ADC采样速率太快，会偶尔有跳点

xm870408 · 发表于 2020-6-10 09:36:23

用的F405，一个周波采样256个数据的时候，会隔几秒钟出现一个大跳点，改成一个周波采样64个点的时候，就不会出现，是什么原因呢？难道速度太快，ADC采样就会跳吗？
//ADC1+DMA2初始化
void ADC1DMA_Init(void)
{
GPIO_InitTypeDef  GPIO_InitStructure ; //GPIO句柄
ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_InitTypeDef  ADC_InitStructure;
DMA_InitTypeDef  DMA_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

TIM2_Config(SAMPNT);

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);  //打开DMA2的时钟
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);//使能GPIOA时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE); //使能ADC1时钟

DMA_DeInit(DMA2_Stream0);//复位DMA2的数据流0，对应ADC1

while (DMA_GetCmdStatus(DMA2_Stream0) != DISABLE) {} //等待DMA可配置

DMA_InitStructure.DMA_Channel = DMA_Channel_0; //DMA2_Stream0，DMA_Channel_0对应ADC1
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)(&(ADC1->DR));//外设ADC地址
DMA_InitStructure.DMA_Memory0BaseAddr = (u32)ADC_PrimData; //内存地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory; //数据传输方向(从外设到内存)
DMA_InitStructure.DMA_BufferSize = DMALEN; //传输缓冲内容的大小
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //外设地址固定
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //内存地址增一
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord ; //外设数据宽度16位
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord ; //内存数据单位宽度16位
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; //DMA模式：循环传输
DMA_InitStructure.DMA_Priority = DMA_Priority_High ; //优先级：高
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; //直接模式，外设一产生数据立刻传输到存储器
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;//存储器突发单次传输
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;//外设突发单次传输
DMA_Init(DMA2_Stream0, &DMA_InitStructure);  //配置DMA1的1通道

NVIC_InitStructure.NVIC_IRQChannel = DMA2_Stream0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //抢占优先级0
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;          //子优先级1
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure); //初始化DMA中断

DMA_ClearITPendingBit(DMA2_Stream0, DMA_IT_TC); //清除中断标志
DMA_ITConfig(DMA2_Stream0, DMA_IT_TC, ENABLE); //打开DMA传输完成中断

DMA_Cmd(DMA2_Stream0, ENABLE);

//ADC引脚配置
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 ;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;//不带上下拉
GPIO_Init(GPIOA, &GPIO_InitStructure); //初始化

RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC1, ENABLE);    //ADC1复位
RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC1, DISABLE); //复位结束

ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent ; //独立模式，即ADC1和ADC2分开
ADC_CommonInitStructure.ADC_TwoSamplingDelay  = ADC_TwoSamplingDelay_20Cycles;//两个采样阶段之间的延迟5个时钟
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled; //DMA失能
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div8;//预分频4分频。ADCCLK=PCLK2/4=84/4=21Mhz,ADC时钟最好不要超过36Mhz
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1;
ADC_CommonInit(&ADC_CommonInitStructure);//初始化

ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;//12位模式
ADC_InitStructure.ADC_ScanConvMode = ENABLE;//扫描模式
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE ;  //单次转换，即转换一次需要软件触发一次

//ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
//ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConvEdge_None;//软件启动
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_Rising; //上升沿触发
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T2_CC2;  //定时器事件2触发ADC
ADC_InitStructure.ADC_DataAlign       = ADC_DataAlign_Right  ;  //数据存储器右对齐，因其为12位ADC，故剩下四位数据存储器为空
ADC_InitStructure.ADC_NbrOfConversion = SAMCHN;  //顺序进行规则转换的ADC通道数量为4
ADC_Init(ADC1, &ADC_InitStructure); //初始化指定ADC

ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_480Cycles); //IA的采样通道
ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_480Cycles); //IB的采样通道
ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_480Cycles); //IC的采样通道
ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_144Cycles); //U0的采样通道

ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE); //ADC1不断请求DMA2传输,（否则只会进入一次中断）
      ADC_MultiModeDMARequestAfterLastTransferCmd(ENABLE);

ADC_Cmd(ADC1, ENABLE);             //使能指定ADC
ADC_DMACmd(ADC1, ENABLE);          //使能指定的ADC-DMA传输
}