I2C with repeated start condition example

[DS.4]

HI

Got an I2C device connected to my p nucleo wb 55 board. currently no luck communicating.

I've been instructed to to use a  repeated start condition in I2C   https://www.i2c-bus.org/repeated-start-condition/

Not sure if my current   HAL functions work for an I2C repeated start condition device? they are :

HAL_I2C_Mem_Write XXX

HAL_I2C_Master_Transmit XXX 

Any other example I can use ?

need to achieve this :

S start

R restart

THNAKS

[Saket_Om]

Hello @DS.4 

To achieve a repeated start condition with your I2C device, you will need to use specific HAL functions that support repeated start conditions. The functions you mentioned (HAL_I2C_Mem_Write and HAL_I2C_Master_Transmit) do not support repeated start conditions.

For repeated start conditions, you should use the following HAL functions:

• HAL_I2C_Master_Sequential_Transmit_IT
• HAL_I2C_Master_Sequential_Receive_IT

These functions are designed to handle sequential transmit and receive operations, which include the capability to perform repeated start conditions.

Please refer to these examples for farther more details:

• Projects/P-NUCLEO-WB55.Nucleo/Examples/I2C/I2C_TwoBoards_RestartComIT
• Projects/P-NUCLEO-WB55.Nucleo/Examples/I2C/I2C_TwoBoards_RestartAdvComIT