stm32f407 adc1 过采样
时间: 2023-06-21 11:13:13 浏览: 386
STM32F407的ADC可以使用过采样来提高采样精度。过采样是指在同样的采样时间内对同一信号进行多次采样,然后对多次采样结果进行平均,以提高采样精度。
过采样的实现步骤如下:
1. 设置ADC的通道、采样时间、采样周期等参数。
2. 启用ADC的DMA模式,将采样结果自动存储到内存中。
3. 设置过采样值和采样周期。过采样值决定了采样次数,采样周期决定了采样间隔时间。
4. 启用过采样功能,并设置为平均模式。
5. 启动ADC转换。
6. 等待DMA传输完成,然后计算平均值。
以下是一个简单的代码示例:
```
ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_InitTypeDef ADC_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
// 初始化DMA
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&adc_value;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 16;
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_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
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);
// 初始化ADC
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
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 = 1;
ADC_Init(ADC1, &ADC_InitStructure);
// 配置ADC1的通道
ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_28Cycles);
// 启用过采样功能
ADC1->CR2 |= ADC_CR2_OVER10;
ADC1->SMPR1 |= (7 << 3);
// 启用DMA模式
ADC_DMACmd(ADC1, ENABLE);
// 启动ADC转换
ADC_Cmd(ADC1, ENABLE);
ADC_SoftwareStartConv(ADC1);
// 等待DMA传输完成
while (DMA_GetFlagStatus(DMA2_Stream0, DMA_FLAG_TCIF0) == RESET);
// 计算平均值
uint32_t sum = 0;
for (int i = 0; i < 16; i++) {
sum += adc_value[i];
}
uint16_t average = sum / 16;
```
在上述代码中,我们使用了DMA模式将采样结果自动存储到内存中,并启用了过采样功能。最后计算平均值以得到更高的采样精度。