Cannot get I2C to work

[wfd]

Greetings,

I am trying to read register 0x00 through 0x0F on an I2C enabled Chip (Si4703) I have got the reset set up and working but my I2C is not working as I am unfamiliar with the HAL protocols 

I have created a number of variable pointers to store data

/* USER CODE BEGIN PV */
int16_t *DeviceID_ptr;
int16_t *ChipID_ptr;
int16_t *PowerCFG_ptr;
int16_t *Channel_ptr;
int16_t *SYSConfig1_ptr;
int16_t *SYSConfig2_ptr;
int16_t *ReadChan_ptr;
int16_t *StatusRSSI_ptr;
/* USER CODE END PV */

Fruther on in the main loop I am trying to get to read the data at just register 0x00

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

	  buf[0] = DeviceID_ptr;
      /* USER CODE END WHILE */
  	  // pass buffer as a character pointer

  	  //strcpy((char*)buf, "Hello!\r\n");
  	  //HAL_UART_Transmit(&hlpuart1, buf, strlen((char*)buf), HAL_MAX_DELAY);
  	  //HAL_Delay(1000);
  	  // save return values of errors
  	  // transmit I2C values
  	  ret = HAL_I2C_Master_Transmit(&hi2c2, SI4703_ADR, DeviceID_ptr, 1, HAL_MAX_DELAY );
  	  if(ret != HAL_OK){
			  strcpy((char*)buf, "Error_Tx\r\n");
		  }
  	  else
  	  {
  		ret = HAL_I2C_Master_Receive(&hi2c2, SI4703_ADR, DeviceID_ptr, 2, HAL_MAX_DELAY );
  		if(ret != HAL_OK){
  		  	 strcpy((char*)buf, "Error_Tx\r\n");
  		}

  	  }

I am getting a lot of very weird errors I think my pointers are screwed up

Thanks for your help

W Dussault

University of Wisconsin Milwaukee

[Foued_KH · Accepted solution]

Hello @wfd , 

It's recommended to use the HAL_I2C_Mem_Read() function : 

HAL_I2C_Mem_Read(&hi2c1, uint16_t DevAddress , uint16_t MemAddress, uint16_t MemAddSize, uint8_t *pData , uint16_t Size, 1uint32_t Timeout);

• uint16_t DevAddress: The 7-bit slave device address.

• uint16_t MemAddress: The memory address to read from on the slave device. This can be a 16-bit value if the slave device supports 16-bit addressing.

• uint16_t MemAddSize: The size of the memory address. This can be either I2C_MEMADD_SIZE_8BIT or I2C_MEMADD_SIZE_16BIT.

• uint8_t *pData: A pointer to the buffer where the read data will be stored.

• uint16_t Size: The number of bytes to read from the slave device.

• uint32_t Timeout: The timeout value in milliseconds.

Foued