如何使用STM32 HAL I2C从PCT2075获取温度

Question

I would like to get a temperature from PCT2075 by using STM32 HAL I2C. Only I can see that HAL ERROR status even I'm using HAL_I2C_Mem_Read() fucntion.

Also I'm confusing what can I use for slave address. In data sheet, slave address is 1001 000. Then I should write a slave address as 0x48 or (0x48<<1)?

I have another question. When I configure GPIO pins in I2C as PULLUP, it is don't need to put PUll up resistor in the circuit?. I know that there are internal pullup resistor in GPIOS pins.

Lastly, Should I send to configure data to slave before getting a Temperature. https://www.nxp.com/docs/en/data-sheet/PCT2075.pdf To be honest, I dont know how to read a datasheet exactly.

static void MX_I2C1_Init(void)
{
  /* USER CODE END I2C1_Init 1 */
  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 400000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 0x48;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  if (HAL_I2C_Init(&hi2c1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN I2C1_Init 2 */

  /* USER CODE END I2C1_Init 2 */
}

main()
{
retVal = HAL_I2C_Master_Transmit(&hi2c1, slave_addr, &send, I2C_MEMADD_SIZE_8BIT, 500);

retVal = HAL_I2C_Mem_Read(&hi2c1, slave_addr, 0x00u, I2C_MEMADD_SIZE_16BIT, &TempReadBuffer[0], 16, 500);
retVal = HAL_I2C_Mem_Read(&hi2c1, slave_addr, 0x00u, I2C_MEMADD_SIZE_16BIT, &TempReadBuffer[0], 16, 500);
}

retVal = HALL_ERROR

Answer 1

Follow the figure 12 in the datasheet.

1) First send slave address with 0 (for write operation). Slave address becomes 1001 000 0

2) Send the Pointer address - For temperature it is 0000 0000.(See Page 10)

3) The again send slave address with 1 meaning read operation. Slave address becomes 1001 000 1

4) Now you can read from the temperature register of the device.