Kinetis MicrocontrollersのトピックRe: processor expert ADC function return previous conversion value?

processor expert ADC function return previous conversion value?

stevedecoen — Tue, 06 Dec 2016 14:31:53 GMT

Hi,

I have some ADC read function like this :

......
if(!UsbTmtUINT16(hw_uLeesAD(AD_Speaker))) return;
if(!UsbTmtUINT16(hw_uLeesAD(AD_Aux))) return;
.....

This example sends the speakers AD value and the Aux Ad value to a PC (and 22 other ADC's)

The code in hw_uLeesAD looks like this :

uint16_t hw_uLeesAD(TAdcInput AdcInput)
{
   Ttmrf ADCTimeOut;
   LDD_ADC_TSample SampleGroup[1U];
   uint16_t AdcValue;
   TAdcInputParamTab const *pAdcInputParamTab;
    pAdcInputParamTab = &AdcInputParamTab[AdcInput];
    SampleGroup[0].ChannelIdx = pAdcInputParamTab->AdInput;
    POWERAD_SEL_PutVal(pAdcInputParamTab->Multiplexer);
    ADC_CreateSampleGroup(ADC_DeviceData, (LDD_ADC_TSample *) SampleGroup,1U); //uses ChannelToPin[ adcCh_num]
   ADC_StartSingleMeasurement(ADC_DeviceData); // Start ADC
    tmrf_Start(&ADCTimeOut,0.0005);
    while (!tmrf_Ok(&ADCTimeOut))
   {
       ADC_Main(ADC_DeviceData);
       if (bADCConversionDone)
       {
           bADCConversionDone = 0;
           if (ERR_OK == ADC_GetMeasuredValues(ADC_DeviceData,(LDD_TData *) &AdcValue))
           { // Read measured values
               return AdcValue; //Capture Output
           }
       }
   }
   return 0xFFFF;
}

This code selects the correct ADC input (selected by AdcInput), and returns the ADC value from the ADC.

The problem i have is that the ADC value which is send is always the previous ADC value, so in above example i get at the PC side AD_Speaker when i expect AD_Aux. When i replace all hw_uLeesAD(AD_XXX) by constants , then it works fine.

When i run the function 2 times like this , then i receive the correct ADC value:

uint16_t adcval;
adcval = hw_uLeesAD(AD_Speaker);
if(!UsbTmtUINT16(hw_uLeesAD(AD_Speaker))) return;
adcval = hw_uLeesAD(AD_Aux);
if(!UsbTmtUINT16(hw_uLeesAD(AD_Aux))) return;

It looks like ADC_GetMeasuredValues returns a previous ADC value, but i can't find out why.

Any input is more then welcome

Thank you

Re: processor expert ADC function return previous conversion value?

Alice_Yang — Tue, 13 Dec 2016 04:07:13 GMT

Hello steve,

What about your chip part number ? And which version of IDE do you used ?

Alice

Re: processor expert ADC function return previous conversion value?

stevedecoen — Tue, 13 Dec 2016 14:58:36 GMT

MKE04Z64VLK4 , IDE code warrior 10.6.4 ,

Re: processor expert ADC function return previous conversion value?

Alice_Yang — Wed, 14 Dec 2016 04:02:00 GMT

Hello Steve,

- Sorry in fact , i don't know your code clearly , for some function is defined by you.

For example , what is "UsbTmtUINT16()" .Use the USB transfer ?

You said transfer the wrong data , i think you can check the buffer which save data to send.

- And you maybe you can use the ADC interrupt to send data , in the ADC interrupt function , save

ADC data . There are some demo about ADC :

Alice

Re: processor expert ADC function return previous conversion value?

stevedecoen — Wed, 14 Dec 2016 09:30:49 GMT

Thank you for your advice,

The transfert buffer work fine, yes these are my USB functions.

I do not want to use interrupts, i think this is a bug in processor expert .

Already replaced the ADC code with my own code which address the ADC registers directly, and now it works fine.

I was wondering if somebody got the same issues with processor expert and how they solved it

Steve

Re: processor expert ADC function return previous conversion value?

Alice_Yang — Thu, 15 Dec 2016 07:01:44 GMT

Hi Steve,

Could you please check the ADC Result register , or the in the memory view to check it,

whether the data is right.

If it really a bug, i will report it to PE team, and solve it . While just now , i don't

know you meaning where is the bug ? A function ? Or anything else ? Or the ADC result ?

Alice