read

R2026b

Read from I2C device connected to NVIDIA Jetson board

Since R2026a

Syntax

data = read(i2cObj)

data = read(i2cObj,count)

data = read(i2cObj,count,dataPrecision)

Description

Add-On Required: This feature requires the MATLAB Coder Support Package for NVIDIA Jetson and NVIDIA DRIVE Platforms add-on.

data = read(i2cObj) returns a single uint8 value from the I2C device represented by i2cObj.

data = read(i2cObj,count) reads the number of uint8 values specified by count from the I2C device.

data = read(i2cObj,count,dataPrecision) reads the value as the data type dataPrecision.

Examples

Read from I2C Device

Create a jetson object named hwObj, and scan the I2C buses on the Jetson™ hardware by using the scanI2CBus function. In this example, the Jetson board has two I2C buses, i2c-1 and i2c-8. Each bus has a device at address 0x74.

hwObj = jetson;
addresses = scanI2CBus(hwObj);
addresses{:}

ans = 

  struct with fields:

        Bus: 'i2c-1'
    Devices: {'74'}


ans = 

  struct with fields:

        Bus: 'i2c-8'
    Devices: {'74'}

Create an i2cdev object, i2cObj, connecting to the device on the i2c-1 bus.

i2cObj = i2cdev(hwObj,"i2c-1",0x74);

Read 9 elements from the I2C device. By default, the read function reads the elements as the uint8 data type.

out2 = read(i2cObj,9)

out2 =

  1×9 uint8 row vector

    0    0    0    0    0    0    0    0   89

Read 5 elements from the I2C device. Specify the dataPrecision as "uint32" to read the data as the uint32 data type.

out2 = read(i2cObj,5,"uint32")

out2 =

  1×5 uint32 row vector

    0    0   89    0    0

Input Arguments

i2cObj — Connection to I2C device

i2cdev object

Connection to the I2C device, specified as an i2cdev object.

count — Number of elements to read

1 (default) | positive integer

Number of elements to read from the I2C device, specified as a positive integer.

dataPrecision — Data type

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

Data type, specified as "uint8", "int8", "uint16", "int16", "uint32", "int32", "uint64", or "int64".

Output Arguments

data — Data read from I2C device

scalar | vector

Data read from I2C device, returned as a scalar or vector. The count argument determines the length of the output data, and the dataPrecision argument determines the data type of the output data.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Version History

Introduced in R2026a

R2026b: Code generation support

You can generate C, C++, or CUDA^® code from the read function.