TwoWireObject Class Reference

Convenience wrapper binding a TwoWire instance and device address. More...

#include <Wire.h>

Public Member Functions
	TwoWireObject (TwoWire &w, uint8_t addr)
	Construct a TwoWireObject with a specific TwoWire instance.
	TwoWireObject (uint8_t addr)
	Construct a TwoWireObject using the global Wire instance.
void	reset ()
	Reset the I2C system and unhang the bus.
bool	ping ()
	Check to see if the bound device address exists on this bus.
int	writeRegN (uint32_t reg, const uint8_t *buf, uint32_t blen)
	Write a number of 8-bit values to the specified register address.
int	readRegN (uint32_t reg, uint8_t *buf, uint32_t blen)
	Read a number of 8-bit values from the specified register address.
int	writeReg8 (uint32_t reg, uint8_t data)
	Write an 8-bit value to a target device register.
int	readReg8 (uint32_t reg, uint8_t &data)
	Read an 8-bit value from a target device register.

Detailed Description

Convenience wrapper binding a TwoWire instance and device address.

TwoWireObject stores a reference to a TwoWire instance and a fixed 7-bit I2C device address, providing a cleaner API for register-based access to a single device. All methods delegate to the underlying TwoWire, automatically supplying the stored device address.

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Expand for Example Usage

TwoWireObject Example

Example: Using TwoWireObject for Register Access

#include <wire.h>
 
TwoWire Wire;
TwoWireObject Sensor(Wire, 0x68);   // Bind to device at address 0x68
 
void UserMain(void *pd)
{
    Wire.begin();
 
    if (Sensor.ping())
    {
        uint8_t id;
        Sensor.readReg8(0x75, id);     // Read WHO_AM_I register
        iprintf("Device ID: 0x%02X\r\n", id);
 
        Sensor.writeReg8(0x6B, 0x00);  // Wake up device
    }
}

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See also

TwoWire

Constructor & Destructor Documentation

TwoWireObject() [1/2]

TwoWireObject::TwoWireObject ( TwoWire & w, uint8_t addr )

inline

Construct a TwoWireObject with a specific TwoWire instance.

Parameters

w	Reference to the TwoWire instance to use
addr	7-bit I2C device address

TwoWireObject() [2/2]

TwoWireObject::TwoWireObject ( uint8_t addr )

inline

Construct a TwoWireObject using the global Wire instance.

Parameters

addr	7-bit I2C device address

Member Function Documentation

ping()

bool TwoWireObject::ping ( )

inline

Check to see if the bound device address exists on this bus.

Return values

true	if the address exists

readReg8()

int TwoWireObject::readReg8 ( uint32_t reg, uint8_t & data )

inline

Read an 8-bit value from a target device register.

Parameters

reg	Register address to read
data	Reference to variable in which to store the register data

Returns

Wire Result Codes

readRegN()

int TwoWireObject::readRegN ( uint32_t reg, uint8_t * buf, uint32_t blen )

inline

Read a number of 8-bit values from the specified register address.

Parameters

reg	Register address to read
*buf	Pointer to buffer to store received data
blen	Number of bytes to read

Returns

Wire Result Codes

writeReg8()

int TwoWireObject::writeReg8 ( uint32_t reg, uint8_t data )

inline

Write an 8-bit value to a target device register.

Parameters

reg	Register address to write
data	Data to write to register

Returns

Wire Result Codes

writeRegN()

int TwoWireObject::writeRegN ( uint32_t reg, const uint8_t * buf, uint32_t blen )

inline

Write a number of 8-bit values to the specified register address.

Executing this function will send the following: a start bit, the target device address and read/write bit, the 8-bit data bytes, and finally a stop bit. Note that the address is not incremented with each 8-bit data value.

Parameters

reg	Register address to write
*buf	Pointer to buffer containing data to write
blen	Number of bytes to write

Returns

Wire Result Codes

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

• Wire.h