/*    DAC.h    用于定义和扩展DAC.c中的函数*/#ifndef __DAC_H__#define __DAC_H__    void DAC_Config(void); void DAC_Task(void* prg); void DAC_DMA_Config(void);#endif

/*    DAC.c    用于DAC的初始化和配置*/#include "includes.h"//定义DAC_DHR12R1 寄存器映像的实际物理地址，DAC数据格式为12位右对齐#define DAC_DHR12R1_Address 0x40007408//DAC_DHR12R1寄存器实际物理地址const u16 Escalator16bit[5] = {0,511,1023,2047,4095};    //定义阶梯波形的具体数值                        void DAC_Config(void); void DAC_Task(void* prg); void DAC_DMA_Config(void);void DAC_Task(void* prg){//    DAC_SetChannel1Data(DAC_Align_12b_R,1028);    //设置数据右对齐，转换值设置为1028//    DAC_SoftwareTriggerCmd(DAC_Channel_1,ENABLE);    //软件触发通道1 开始转换//    DAC_SetChannel2Data(DAC_Align_12b_R,2047);    //设置数据右对齐，转换值设置为2047//    DAC_SoftwareTriggerCmd(DAC_Channel_2,ENABLE);    //软件触发通道2 开始转换    DAC_DMA_Config();    //DAC的DMA配置    DAC_Config();    //DAC定时器2触发初始化配置//    while(1)//    {        OSTimeDlyHMSM(0,0,1,0);//    }}//配置DAC使用定时器触发void DAC_Config(void){    DAC_InitTypeDef DAC_InitStructure;                  //DAC库函数结构体    GPIO_InitTypeDef GPIO_InitStructure;            //GPIO结构体    RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC , ENABLE);   //DAC 时钟使能    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);   //GPIO 时钟使能    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 , ENABLE);   //TIM2定时器 时钟使能    //将GPIO配置为DAC的模拟复用功能    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4|GPIO_Pin_5;    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;         //使用手册规定该引脚需模拟输入 防止干扰    GPIO_Init(GPIOA,&GPIO_InitStructure);  //A4为通道1 A5为通道2    //TIM2配置    TIM_PrescalerConfig(TIM2,36-1,TIM_PSCReloadMode_Update); //设置预分频36    1MHz计数周期    TIM_SetAutoreload(TIM2,20-1);    //设置定时器计数器数值    //TIM2触发模式选择，此处定义为定时器2溢出更新触发    TIM_SelectOutputTrigger(TIM2,TIM_TRGOSource_Update);                                                                //DAC通道1、通道2配置    DAC_InitStructure.DAC_Trigger = DAC_Trigger_T2_TRGO;       //设置触发方式为定时器2触发    DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;     //无波形产生    DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;    //DAC输出缓冲使能    DAC_Init(DAC_Channel_1 ,&DAC_InitStructure); //使能以上设置到DAC1    DAC_Cmd(DAC_Channel_1 ,ENABLE);      //最后的开关     //PA4输出    //使能DAC通道1的DMA    DAC_DMACmd(DAC_Channel_1, ENABLE);    //使能定时器2    TIM_Cmd(TIM2, ENABLE);//    DAC_Task(0);                     }void DAC_DMA_Config(void){    DMA_InitTypeDef DMA_InitStructure;    //定义DMA初始化结构体    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2,ENABLE);//使能DMA时钟    DMA_DeInit(DMA2_Channel3); //根据默认设置初始化DMA2    DMA_InitStructure.DMA_PeripheralBaseAddr =     DAC_DHR12R1_Address;    //外设地址    DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&Escalator16bit;    //内存地址    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;    //外设作为目的地    DMA_InitStructure.DMA_BufferSize = 5;    //数据长度为5    DMA_InitStructure.DMA_PeripheralInc = DMA_MemoryInc_Disable;    //外设地址不递增    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;    //内存地址递增                DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;    //外设传输以半字节为单位    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;    //内存以半字节为单位    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;    //循环模式    DMA_InitStructure.DMA_Priority = DMA_Priority_High;//4优先级之一的高    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;    //非内存到内存    DMA_Init(DMA2_Channel3, &DMA_InitStructure);    //使能以上配置    //使能DMA2的通道3    DMA_Cmd(DMA2_Channel3,ENABLE);            }