I2C Master Write

Write data to I2C slave device or I2C slave device register

• Library:

• Simulink Support Package for Raspberry Pi Hardware / Communication

• 

Description

Write data to an I2C slave device or an I2C slave device register. Using this block, you can also write data to a specific register on the I2C slave.

For more information on I2C communication, refer to Support I2C Communication and The Raspberry Pi I2C Interface. To open the pin map of the Raspberry Pi board, click the View pin map.

Ports

Input

Data — Input port to write data to I2C slave device or an I2C slave device register

[1xN] and [Nx1] array

The input port write data to the I2C slave device or I2C slave device register.

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

Output

Status — Status of write operation

scalar

Output port to display error status. For more information, see Output error status.

Dependencies

This port appears only when you select the Output error status parameter.

Data Types: uint8

Parameters

Board — Specific board used for I2C communication

Pi 2 Model B (default) | Model B Rev1 | Model B Rev2 | Model B+ | Pi 3 Model B

Select the specific board that you are using. Changing the board updates the pin choices that you get.

Slave address — Address of I2C slave device

10 (default) | scalar

Enter the I2C slave device address to which you want to write the data. The I2C slave device address is a 7-bit address.

Specify this address as an integer or in hexadecimal format by using hex2dec(), for example hex2dec(‘61’).

Slave byte order — Byte order supported by the I2C slave device

BigEndian (default) | LittleEndian

Select the byte ordering that your I2C slave supports.

The two byte ordering options are:

• Big Endian — The most significant byte is written first over the I2C bus. This option is the default option.

• Little Endian — The least significant byte is written first over the I2C bus.

Enable register access — Option to enable writing to the register on I2C slave device

On (default) | Off

Select this check box to write data to a specific I2C slave register.

When you clear this parameter, the Send NACK at the end of data transfer and Remove stop bit at the end of data transfer parameters are displayed. Using these parameters, you can modify the write operation according to your requirements. For more information, I2C Register Read/Write

Slave register address — I2C slave device register address

0 (default) (default) | scalar

Enter the slave device register address to which you want to write the data.

Dependencies

This parameter is enabled only when you select the Enable register access parameter.

Send NACK at the end of data transfer — Option to send Not Acknowledge bit at the end of data transfer

off (default) | on

When you select this parameter, the I2C Master Write block sends a NACK (Not Acknowledge) bit to the slave device with the final byte.

When the slave device receives the NACK, it waits for a STOP condition from the I2C master block. The master block generates either a STOP condition to abort the transfer or a repeated START condition to start a new transfer.

When you clear this parameter, the I2C Master Write block sends an ACK (Acknowledge) bit to the slave device at the end of every byte. The ACK indicates that the I2C Master Write block is ready to read the next byte from the slave device.

Dependencies

This parameter appears only when you clear the Enable register access parameter.

Remove stop bit at the end of data transfer — Option to remove STOP bit at the end of data transfer

off (default) | on

When you clear this parameter, the block sends a STOP condition. This condition indicates that the block has terminated the data transmission and the I2C bus is free for any other I2C master block to initiate the read/write operation.

When you select this parameter, the block sends another START condition followed by an address and read/write bit. The block sends any number of start conditions recursively. Such a repeated START condition allows write operations to the slave devices without releasing the bus. No other master block interrupts the operation.

Dependencies

This parameter appears only when you clear the Enable register access parameter.

Output error status — Option to display output error status

Off (default) | On

Select this option to display the output error status. When you select this parameter, the block configures an output port. The port on the block is labeled as Status, indicating that the block outputs the status of the write operation at the output port.

The block outputs the status as a uint8 value. Each value corresponds to a data transfer status.

Status value	Status description
0	SUCCESS
1	BUSY
2	ARBITRATION_LOST
4	NO_ACKNOWLEDGE
8	BUS_ERROR
16	BUS_NOT_IN_USE