TM4C129ENCPDT: ADC Reading not correct

Hi,

I have configured the Internal ADC of the microcontroller. I am receiving correct values for AIN0, AIN1, AIN2, AIN3, however for AIN8 and AIN9 it would be spitting wrong values. I am guessing, if it has something to do with the order of the channels since there is missing ADC channels between AIN3 and AIN8.

I have configured Port E of the controller for the above signals.

Here is my code;

The port pin definitions are below;

uint32_t IntADCRawData0[8]; //Buffer array that holds ADC samples

//On Board ADC Signals Pins map connected to microcontroller internal ADC
#define ADC_PIN_33Volt GPIO_PIN_0
#define ADC_PIN_5Volt GPIO_PIN_1
#define ADC_PIN_15NegVolt GPIO_PIN_2
#define ADC_PIN_15PosVolt GPIO_PIN_3
#define ADC_PIN_VCF GPIO_PIN_4
#define ADC_PIN_VC2 GPIO_PIN_5


#define ADC_CH_33Volt           ADC_CTL_CH3 //PE0 = AIN3
#define ADC_CH_5Volt            ADC_CTL_CH2 //PE1 = AIN2
#define ADC_CH_15NegVolt        ADC_CTL_CH1 //PE2 = AIN1
#define ADC_CH_15PosVolt        ADC_CTL_CH0 //PE3 = AIN0
#define ADC_CH_VCFVolt          ADC_CTL_CH9 //PE4 = AIN9
#define ADC_CH_VC2Volt          ADC_CTL_CH8 //PE5 = AIN8

The ADC init function is here;

void Internal_ADC0_Init(void)
{
    //First configure common ADC Ports and Pins
    // *** Peripheral Enable
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);
    ROM_SysCtlPeripheralReset(SYSCTL_PERIPH_GPIOE);
    SysCtlDelay(100);
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
    SysCtlDelay(100);

    //Configure the individual pins being used as ADC input pins
    ROM_GPIOPinTypeADC(GPIO_PORTE_BASE, ADC_PIN_VC2 | ADC_PIN_VCF | ADC_PIN_15PosVolt | ADC_PIN_15NegVolt | ADC_PIN_5Volt | ADC_PIN_33Volt);

    ROM_ADCReferenceSet(ADC0_BASE,ADC_REF_INT);

    ROM_ADCSequenceDisable(ADC0_BASE, 0);  //Disable sequence before we change it

    ROM_ADCSequenceConfigure(ADC0_BASE,0,ADC_TRIGGER_PROCESSOR,0); //ADC Trigger by Processor

    ROM_ADCSequenceStepConfigure(ADC0_BASE,0,0,ADC_CH_15PosVolt); //To sample Channel 0
    ROM_ADCSequenceStepConfigure(ADC0_BASE,0,1,ADC_CH_15NegVolt); //To sample Channel 1
    ROM_ADCSequenceStepConfigure(ADC0_BASE,0,2,ADC_CH_5Volt); //To sample Channel 2
    ROM_ADCSequenceStepConfigure(ADC0_BASE,0,3,ADC_CH_33Volt); //To sample Channel 3
    ROM_ADCSequenceStepConfigure(ADC0_BASE,0,4,ADC_CH_VC2Volt); //To sample Channel 8
    ROM_ADCSequenceStepConfigure(ADC0_BASE,0,5,ADC_CH_VCFVolt); //To sample Channel 9


    ROM_ADCHardwareOversampleConfigure(ADC0_BASE, 64); //Configure the hardware Averager module to average out 64 samples for each channel.

    ROM_ADCSequenceStepConfigure(ADC0_BASE,0,6,ADC_CTL_TS|ADC_CTL_IE|ADC_CTL_END);

    ROM_ADCSequenceEnable(ADC0_BASE,0);
}

After initialization, I call the following function to collect data and save in different variables.

//This function collects data from internal ADC and saves at the pointer location.
void IntADC_Collect_Data(void)
{

        // Trigger the sample sequence.
        ADCProcessorTrigger(ADC0_BASE, 0);

        //while(!ADCIntStatus(ADC0_BASE, 0, false)){} //DO NOT use this while loop as it may take forever instead use a delay
        vTaskDelay(10/portTICK_PERIOD_MS); // 10msec delay
        
        ADCSequenceDataGet(ADC0_BASE, 0, IntADCRawData0);

        volt15Pos.data.value16bits              =   0x0000FFFF & IntADCRawData0[0];
        volt15Neg.data.value16bits              =   0x0000FFFF & IntADCRawData0[1];
        volt5.data.value16bits                  =   0x0000FFFF & IntADCRawData0[2];
        volt33.data.value16bits                 =   0x0000FFFF & IntADCRawData0[3];
        VC2DAC_ReadBack.data.value16bits        =   0x0000FFFF & IntADCRawData0[4];
        VCFDAC_ReadBack.data.value16bits        =   0x0000FFFF & IntADCRawData0[5];
        ProcessorTemp.data.value16bits          =   0x0000FFFF & IntADCRawData0[6];
        Kicker_Spare_Temp.data.value16bits      =   0x0000FFFF & IntADCRawData0[7]; //This is just a place holder since in case of Septum Kicker_Spare_Temp doesnt exist

}

As I said earlier, We can read correctly all values for AIN0, AIN1, AIN2, AIN3, however for AIN8 and AIN9 are not reporting correct values.

Any idea / hint ?

Thanks