adc多通道采样正弦波

以下是一段基于STM32F4的ADC多通道采样正弦波的代码，可以供参考：

#include "stm32f4xx.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_adc.h"
#include "misc.h"

#define ADC1_DR_ADDRESS    ((uint32_t)0x4001204C)

__IO uint16_t ADC1ConvertedValue[3];

void GPIO_Configuration(void);
void ADC1_Configuration(void);
void DMA_Configuration(void);

int main(void)
{
    GPIO_Configuration();
    ADC1_Configuration();
    DMA_Configuration();

    ADC_SoftwareStartConv(ADC1);
    while(1);
}

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

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

void ADC1_Configuration(void)
{
    ADC_CommonInitTypeDef ADC_CommonInitStructure;
    ADC_InitTypeDef ADC_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

    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 = 3;
    ADC_Init(ADC1, &ADC_InitStructure);

    ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_3Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_3Cycles);

    ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);

    ADC_Cmd(ADC1, ENABLE);
    while(!ADC_GetFlagStatus(ADC1, ADC_FLAG_ADEN));
}

void DMA_Configuration(void)
{
    DMA_InitTypeDef DMA_InitStructure;

    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);

    DMA_InitStructure.DMA_Channel = DMA_Channel_0;
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_ADDRESS;
    DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC1ConvertedValue;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
    DMA_InitStructure.DMA_BufferSize = 3;
    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);

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

#ifdef USE_FULL_ASSERT
void assert_failed(uint8_t* file, uint32_t line)
{
    while(1);
}
#endif

在这个例子中，我们使用了PA0、PA1和PA2三个通道来采样正弦波。首先，我们需要配置GPIO，将这三个通道设置为模拟输入。然后，我们需要配置ADC1，设置分辨率、采样时间、通道等参数。为了实现连续转换，我们需要设置扫描模式和连续转换模式。最后，我们需要启用ADC1，并等待ADC稳定后开始采样。

为了实现多通道采样，我们需要使用DMA。首先，我们需要配置DMA，设置DMA通道、传输方向、缓存地址等参数。然后，我们需要启用DMA，并将ADC的DMA请求开启。这样，在ADC每次采样后，DMA会将采样值存储到缓存中。

在这个例子中，我们使用了循环模式，即DMA会不断地将采样值存储到缓存中。我们可以在主函数中使用ADC_SoftwareStartConv函数触发ADC转换，并在while循环中等待DMA将采样值存储到缓存中。这样，我们就可以实现多通道采样正弦波了。