STM32f3 - Multiple ADC

Question

I have and STM32f3 Discovery Board, and I'm trying to use 4 ADC channels. This is my read function:

int ADC_read(int channel)
{
    ADC_RegularChannelConfig(ADC1, channel, 1, ADC_SampleTime_7Cycles5);
    ADC_StartConversion(ADC1);
    while (ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) != SET);
    return ADC_GetConversionValue(ADC1);    
}

everything goes perfectly well, until suddenly program stucks in the while loop. is there a way to avoid putting a ADC_FLAG_EOC in a loop? or just some other way to make my program work?

marian0 marian0 · Accepted Answer · 2016-01-16T14:14:24

Is far as I understand depending on which version of the board you are using you must use ADC_SoftwareStartConvCmd or ADC_StartConversion.

So maybe you are not starting ADC conversion properly, please try with this:

ADC_RegularChannelConfig(ADC1, channel, 1, ADC_SampleTime_7Cycles5);

#if defined(SERIES_STM32F10x)
  ADC_SoftwareStartConvCmd(ADC1, ENABLE);
#elif defined(SERIES_STM32F30x)
  ADC_StartConversion(ADC1);
#else
  ADC_SoftwareStartConv(ADC1);
#endif

while(ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET);
return ADC_GetConversionValue(ADC1);

Also, Don't forget to you set your pins mode to input with: pinMode(pin, INPUT_ANALOG);

Finally, take a look at this post where the user had a similar problem to yours and solved it by re-enabling external trigger with:

ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;

STM32f3 - Multiple ADC

2 Answers