I2C Functions

Namespaces
namespace	hal
	WPILib Hardware Abstraction Layer (HAL) namespace.

Enumerations
enum	HAL_I2CPort : int32_t { HAL_I2C_kInvalid = -1 , HAL_I2C_kOnboard , HAL_I2C_kMXP }

Functions
void	HAL_InitializeI2C (HAL_I2CPort port, int32_t *status)
	Initializes the I2C port. More...
int32_t	HAL_TransactionI2C (HAL_I2CPort port, int32_t deviceAddress, const uint8_t *dataToSend, int32_t sendSize, uint8_t *dataReceived, int32_t receiveSize)
	Generic I2C read/write transaction. More...
int32_t	HAL_WriteI2C (HAL_I2CPort port, int32_t deviceAddress, const uint8_t *dataToSend, int32_t sendSize)
	Executes a write transaction with the device. More...
int32_t	HAL_ReadI2C (HAL_I2CPort port, int32_t deviceAddress, uint8_t *buffer, int32_t count)
	Executes a read transaction with the device. More...
void	HAL_CloseI2C (HAL_I2CPort port)
	Closes an I2C port. More...

Detailed Description

Enumeration Type Documentation

HAL_I2CPort

enum HAL_I2CPort : int32_t

Enumerator
HAL_I2C_kInvalid
HAL_I2C_kOnboard
HAL_I2C_kMXP

Function Documentation

HAL_CloseI2C()

void HAL_CloseI2C

(

HAL_I2CPort

port

)

Closes an I2C port.

Parameters

port	The I2C port, 0 for the on-board, 1 for the MXP.

HAL_InitializeI2C()

void HAL_InitializeI2C	(	HAL_I2CPort	port,
		int32_t *	status
	)

Initializes the I2C port.

Opens the port if necessary and saves the handle. If opening the MXP port, also sets up the channel functions appropriately.

Parameters

[in]	port	The port to open, 0 for the on-board, 1 for the MXP.
[out]	status	Error status variable. 0 on success.

HAL_ReadI2C()

int32_t HAL_ReadI2C	(	HAL_I2CPort	port,
		int32_t	deviceAddress,
		uint8_t *	buffer,
		int32_t	count
	)

Executes a read transaction with the device.

Reads 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

port	The I2C port, 0 for the on-board, 1 for the MXP.
deviceAddress	The register to read first in the transaction.
count	The number of bytes to read in the transaction.
buffer	A pointer to the array of bytes to store the data read from the device.

Returns

>= 0 on success or -1 on transfer abort.

HAL_TransactionI2C()

int32_t HAL_TransactionI2C	(	HAL_I2CPort	port,
		int32_t	deviceAddress,
		const uint8_t *	dataToSend,
		int32_t	sendSize,
		uint8_t *	dataReceived,
		int32_t	receiveSize
	)

Generic I2C read/write transaction.

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

Parameters

port	The I2C port, 0 for the on-board, 1 for the MXP.
deviceAddress	The address of the register on the device to be read/written.
dataToSend	Buffer of data to send as part of the transaction.
sendSize	Number of bytes to send as part of the transaction.
dataReceived	Buffer to read data into.
receiveSize	Number of bytes to read from the device.

Returns

>= 0 on success or -1 on transfer abort.

HAL_WriteI2C()

int32_t HAL_WriteI2C	(	HAL_I2CPort	port,
		int32_t	deviceAddress,
		const uint8_t *	dataToSend,
		int32_t	sendSize
	)

Executes a write transaction with the device.

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

Parameters

port	The I2C port, 0 for the on-board, 1 for the MXP.
deviceAddress	The address of the register on the device to be written.
dataToSend	The byte to write to the register on the device.
sendSize	Number of bytes to send.

Returns

>= 0 on success or -1 on transfer abort.