ADC reset calibration fails. Ideas why?

Posted on May 17, 2011 at 14:15

ST advise, ''Before starting a calibration the ADC must have been in power-off state (ADON bit = ‘0’) for at least two ADC clock cycles.''

But ... your code looks very like mine (which works).

void ADC_Configuration(void)

{

  ADC_InitTypeDef  ADC_InitStructure;

  //ADC_ContinuousConvMode  conversion in Continuous or Single mode

  //ADC_DataAlign           ADC data alignment is left or right.

  //ADC_ExternalTrigConv    external trigger for conversion of regular channels

  //ADC_Mode                ADC to operate in independent or dual mode

  //ADC_NbrOfChannel        channels converted using sequencer for regular channel group. range 1..16

  //ADC_ScanConvMode        scan (multichannels) or single (one channel) mode

  //Deinitialize the ADCx peripheral registers to their default reset values.

  ADC_DeInit(ADC1);

  //ADC1 Configuration

  ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;

  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;

  ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;

  ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;

  ADC_InitStructure.ADC_NbrOfChannel = 1;

  ADC_InitStructure.ADC_ScanConvMode = DISABLE;

  ADC_Init(ADC1, &ADC_InitStructure);

  //Enable ADC1 powers ADC for first time (CR2_ADON was 0)

  ADC_Cmd(ADC1, ENABLE);

  ADC_ResetCalibration(ADC1);

  while(ADC_GetResetCalibrationStatus(ADC1));

  ADC_StartCalibration(ADC1);

  while(ADC_GetCalibrationStatus(ADC1));

}

I wonder if you have a high level of optimisation which is messing up the status check.

Do you have a valid VRef? I don't know if this is required.