Forum: µC & Digital Electronics reading 24bit with I2S on nucleo stm32f411re

Author: Mike (Guest)
Posted on:

Rate this post
0 useful
not useful

I am new to microcontroller programming. I am trying to read a digital 
microphone with a 24bit i2s interface. My problem is that the results I 
get are just uint16_t thus I loose some bits.
I'm using st cube and HAL. The api documentation is:
  * @brief Receive an amount of data in blocking mode 
  * @param  hi2s: pointer to a I2S_HandleTypeDef structure that contains
  *         the configuration information for I2S module
  * @param pData: a 16-bit pointer to data buffer.
  * @param Size: number of data sample to be sent:
  * @note When a 16-bit data frame or a 16-bit data frame extended is selected during the I2S
  *       configuration phase, the Size parameter means the number of 16-bit data length 
  *       in the transaction and when a 24-bit data frame or a 32-bit data frame is selected 
  *       the Size parameter means the number of 16-bit data length. 
  * @param Timeout: Timeout duration
  * @note The I2S is kept enabled at the end of transaction to avoid the clock de-synchronization 
  *       between Master and Slave(example: audio streaming).
  * @note In I2S Master Receiver mode, just after enabling the peripheral the clock will be generate
  *       in continuous way and as the I2S is not disabled at the end of the I2S transaction.
  * @retval HAL status
HAL_StatusTypeDef HAL_I2S_Receive(I2S_HandleTypeDef *hi2s, uint16_t *pData, uint16_t Size, uint32_t Timeout)
I tried
uint16_t I2S_RX_BUFFER2[24];
 HAL_I2S_Receive(&hi2s1, (uint16_t*)I2S_RX_BUFFER2, 24, 0x1000);
My i2s is initialized for 24bit MSB first. How can I get 24bit results?


Entering an e-mail address is optional. If you want to receive reply notifications by e-mail, please log in.

Rules — please read before posting

  • Post long source code as attachment, not in the text
  • Posting advertisements is forbidden.

Formatting options

  • [c]C code[/c]
  • [avrasm]AVR assembler code[/avrasm]
  • [code]code in other languages, ASCII drawings[/code]
  • [math]formula (LaTeX syntax)[/math]

Bild automatisch verkleinern, falls nötig
Note: the original post is older than 6 months. Please don't ask any new questions in this thread, but start a new one.