C &)=delete
 
I2Coperator= (const I2C &)=delete
 
bool Transaction (uint8_t *dataToSend, uint8_t sendSize, uint8_t *dataReceived, uint8_t receiveSize)
 Generic transaction. More...
 
bool AddressOnly ()
 Attempt to address a device on the I2C bus. More...
 
bool Write (uint8_t registerAddress, uint8_t data)
 Execute a write transaction with the device. More...
 
bool WriteBulk (uint8_t *data, uint8_t count)
 Execute a bulk write transaction with the device. More...
 
bool Read (uint8_t registerAddress, uint8_t count, uint8_t *data)
 Execute a read transaction with the device. More...
 
bool ReadOnly (uint8_t count, uint8_t *buffer)
 Execute a read only transaction with the device. More...
 
void Broadcast (uint8_t registerAddress, uint8_t data)
 Send a broadcast write to all devices on the I2C bus. More...
 
bool VerifySensor (uint8_t registerAddress, uint8_t count, const uint8_t *expected)
 Verify that a device's registers contain expected values. More...
 

Detailed Description

I2C bus interface class.

This class is intended to be used by sensor (and other I2C device) drivers. It probably should not be used directly.

Constructor & Destructor Documentation

I2C::I2C ( Port  port,
uint8_t  deviceAddress 
)

Constructor.

Parameters
portThe I2C port to which the device is connected.
deviceAddressThe address of the device on the I2C bus.

Member Function Documentation

bool I2C::AddressOnly ( )

Attempt to address a device on the I2C bus.

This allows you to figure out if there is a device on the I2C bus that responds to the address specified in the constructor.

Returns
Transfer Aborted... false for success, true for aborted.
void I2C::Broadcast ( uint8_t  registerAddress,
uint8_t  data 
)

Send a broadcast write to all devices on the I2C bus.

This is not currently implemented!

Parameters
registerAddressThe register to write on all devices on the bus.
dataThe value to write to the devices.
bool I2C::Read ( uint8_t  registerAddress,
uint8_t  count,
uint8_t *  buffer 
)

Execute a read transaction with the device.

Read bytes from a device. Most I2C devices will auto-increment the register pointer internally allowing you to read consecutive registers on a device in a single transaction.

Parameters
registerAddressThe register to read first in the transaction.
countThe number of bytes to read in the transaction.
bufferA pointer to the array of bytes to store the data read from the device.
Returns
Transfer Aborted... false for success, true for aborted.
bool I2C::ReadOnly ( uint8_t  count,
uint8_t *  buffer 
)

Execute a read only transaction with the device.

Read bytes from a device. This method does not write any data to prompt the device.

Parameters
bufferA pointer to the array of bytes to store the data read from the device.
countThe number of bytes to read in the transaction.
Returns
Transfer Aborted... false for success, true for aborted.
bool I2C::Transaction ( uint8_t *  dataToSend,
uint8_t  sendSize,
uint8_t *  dataReceived,
uint8_t  receiveSize 
)

Generic transaction.

This is a lower-level interface to the I2C hardware giving you more control over each transaction.

Parameters
dataToSendBuffer of data to send as part of the transaction.
sendSizeNumber of bytes to send as part of the transaction.
dataReceivedBuffer to read data into.
receiveSizeNumber of bytes to read from the device.
Returns
Transfer Aborted... false for success, true for aborted.
bool I2C::VerifySensor ( uint8_t  registerAddress,
uint8_t  count,
const uint8_t *  expected 
)

Verify that a device's registers contain expected values.

Most devices will have a set of registers that contain a known value that can be used to identify them. This allows an I2C device driver to easily verify that the device contains the expected value.

Precondition
The device must support and be configured to use register auto-increment.
Parameters
registerAddressThe base register to start reading from the device.
countThe size of the field to be verified.
expectedA buffer containing the values expected from the device.
bool I2C::Write ( uint8_t  registerAddress,
uint8_t  data 
)

Execute a write transaction with the device.

Write a single byte to a register on a device and wait until the transaction is complete.

Parameters
registerAddressThe address of the register on the device to be written.
dataThe byte to write to the register on the device.
Returns
Transfer Aborted... false for success, true for aborted.
bool I2C::WriteBulk ( uint8_t *  data,
uint8_t  count 
)

Execute a bulk write transaction with the device.

Write multiple bytes to a device and wait until the transaction is complete.

Parameters
dataThe data to write to the register on the device.
countThe number of bytes to be written.
Returns
Transfer Aborted... false for success, true for aborted.

The documentation for this class was generated from the following files: