定时器 DMA_ADC规则通道的交流电压采样转换代码

以下是基于STM32的定时器、DMA和ADC模块的交流电压采样转换代码：

#include "stm32f10x.h"

#define ADC1_DR_Address ((uint32_t)0x4001244C)

uint16_t ADC_ConvertedValue[2];

void ADC_DMA_Config(void)
{
  DMA_InitTypeDef DMA_InitStructure;
  ADC_InitTypeDef ADC_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;
  TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_TIM1 | RCC_APB2Periph_AFIO, ENABLE);
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

  DMA_DeInit(DMA1_Channel1);

  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_Address;
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)ADC_ConvertedValue;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
  DMA_InitStructure.DMA_BufferSize = 2;
  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);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  ADC_DeInit(ADC1);

  ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
  ADC_InitStructure.ADC_ScanConvMode = ENABLE;
  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
  ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
  ADC_InitStructure.ADC_NbrOfChannel = 1;
  ADC_Init(ADC1, &ADC_InitStructure);

  ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 1, 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));

  TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseInitStructure.TIM_Period = 42000;
  TIM_TimeBaseInitStructure.TIM_Prescaler = 1;
  TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStructure);

  TIM_OCInitTypeDef TIM_OCInitStructure;
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 21000;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OC1Init(TIM1, &TIM_OCInitStructure);

  TIM_Cmd(TIM1, ENABLE);
}

int main(void)
{
  ADC_DMA_Config();

  while(1);
}

上述代码中使用了定时器1作为ADC采样的外部触发源，并且使用DMA1通道1实现了ADC数据的传输。在主函数中调用了ADC_DMA_Config()函数进行配置，其中ADC_ConvertedValue数组用于存储ADC采样结果，GPIOA的第5个引脚用于连接交流电源。

此外，在TIM1中使用了PWM输出模式，并且设置了占空比为50%的PWM信号，用于作为交流电源的输入。可以根据需要调整TIM1的频率和占空比，以适应不同的交流电源。