[SOLVED] I2C in STM32F103 longer data

[aminpix]

I am trying to use PCA9539 as an IOexpander for my project. I have a STM32F103 connected to PCA9539 via I2C.
The problem I have is to write into PCA9539. Based on the datasheet I should to send (1) address (2) command byte (3 and 4) data bytes via I2C. When I check the I2C bus lines with oscilloscope, I see the micro only sends 2 bytes after address byte. i.e. the last byte wont be send.

I use atollic and stm32cubeMX
Here is my code:

  HAL_GPIO_WritePin(GPIOF,I2C2_RST_Pin,'1');
  unsigned char I2C_2_buffer[8];
  I2C_2_buffer[0]=0x00; //command byte
  I2C_2_buffer[1]=0x50;
  I2C_2_buffer[2]=0x55;
  I2C_2_buffer[3]=0x00;

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {

	    /* USER CODE END WHILE */
		  HAL_Delay(4000);
		  HAL_GPIO_TogglePin(GPIOD,LED0_Pin);
  	          HAL_I2C_Master_Transmit(&hi2c2,0x76<<1,I2C_2_buffer,4,1000);
   	          HAL_Delay(1000);

		  
  }

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static void MX_I2C2_Init(void)
{

  /* USER CODE BEGIN I2C2_Init 0 */

  /* USER CODE END I2C2_Init 0 */

  /* USER CODE BEGIN I2C2_Init 1 */

  /* USER CODE END I2C2_Init 1 */
  hi2c2.Instance = I2C2;
  hi2c2.Init.ClockSpeed = 100000;
  hi2c2.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c2.Init.OwnAddress1 = 0;
  hi2c2.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c2.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c2.Init.OwnAddress2 = 0;
  hi2c2.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c2.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  if (HAL_I2C_Init(&hi2c2) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN I2C2_Init 2 */

  /* USER CODE END I2C2_Init 2 */

}

 

[andre_luis]

Did you check the oscilloscope if the slave is sending the acknowledge on the bus?

 

[aminpix]

Yes, The slave sends the ACK.

 

[aminpix]

I figure out what was the problem.
The expected code in the PCA9539 was different that what i have sent.
after sending the proper values it starts to work. Thanks