stm32f103r6 ADC参考电源为5V，利用ADC对3个通道PA1、PA2和PA3进行连续扫描采样，并通过串口打印三个通道上的模拟电压值。提交keil主函数 ，ADC.c和DMA.c

以下是对应的代码：

主函数 main.c：

#include "stm32f10x.h"
#include "usart.h"
#include "adc.h"
#include "dma.h"

uint16_t ADC_Value[3];

int main(void)
{
    USART_Config();
    ADC_Config();
    DMA_Config();

    while (1)
    {
        printf("PA1: %d mV, PA2: %d mV, PA3: %d mV\n",
            ADC_Value[0] * 5000 / 4096,
            ADC_Value[1] * 5000 / 4096,
            ADC_Value[2] * 5000 / 4096);
        delay_ms(1000);
    }
}

ADC.c：

#include "adc.h"

void ADC_Config(void)
{
    ADC_InitTypeDef ADC_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_ADC1, ENABLE);

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    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 = 3;
    ADC_Init(ADC1, &ADC_InitStructure);

    ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_239Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 2, ADC_SampleTime_239Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 3, ADC_SampleTime_239Cycles5);

    ADC_DMACmd(ADC1, ENABLE);

    ADC_Cmd(ADC1, ENABLE);

    ADC_ResetCalibration(ADC1);
    while (ADC_GetResetCalibrationStatus(ADC1))
        ;

    ADC_StartCalibration(ADC1);
    while (ADC_GetCalibrationStatus(ADC1))
        ;

    ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}

DMA.c：

#include "dma.h"

void DMA_Config(void)
{
    DMA_InitTypeDef DMA_InitStructure;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

    DMA_DeInit(DMA1_Channel1);

    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) & (ADC1->DR);
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t) ADC_Value;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
    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_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel1, &DMA_InitStructure);

    DMA_Cmd(DMA1_Channel1, ENABLE);
}