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急!ADCProcessorTrigger不起作用 TM4C123GH6PM

Tianli Zhang
Prodigy 60 points


配置好ADC后调用ADCProcessorTrigger,然后观察ADC_PSSI的值,发现ADC_PSSI始终为零,

直接用HWREG(ADC0_BASE+ADC_0_PSSI)  来写寄存器ADC_PSSI的值依然为零,

配置ADC的函数为:

void InitADC()
{
    SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    GPIOPinTypeADC(GPIO_PORTD_BASE,GPIO_PIN_2);


    ADCSequenceConfigure(ADC0_BASE, 3, ADC_TRIGGER_PROCESSOR, 0);
    ADCSequenceStepConfigure(ADC0_BASE, 3, 0, ADC_CTL_CH0 | ADC_CTL_IE | ADC_CTL_END);


    ADCReferenceSet(ADC0_BASE, ADC_REF_INT);
    ADCClockConfigSet(ADC0_BASE, ADC_CLOCK_SRC_PLL | ADC_CLOCK_RATE_FULL, 24);


    ADCIntEnable(ADC0_BASE,3);
    IntEnable(INT_ADC0SS3_TM4C123);
    IntMasterEnable();

    ADCIntClear(ADC0_BASE,3);
    ADCSequenceEnable(ADC0_BASE,3);
}

然后在main里的:

while(1)

{

    //        ADCProcessorTrigger(ADC0_BASE, 3);

   HWREG(ADC0_BASE + ADC_0_PSSI) |= ((3 & 0xffff0000) | (1 << (3 & 0xf)));

   while(!ADCIntStatus(ADC0_BASE, 3, false))
        {
        }
    ADCIntClear(ADC0_BASE, 3);
    ADCSequenceDataGet(ADC0_BASE, 3, Buffer);
    SysCtlDelay(SysCtlClockGet() / 12);

}

启动采样

但是无论是运行ADCProcessorTrigger还是运行HWREG,ADC_PSSI的值都不会变化,再往后执行,则在

   while(!ADCIntStatus(ADC0_BASE, 3, false))这一句跑飞

我认为问题应该出在ADCProcessorTrigger这一步上,

急求解答!

谢谢!

  • 0
    TI__Expert 3830 points

    楼主，

      建议参考TIvaware下的...\examples\peripherals\adc下的范例代码；

  • 0 回复 step by step
    Prodigy 60 points

    完全按照例程写的,可是不行,没法用ADCProcessorTrigger触发采样,

    我刚刚又发现,如果先写ADC_PSSI_SYNCWAIT,再写ADC_PSSI_SYNCWAIT,那么ADC_PSSI_SSn是可以写进1的,但是直接写ADC_PSSI_SSn就不行,

    于是我就想先写ADC_PSSI_SYNCWAIT再写ADC_PSSI_SSn然后再把ADC_PSSI_SYNCWAIT clear掉来启动采样,但是,

    把ADC_PSSI_SYNCWAIT clear掉的同时ADC_PSSI_SSn也被 clear了...

    结果还是无法采样

    急用,真心求解答,谢谢!

  • 0 回复 Tianli Zhang
    TI__Genius 13962 points

    例程的代码没有问题的。

    再分享一个给你，用ADC采集内部温度传感器的：

    #include <stdint.h>
    #include <stdbool.h>
    #include "inc/hw_memmap.h"
    #include "inc/hw_types.h"
    #include "driverlib/debug.h"
    #include "driverlib/sysctl.h"
    #include "driverlib/adc.h"

    #ifdef DEBUG
    void__error__(char *pcFilename, uint32_t ui32Line)
    {
    }
    #endif

    int main(void)
    {
    uint32_t ui32ADC0Value[4];
    volatile uint32_t ui32TempAvg;
    volatile uint32_t ui32TempValueC;
    volatile uint32_t ui32TempValueF;

    SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_XTAL_16MHZ);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);

    ADCSequenceConfigure(ADC0_BASE, 1, ADC_TRIGGER_PROCESSOR, 0);
    ADCSequenceStepConfigure(ADC0_BASE, 1, 0, ADC_CTL_TS);
    ADCSequenceStepConfigure(ADC0_BASE, 1, 1, ADC_CTL_TS);
    ADCSequenceStepConfigure(ADC0_BASE, 1, 2, ADC_CTL_TS);
    ADCSequenceStepConfigure(ADC0_BASE,1,3,ADC_CTL_TS|ADC_CTL_IE|ADC_CTL_END);
    ADCSequenceEnable(ADC0_BASE, 1);

    while(1)
    {
    ADCIntClear(ADC0_BASE, 1);
    ADCProcessorTrigger(ADC0_BASE, 1);

    while(!ADCIntStatus(ADC0_BASE, 1, false))
    {
    }

    ADCSequenceDataGet(ADC0_BASE, 1, ui32ADC0Value);
    ui32TempAvg = (ui32ADC0Value[0] + ui32ADC0Value[1] + ui32ADC0Value[2] + ui32ADC0Value[3] + 2)/4;
    ui32TempValueC = (1475 - ((2475 * ui32TempAvg)) / 4096)/10;
    ui32TempValueF = ((ui32TempValueC * 9) + 160) / 5;
    }
    }

    采集的输入不一样，但是原理流程都是一样的，仔细对照修改吧。