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Visitor II
November 14, 2024
Question

inconsistent Calibrations values.

  • November 14, 2024
  • 3 replies
  • 1028 views

Hi.. Can anyone tell me why the ADC Calibration value is not the same before and after I initialize the DAC
It seems that the value maxes out if I calibrate after I have initialized the DAC.

DAC_ADC.jpg

The calibration register is 7 bits.

The ADC also measures incorrectly if I calibrate the ADC after I have initialized the DAC.

Anyone have a good explanation?
thanks in advance.

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    3 replies

    spa23Author
    Visitor II
    November 14, 2024

    The problem is that MX_DAC1_Init() sets up the Clock again even though PeriphCommonClock_Config() has set it up correctly.

    When MX_DAC1_Init() it sets it up to use RCC_ADCDACCLKSOURCE_HCLK and that's wrong!!!!

    so it seems as if there is an error in cubeMX when using both ADC and DAC at the same time.

     

    Can be solved by removing : HAL_RCCEx_PeriphCLKConfig() in HAL_DAC_MspInit(); 

    Technical Moderator
    November 14, 2024

    Hi @spa23 ,

    Interesting case to check on our side.

    Could you please precise the used part number?

    -Amel

    spa23Author
    Visitor II
    November 19, 2024

    Part number : STM32H573IIKXQ

    Technical Moderator
    November 21, 2024

    Hi @spa23 ,

    Back again to this topic.

    I made some tests using STM32H563 and I'm getting the same calibration value before initializing DAC and after it.

    I changed clock configurations without any impact.

    I don't see clock set with RCC_ADCDACCLKSOURCE_HCLK  on DAC initialization.

    At this level, may you:

    • make same check using another device?
    • share your IOC file to compare the configuration I used with yours?

    - Amel