STM32F407 多通道ADC+DMA出来的数据不对

1楼-- · 2019-07-21 00:00

本帖最后由 nxcosa 于 2016-9-4 01:09 编辑

正点原子发表于 2016-9-3 20:03
计算有问题啊。。。

原子哥，问题找到了，有三个问题。
1.应该使用void  Adc_Init()初始化，不能使用void  Adc_Init(u32 mar)。  这是为什么？
2.ADC_SoftwareStartConv(ADC1);应该放在ADC_Cmd(ADC1, ENABLE);的后面，放在前面就会出现问题。
3.接受数组的定义u32 mar[6]；应该放在main函数的外面，并且在adc.c中要加外部变量什么extern u32 mar[6];
[mw_shl_code=c,true]extern u32 mar[6];

void  Adc_Init()
{
      GPIO_InitTypeDef  GPIO_InitStructure;
      ADC_CommonInitTypeDef ADC_CommonInitStructure;
      ADC_InitTypeDef    ADC_InitStructure;
      DMA_InitTypeDef  DMA_InitStructure;

      RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
      RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2,ENABLE);

      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5|GPIO_Pin_4|GPIO_Pin_3|GPIO_Pin_2|GPIO_Pin_1|GPIO_Pin_0;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
      GPIO_Init(GPIOA, &GPIO_InitStructure);

      RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC1,ENABLE);
      RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC1,DISABLE);

      ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
      ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_20Cycles;
      ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
      ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div4;
      ADC_CommonInit(&ADC_CommonInitStructure);

      ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
      ADC_InitStructure.ADC_ScanConvMode = ENABLE;
      ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
      ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
      ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
      ADC_InitStructure.ADC_NbrOfConversion = 6;
      ADC_Init(ADC1, &ADC_InitStructure);

      DMA_DeInit(DMA2_Stream0);
      while (DMA_GetCmdStatus(DMA2_Stream0) != DISABLE) {}


      DMA_InitStructure.DMA_Channel = DMA_Channel_0;
      DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&ADC1->DR;
      DMA_InitStructure.DMA_Memory0BaseAddr = (u32)mar;
      DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
      DMA_InitStructure.DMA_BufferSize = 6;
      DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
      DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
      DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
      DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
      DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
      DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
      DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
      DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
      DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
      DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
      DMA_Init(DMA2_Stream0, &DMA_InitStructure);
      DMA_Cmd(DMA2_Stream0,ENABLE);

      ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_144Cycles );
      ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_144Cycles );
      ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_144Cycles );
      ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_144Cycles );
      ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 5, ADC_SampleTime_144Cycles );
      ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 6, ADC_SampleTime_144Cycles );


      ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
      ADC_DMACmd(ADC1,ENABLE);
      ADC_Cmd(ADC1, ENABLE);
  ADC_SoftwareStartConv(ADC1);
}

u32 mar[6];

int main(void)
{

      u8 i;
      NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//éèÖÃÏμí3ÖD¶ÏóÅÏè¼¶·Ö×é2
      delay_init(168); //3õê¼»ˉÑóê±oˉêy
      uart_init(115200);       //3õê¼»ˉ′®¿ú2¨ìØÂêÎa115200
      LED_Init();
      Adc_Init();       //3õê¼»ˉADC

      while(1)
      {

            if(DMA_GetFlagStatus(DMA2_Stream0,DMA_FLAG_TCIF0)!=RESET)
            {
                     for(i = 0; i < 6; i++)
                     {
                              printf("adc%d  =%4.2f  ",i,mar*3.3/4096);
                     }

                     printf(" ");

                     DMA_ClearFlag(DMA2_Stream0,DMA_FLAG_TCIF0);
            }

            LED0=!LED0;
            delay_ms(250);
      }
}
[/mw_shl_code]
如果我想要想串口DMA那样，可以在初始化的时候才输入数组的地址？我对输入数组地址有点疑惑，不是输入数组名就是数组的起始地址吗？那为什么我上面的那种跑不通？正确方法应该是怎么样的呢？