VEML6075 reading value with STM32 HAL library

[ninjagreg]

Dear all,

I am using VEML6075 with a NUCLEO board F030R8 using HAL Library to drive the sensor and i am facing a misterious issue:
I am looping ID, UVB, UVA, UVD, UCOMP1, UCOMP2 data reading ( with a previous initialing configuration register of 01000000 (0x40) ) with a 5 sec pause between each reading sequence.
The thing is that i read for each register the exact same value (!?) ID = UVB = UVA = UVD = UCOMP1 = UCOMP2.

I have followed the reading sequence as :
I2C write: slave address (read/write bit to 0) followed by the command code corresponding to the register code.
I2C read: slave address (read/write bit to 1) followed by a reading of the 2 bytes of the sensor.

Here is the oscilloscope screenshots...

ID register reading (0x0C) whose the value read is 93

UVB register reading (0x09) whose the value read is 93

UVA register reading (0x7) whose the value read is 93

...and i don't think that the rest is nessary to show..
So, i guess there is something i do wrongly. Could you help please?
You ll find below the piece of code i used:

/* USER CODE BEGIN PFP */
 static const uint8_t VEML6075_ADDR = 0x10 << 1; // Use 8-bit address
 static const uint8_t REG_ID = 0x0C ;
 static const uint8_t REG_UVB = 0x09 ;
 static const uint8_t REG_UVA = 0x07 ;
 static const uint8_t REG_DARK_CURRENT = 0x08 ;
 static const uint8_t REG_VISIBLE_LIGHT = 0x0A ;
 static const uint8_t REG_IR_LIGHT = 0x0B ;
 static const uint8_t REG_UV_CONF = 0x00 ;
 static const uint8_t UV_CONF_DATA_BYTE_HIGH= 0x00 ;
 static const uint8_t UV_CONF_DATA_BYTE_LOW = 0x40 ; 

  buf[0] = REG_UV_CONF ; // register adresse for module configuration
   buf[1] = UV_CONF_DATA_BYTE_LOW ; // Data byte low for module configuration
   buf[2] = UV_CONF_DATA_BYTE_HIGH ; // Data byte high for module configuration
   ret = HAL_I2C_Master_Transmit(&hi2c1, VEML6075_ADDR , buf, 3, HAL_MAX_DELAY);  
   if ( ret != HAL_OK ) {
      strcpy((char*)buf, "Error Tx\r\n");
   }

while (1)
  {   
    // Reading of the ID register of the VEML6075 sensor  
    buf[0] = REG_ID ;  
    // Send the Sensor I2C Address follow by the ID command register 
    ret = HAL_I2C_Master_Transmit(&hi2c1, VEML6075_ADDR , buf, 1, HAL_MAX_DELAY);  
    if ( ret != HAL_OK ) {
      strcpy((char*)buf, "Error Tx\r\n");
    } else {  
      // Read 2 bytes from the VEML6075 ID register
      ret = HAL_I2C_Master_Receive(&hi2c1, VEML6075_ADDR, buf, 2, HAL_MAX_DELAY);
      if ( ret != HAL_OK ) {
        strcpy((char*)buf, "Error Rx\r\n");
      } else {
   //Combine the bytes of the ID register to print by UART com
      val = ((int16_t)buf[1] << 8) | (buf[0] );  
      sprintf((char*)buf,
              "%u ID et ",
              ((unsigned int)val));     
      }  
   }      
   HAL_UART_Transmit(&huart2, buf, strlen((char*)buf), HAL_MAX_DELAY); 

  // Reading of the UVB register of the VEML6075 sensor  
   buf[0] = REG_UVB ;  
   ret = HAL_I2C_Master_Transmit(&hi2c1, VEML6075_ADDR , buf, 1, HAL_MAX_DELAY);  
   if ( ret != HAL_OK ) {
      strcpy((char*)buf, "Error Tx\r\n");
   } else {  
   // Read 2 bytes from the VEML6075 UVB register
      ret = HAL_I2C_Master_Receive(&hi2c1, VEML6075_ADDR, buf, 2, HAL_MAX_DELAY);
      if ( ret != HAL_OK ) {
        strcpy((char*)buf, "Error Rx\r\n");
      } else {
   //Combine the bytes
      val = ((int16_t)buf[1] << 8) | (buf[0] );  
      sprintf((char*)buf,
              "%u UVB et ",
              ((unsigned int)val));     
      }  
   }      
   HAL_UART_Transmit(&huart2, buf, strlen((char*)buf), HAL_MAX_DELAY);  

   HAL_Delay(2000) ;
}