用STM32F4库函数写ADC DMA乒乓buffer

以下是使用STM32F4库函数编写ADC DMA乒乓buffer的示例代码：

#include "stm32f4xx.h"

#define BUFFER_SIZE 256

volatile uint16_t buffer1[BUFFER_SIZE];
volatile uint16_t buffer2[BUFFER_SIZE];
volatile uint16_t *current_buffer = buffer1;

void init_adc(void);
void init_dma(void);

int main(void)
{
    init_adc();
    init_dma();

    while(1)
    {
        // do something with the data in current_buffer
        // ...

        // switch to the other buffer
        if(current_buffer == buffer1)
        {
            current_buffer = buffer2;
        }
        else
        {
            current_buffer = buffer1;
        }
    }
}

void init_adc(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;
    ADC_InitTypeDef ADC_InitStruct;

    // enable GPIOA clock
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

    // configure PA0 for analog input
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AN;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    // enable ADC1 clock
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

    // configure ADC1
    ADC_InitStruct.ADC_Resolution = ADC_Resolution_12b;
    ADC_InitStruct.ADC_ScanConvMode = DISABLE;
    ADC_InitStruct.ADC_ContinuousConvMode = ENABLE;
    ADC_InitStruct.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
    ADC_InitStruct.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStruct.ADC_NbrOfConversion = 1;
    ADC_Init(ADC1, &ADC_InitStruct);

    // configure ADC1 regular channel
    ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_15Cycles);

    // enable ADC1 DMA
    ADC_DMACmd(ADC1, ENABLE);

    // enable ADC1
    ADC_Cmd(ADC1, ENABLE);

    // wait for ADC1 to be ready
    while(!ADC_GetFlagStatus(ADC1, ADC_FLAG_RDY));
}

void init_dma(void)
{
    DMA_InitTypeDef DMA_InitStruct;

    // enable DMA2 clock
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);

    // configure DMA2 stream 0
    DMA_InitStruct.DMA_Channel = DMA_Channel_0;
    DMA_InitStruct.DMA_PeripheralBaseAddr = (uint32_t) &ADC1->DR;
    DMA_InitStruct.DMA_Memory0BaseAddr = (uint32_t) current_buffer;
    DMA_InitStruct.DMA_DIR = DMA_DIR_PeripheralToMemory;
    DMA_InitStruct.DMA_BufferSize = BUFFER_SIZE;
    DMA_InitStruct.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStruct.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStruct.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    DMA_InitStruct.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
    DMA_InitStruct.DMA_Mode = DMA_Mode_Circular;
    DMA_InitStruct.DMA_Priority = DMA_Priority_High;
    DMA_InitStruct.DMA_FIFOMode = DMA_FIFOMode_Disable;
    DMA_InitStruct.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
    DMA_InitStruct.DMA_MemoryBurst = DMA_MemoryBurst_Single;
    DMA_InitStruct.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
    DMA_Init(DMA2_Stream0, &DMA_InitStruct);

    // enable DMA2 stream 0
    DMA_Cmd(DMA2_Stream0, ENABLE);
}

此示例代码将ADC1配置为连续模式，每次转换一个模拟输入通道（PA0），并使用DMA将转换结果存储在乒乓缓冲区（buffer1和buffer2）中。在主循环中，程序将从当前缓冲区中读取数据进行处理，并在处理完数据后切换到另一个缓冲区以继续接收ADC数据。请注意，DMA配置为循环模式，因此它将在填满一个缓冲区后自动切换到另一个缓冲区。