I2c Class Reference

Detailed Description

This file defines the I2c interface for libmraa

    mraa::I2c* i2c;
    i2c = new mraa::I2c(0);

    i2c->address(HMC5883L_I2C_ADDR);
    rx_tx_buf[0] = HMC5883L_CONF_REG_B;
    rx_tx_buf[1] = GA_1_3_REG;
    i2c->write(rx_tx_buf, 2);

Public Member Functions
	I2c (int bus, bool raw=false)
	~I2c ()
mraa_result_t	frequency (int hz)
mraa_result_t	address (int address)
unsigned char	read ()
int	read (char *data, size_t length)
std::string	read (size_t length)
mraa_result_t	write (char *data, size_t length)
mraa_result_t	writeReg (char reg, char data)
mraa_result_t	write (char data)

Constructor & Destructor Documentation

I2c ( int  bus, bool  raw = false  )

inline

Instantiates an i2c bus. Multiple instances of the same bus can exist and the bus is not guarranteed to be on the correct address before read/write.

Parameters

bus	The i2c bus to use
raw	Whether to disable pinmapper for your board

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~I2c ( )

inline

Closes the I2c Bus used. This does not guarrantee the bus will not be usable by anyone else or communicates this disconnect to any slaves.

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Member Function Documentation

mraa_result_t frequency ( int  hz )

inline

Sets the i2c Frequency for communication. Your board may not support the set frequency. Anyone can change this at any time and this will affect every slave on the bus

Parameters

hz	Frequency to set the bus to in hz

Returns

Result of operation

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mraa_result_t address ( int  address )

inline

Set the slave to talk to, typically called before every read/write operation

Parameters

address

Communicate to the i2c slave on this address

Returns

Result of operation

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unsigned char read ( )

inline

Read exactly one byte from the bus

Returns

char read from the bus

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int read ( char *  data, size_t  length  )

inline

Read mutliple bytes from the bus

Parameters

data	Buffer to write into
length	Size of read

Returns

length of the read or 0 if failed

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std::string read ( size_t  length )

inline

Read length bytes from the bus, and return as a std::string note that this is not a null terminated string

Parameters

length

Size of read to make

Returns

pointer to std::string

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mraa_result_t write ( char *  data, size_t  length  )

inline

Write one byte to the bus

Parameters

data	Buffer to send on the bus
length	Size of buffer to send

Returns

Result of operation

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mraa_result_t writeReg ( char  reg, char  data  )

inline

Write to an i2c register

Parameters

reg	Register to write to
data	Value to write to register

Returns

Result of operation

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mraa_result_t write ( char  data )

inline

Write multiple bytes to the bus

Parameters

data	The byte to send on the bus

Returns

Result of operation

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

• /var/lib/jenkins/workspace/mraa-doc/api/mraa/i2c.hpp