STM32——DAC生成正弦波

#include <stdio.h>
#include "math.h"

/*
int main()//别人的 参考下
{
    int index=256;
    double out=0;
    double pi=3.1415;
    for (int i = 0; i < index; i++)
    {
        out = ((sin((2*i*pi)/index)+1)*2047);
        printf("the buffer is:%lf",out);
    }
    return 0;
}
*/


/*
int main(int argc, char const *argv[])//一个完整的周期
{
    int index=255;
    float pi = 3.1415;
    int Fori=0;
    float outV;
    for (int Fori = 0; Fori <= index; Fori++)
    {
       outV = sin(2*pi/index*Fori)*3300;
       printf("%lf	",outV);
       if(!((Fori+1)%8))
       printf("
");
    }
    return 0;
}*/


int main(int argc, char const *argv[])//半个周期
{
    int index=255;
    float pi = 3.1415;
    int Fori=0;
    float outV;
    for (int Fori = 0; Fori <= index; Fori++)
    {
       outV = sin(pi/index*Fori)*3300;
       printf("%lf	",outV);
       if(!((Fori+1)%8))
       printf("
");
    }
    return 0;
}

运行结果——数据：
半个周期：

一个周期：

程序：就是通过DAC把这些点发出去
图片上的（sin((2*PI)/256))*X应该是（sin(X2*PI/256)）,半个周期同理**

/*补上代码*/

void Dac1_Init(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	DAC_InitTypeDef DAC_InitType;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE );	  //使能PORTA通道时钟
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE );	  //使能DAC通道时钟 

	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;				 // 端口配置
 	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN; 		 //模拟输入
 	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 	GPIO_Init(GPIOA, &GPIO_InitStructure);
	GPIO_SetBits(GPIOA,GPIO_Pin_4)	;//PA.4 输出高
					
	DAC_InitType.DAC_Trigger=DAC_Trigger_None;	//不使用触发功能 TEN1=0
	DAC_InitType.DAC_WaveGeneration=DAC_WaveGeneration_None;//不使用波形发生
	DAC_InitType.DAC_LFSRUnmask_TriangleAmplitude=DAC_LFSRUnmask_Bit0;//屏蔽、幅值设置
	DAC_InitType.DAC_OutputBuffer=DAC_OutputBuffer_Disable ;	//DAC1输出缓存关闭 BOFF1=1
  DAC_Init(DAC_Channel_1,&DAC_InitType);	 //初始化DAC通道1

	DAC_Cmd(DAC_Channel_1, ENABLE);  //使能DAC1
  
  DAC_SetChannel1Data(DAC_Align_12b_R, 0);  //12位右对齐数据格式设置DAC值
}

void TIM4_Config(void)
{
	TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	NVIC_InitTypeDef				 NVIC_InitTypeStructure;
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);	//使能定时器4时钟
	
	TIM_TimeBaseStructure.TIM_Period = 1000-1; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
	TIM_TimeBaseStructure.TIM_Prescaler =72-1; //设置用来作为TIMx时钟频率除数的预分频值 
	TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式
	TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
	
	NVIC_InitTypeStructure.NVIC_IRQChannel=TIM4_IRQn;
	NVIC_InitTypeStructure.NVIC_IRQChannelPreemptionPriority=3;
	NVIC_InitTypeStructure.NVIC_IRQChannelSubPriority=3;
	NVIC_InitTypeStructure.NVIC_IRQChannelCmd=ENABLE;
	NVIC_Init(&NVIC_InitTypeStructure);
	
	TIM_ITConfig(TIM4, TIM_IT_Update, ENABLE);
	TIM_Cmd(TIM4, ENABLE);  //使能TIM3
}

void TIM4_IRQHandler(void)
{
	if(TIM_GetFlagStatus(TIM4, TIM_FLAG_Update)==SET)
	{
		
		Vout=sin(PI/255*i)*4095;
		Vdac=Vout;
		printf("Vdac = %d, Vout = %lf 
",Vdac,Vout);
		i++;
		if(i==255)
			i=0;
		TIM_ClearFlag(TIM4, TIM_FLAG_Update);
	}
}

将

printf("Vdac = %d, Vout = %lf 
",Vdac,Vout);

用

DAC_SetChannel1Data(DAC_Align_12b_R, Vdac);  //12位右对齐数据格式设置DAC值

替换即可