我的ADC配置如下:- u16 ADC_ConvertedValue[M];
- u16 ADC_ConvertedValueLocal[M];
- u16 Upa,Upb,Upc;
- void ADC1_Init(void)
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- ADC_InitTypeDef ADC_InitStructure;
- DMA_InitTypeDef DMA_InitStructure;
-
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA ,ENABLE);
- RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1,ENABLE);
- RCC_ADCCLKConfig(RCC_PCLK2_Div6);
-
- GPIO_InitStructure.GPIO_Pin=GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6;
- GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AIN;
- GPIO_Init(GPIOA, &GPIO_InitStructure);
-
- DMA_DeInit(DMA1_Channel1);
- DMA_InitStructure.DMA_PeripheralBaseAddr=(ADC1->DR);
- DMA_InitStructure.DMA_MemoryBaseAddr=(u32)&ADC_ConvertedValue;
- DMA_InitStructure.DMA_DIR=DMA_DIR_PeripheralSRC;
- DMA_InitStructure.DMA_BufferSize=M;
- DMA_InitStructure.DMA_PeripheralInc=DMA_PeripheralInc_Disable;
- DMA_InitStructure.DMA_MemoryInc=DMA_MemoryInc_Enable;
- DMA_InitStructure.DMA_PeripheralDataSize=DMA_PeripheralDataSize_HalfWord;
- DMA_InitStructure.DMA_MemoryDataSize=DMA_MemoryDataSize_HalfWord;
- DMA_InitStructure.DMA_Mode=DMA_Mode_Circular;
- DMA_InitStructure.DMA_Priority=DMA_Priority_High;
- DMA_InitStructure.DMA_M2M=DMA_M2M_Disable;
- DMA_Init(DMA1_Channel1,&DMA_InitStructure);
-
-
- ADC_DeInit(ADC1);
- ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
- ADC_InitStructure.ADC_ScanConvMode=ENABLE;
- ADC_InitStructure.ADC_ContinuousConvMode=ENABLE;
- ADC_InitStructure.ADC_ExternalTrigConv=ADC_ExternalTrigConv_None;
- ADC_InitStructure.ADC_DataAlign=ADC_DataAlign_Right;
- ADC_InitStructure.ADC_NbrOfChannel=M;
- ADC_Init(ADC1, &ADC_InitStructure);
- ADC_RegularChannelConfig(ADC1, ADC_Channel_4,1,ADC_SampleTime_239Cycles5);
- ADC_RegularChannelConfig(ADC1, ADC_Channel_5,2,ADC_SampleTime_239Cycles5);
- ADC_RegularChannelConfig(ADC1, ADC_Channel_6,3,ADC_SampleTime_239Cycles5);
-
- ADC_Cmd(ADC1, ENABLE);
- ADC_DMACmd(ADC1, ENABLE);
-
- ADC_ResetCalibration(ADC1);
- while(ADC_GetResetCalibrationStatus(ADC1));
- ADC_StartCalibration(ADC1);
- while(ADC_GetCalibrationStatus(ADC1));
- DMA_Cmd(DMA1_Channel1,ENABLE);
- ADC_SoftwareStartConvCmd(ADC1, ENABLE);
- }
主函数如下:- u8 i;
- int main(void)
- {
- uart_init(9600);
- CHIP_PWM_Init(8999);
- ADC1_Init();
- LED_Init();
- while(1)
- {
- LED2=!LED2;
- printf("\r\n let's a test \r\n\r\n");
-
- change();
- for(i=0;i<3;i++)
- {
- ADC_ConvertedValueLocal[i]=ADC_ConvertedValue[i]*33000/4096;
- }
- printf("\r\n Upa=%d \r\n\r\n",ADC_ConvertedValueLocal[0]);
- printf("\r\n Upb=%d \r\n\r\n",ADC_ConvertedValueLocal[1]);
- printf("\r\n Upc=%d \r\n\r\n",ADC_ConvertedValueLocal[2]);
- }
- }
采样后打印出来的结果,三路数据的值都是一样的。而且用示波器测量三路数据均为PWM波,波形如下,打印结果却显示三路数据永远都是高电平。请问这是为什么呢?

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