I2C Master Read

Read data from I2C slave device or I2C slave device register

• Library:

• UAV Toolbox Support Package for PX4 Autopilots

• 

Description

The I2C Master Read block reads serial data from an I2C slave device that is connected to the board. Using this block, you can read data from a specific register on the I2C slave device.

To view the mapping between the Bus number and the port label on hardware board, click View I2C Bus map. For more information on the Bus mapping, see I2C Bus Port Numbers for Labels on PX4 Autopilots.

Ports

Output

Data — Data from I2C slave device

vector

The port reads vector data from an I2C device that is connected to the board. The size of the data is the value that you specify in the Data size parameter.

Data Types: int8 | uint8 | int16 | uint16 | int32 | uint32 | int64 | uint64 | single | double

Status — Status of read operation

scalar

When you select the Output error status parameter, an output port, labeled as Status, becomes available.

The port outputs one of these values:

• 0 for a successful read operation.

• 1 for a failure in opening the bus.

• 2 for a failure in read operation.

Data Types: uint8

Parameters

I2C Bus — I2C bus to read data

1 (default)

Specify the I2C bus on the board to read data from the I2C slave device.

Slave address — I2C register slave address from which to read data

10 (default) | nonnegative integer

Specify the I2C slave address to read the data. You can specify this address in hexadecimal format hex2dec(), for example, 0x20.

Slave byte order — Byte ordering that your I2C slave device supports

BigEndian (default) | LittleEndian

The 2-byte ordering options are:

• BigEndian -The most significant byte is sent first over the I2C bus.

• LittleEndian - The least significant byte is sent first over the I2C bus.

Enable register access — Option to read from a specific I2C slave register

on (default) | off

When you select this parameter, the block reads data from the I2C slave register that you specify in the Slave register address parameter.

Slave register address — The I2C slave register address to read data

2 (default) | integer between 0 and 255

Specify the I2C register address to read the data.

Specify this address as an integer or in hexadecimal format by using hex2dec(), for example, 0x20.

Dependencies

To enable this parameter, select the Enable register access parameter.

Data type — Data type of data from I2C slave device

uint8 (default) | int8 | int16 | uint16 | int32 | uint32 | single | double

Select the data type in which you want to read from the I2C slave device.

Data size (N) — Data size to read from I2C slave device

1 (default) | nonnegative integer

Specify the data size that you want to read from the I2C slave device for the selected data type.

Output error status — Option to display the error status during data transmission

off (default) | on

When you select this parameter, an output port, labeled as Status, becomes available.

The port outputs one of these values:

• 0 for a successful read operation.

• 1 for a failure in opening bus.

• 0 for a failure in read or write operation.

Sample time — Frequency to read data from the I2C slave device

0.01 (default)

Specify how often the I2C Master Read block reads data from the I2C slave device. When you specify this parameter as -1, the block inherits its sample time based on the context of the block within the model.