writeRegister

R2026b

Write data to I2C device registers

Syntax

writeRegister(dev,register,dataIn)

writeRegister(dev,register,dataIn,precision)

Description

Add-On Required: This feature requires the MATLAB Support Package for Arduino Hardware add-on.

writeRegister(dev,register,dataIn) writes data to the I2C device register.

writeRegister(dev,register,dataIn,precision) also specifies the data precision.

Examples

Write to an I2C Device Register

Create an Arduino object and attach an I2C device object to it.

a = arduino('COM9','Uno','Libraries','I2C');

Use an address to create the I2C device connection.

dev = device(a,'I2CAddress','0x55');

Write value 10 to the I2C device register at address 20.

writeRegister(dev,20,10);

Specify Precision of Data to Write to an I2C Register

Create an Arduino object and attach an I2C device object to it.

a = arduino('COM9','Uno','Libraries','I2C');

Use an address to create the I2C device connection.

dev = device(a,'I2CAddress','0x55');

Write value 10 to the I2C device register at address 20 with the precision of uint16.

writeRegister(dev,20,10,'uint16');

Input Arguments

dev — I2C device connection

device object

I2C device connection, specified as a device object.

register — Address of I2C device register

scalar integer from 0 through 255 | hexadecimal | binary

Address of the I2C device register, specified as a scalar integer from 0 through 255, hexadecimal, or binary.

dataIn — Data to write

scalar | vector

Data to write, specified as a scalar, vector, hexadecimal, or binary. The range of the values in the array is based on the precision.

precision — Data precision

'uint8' (default) | 'int8' | 'uint16' | 'int16' | 'uint32' | 'int32' | 'uint64' | 'int64'

Data precision, specified as one of the following character vectors:

• 'uint8'

• 'int8'

• 'uint16'

• 'int16'

• 'uint32'

• 'int32'

• 'uint64'

• 'int64'

Data can be also be specified in the following formats:

• hexadecimal

• binary

• char

• string

More About

Code Generation Using MATLAB Function Block

• Use writeRegister in a MATLAB^® Function block with the Simulink^® Support Package for Arduino^® Hardware to generate code that can be deployed on Arduino Hardware.

• Values of dataIn is not validated against the precision. The dataIn values will be saturated when it goes beyond the range of the specified precision.

Alternative Functionality

App

Use Arduino Explorer to configure the I2C peripherals and write data to I2C device register. You can use the app in the installed version of MATLAB and MATLAB Online™. For more information, see Connect to I2C Device Using Arduino Explorer App.

Version History

Introduced in R2014b