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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