[参考译文] TM4C129ENCPDT：ADC 读数不正确

https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1333341/tm4c129encpdt-adc-reading-not-correct

您好！

我已经配置了微控制器的内部 ADC。 我会收到正确的 AIN0、 AIN1、AIN2 、AIN3值 、但对于 AIN8和 AIN9、会输出错误的值。 我想它是否与通道顺序有关、因为 AIN3和 AIN8之间缺少 ADC 通道。

我已经为上述信号配置了控制器的端口 E。

以下是我的代码；

端口引脚定义 如下所示；

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

ADC INIT 函数就在这里；

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);
}

初始化后、我会调用以下函数来收集数据并保存到不同的变量中。

//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

}

如前所述、我们可以正确读取  AIN0、 AIN1、 AIN2、AIN3 的所有值、但 AIN8和 AIN9的所有值不报告正确的值。

有任何想法/提示吗？

谢谢