#define HZ(x) (u16)(72000000/sizeof(Sine12bit)*2/x) //计算Hz
#define DAC_DHR12R1 0x40007408 //外设DAC通道1的基地址
u16 Sine12bit[256]={ //正弦波描点
2048, 2098, 2148, 2198, 2248, 2298, 2348, 2398, 2447, 2496,
2545, 2594, 2642, 2690, 2737, 2785, 2831, 2877, 2923, 2968,
3013, 3057, 3100, 3143, 3185, 3227, 3267, 3307, 3347, 3385,
3423, 3460, 3496, 3531, 3565, 3598, 3631, 3662, 3692, 3722,
3750, 3778, 3804, 3829, 3854, 3877, 3899, 3920, 3940, 3958,
3976, 3992, 4007, 4021, 4034, 4046, 4056, 4065, 4073, 4080,
4086, 4090, 4093, 4095, 4095, 4095, 4093, 4090, 4086, 4080,
4073, 4065, 4056, 4046, 4034, 4021, 4007, 3992, 3976, 3958,
3940, 3920, 3899, 3877, 3854, 3829, 3804, 3778, 3750, 3722,
3692, 3662, 3631, 3598, 3565, 3531, 3496, 3460, 3423, 3385,
3347, 3307, 3267, 3227, 3185, 3143, 3100, 3057, 3013, 2968,
2923, 2877, 2831, 2785, 2737, 2690, 2642, 2594, 2545, 2496,
2447, 2398, 2348, 2298, 2248, 2198, 2148, 2098, 2047, 1997,
1947, 1897, 1847, 1797, 1747, 1697, 1648, 1599, 1550, 1501,
1453, 1405, 1358, 1310, 1264, 1218, 1172, 1127, 1082, 1038,
995, 952, 910, 868, 828, 788, 748, 710, 672, 635,
599, 564, 530, 497, 464, 433, 403, 373, 345, 317,
291, 266, 241, 218, 196, 175, 155, 137, 119, 103,
88, 74, 61, 49, 39, 30, 22, 15, 9, 5,
2, 0, 0, 0, 2, 5, 9, 15, 22, 30,
39, 49, 61, 74, 88, 103, 119, 137, 155, 175,
196, 218, 241, 266, 291, 317, 345, 373, 403, 433,
464, 497, 530, 564, 599, 635, 672, 710, 748, 788,
828, 868, 910, 952, 995, 1038, 1082, 1127, 1172, 1218,
1264, 1310, 1358, 1405, 1453, 1501, 1550, 1599, 1648, 1697,
1747, 1797, 1847, 1897, 1947, 1997 };
void Set_Sine12bit(float MAX,float MIN)
{
int i;
float jiaodu=0;
float MID=(MAX+MIN)/2.0; //中间峰值
if(MAX>3.3) MAX=3.3;
else if(MAX<=MIN) MIN=0;
for(i=0;i<256;i++)
{
jiaodu=i*0.0247369; //当i=127时,表示为180度,由于sin()是弧度制,所以需要转换
Sine12bit[i]=((float)sin(jiaodu)*(MAX-MID)+MID)*1241.212; //1241.212是比例,等于4096/3.3
}
}
void Set_Period(u32 value)
{
TIM_ARRPreloadConfig(TIM2,DISABLE);
TIM2->ARR=HZ(value); //更新预装载值
TIM_ARRPreloadConfig(TIM2,ENABLE);
}
void TIM2_Int_Init(u32 Hz)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);//初始化定时器2与6的时钟
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Period =HZ(Hz); //正弦波频率设置
TIM_TimeBaseStructure.TIM_Prescaler =0x0; //没有预分频
TIM_TimeBaseStructure.TIM_ClockDivision =0x0; //时钟不分频 72M
TIM_TimeBaseStructure.TIM_CounterMode =TIM_CounterMode_Up; //增计数
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);//更新TIM2输出触发
}
void DAC_DMA_Config(void)
{
DAC_InitTypeDef DAC_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);//初始化DAC的时钟
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);//初始化DMA2的时钟
GPIO_InitStructure.GPIO_Pin =GPIO_Pin_4 ;//DAC channel1和channel2对应的引脚
GPIO_InitStructure.GPIO_Mode =GPIO_Mode_Out_PP; //推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
DAC_StructInit(&DAC_InitStructure);
DAC_InitStructure.DAC_Trigger =DAC_Trigger_T2_TRGO;//指定DAC1的触发定时器TIM2
DAC_InitStructure.DAC_WaveGeneration =DAC_WaveGeneration_None;//无波形产生
DAC_InitStructure.DAC_OutputBuffer =DAC_OutputBuffer_Enable; //不是能DAC输出缓冲
DAC_Init(DAC_Channel_1, &DAC_InitStructure);//初始化DAC channel1
DAC_Cmd(DAC_Channel_1, ENABLE); //使能DAC channel1
DAC_DMACmd(DAC_Channel_1, ENABLE); //使能DAC Channel1的DMA
DMA_DeInit(DMA2_Channel3); //将DMA配置成默认值
DMA_InitStructure.DMA_PeripheralBaseAddr =DAC_DHR12R1;//指定DMA2通道3的目标地址为DAC1_DHR12R1
DMA_InitStructure.DMA_MemoryBaseAddr =(uint32_t)&Sine12bit;//指定DMA的源地址为数组Sine12bit
DMA_InitStructure.DMA_DIR =DMA_DIR_PeripheralDST;//外设作为数据传输的目的地
DMA_InitStructure.DMA_BufferSize =sizeof(Sine12bit)/2;//DMA缓冲区大小
DMA_InitStructure.DMA_PeripheralInc =DMA_PeripheralInc_Disable;//外设机地址存器不变
DMA_InitStructure.DMA_MemoryInc =DMA_MemoryInc_Enable; //内存地址寄存器递增
DMA_InitStructure.DMA_PeripheralDataSize =DMA_PeripheralDataSize_HalfWord;//外设数据宽度为半字
DMA_InitStructure.DMA_MemoryDataSize =DMA_MemoryDataSize_HalfWord;//内存数据宽度为半字
DMA_InitStructure.DMA_Mode =DMA_Mode_Circular;//工作在循环缓存模式，数据传输数为0时，自动恢复配置初值
DMA_InitStructure.DMA_Priority =DMA_Priority_VeryHigh;//非常高优先级
DMA_InitStructure.DMA_M2M =DMA_M2M_Disable;//通道未被设置成内存到内存模式，与循环模式相对
DMA_Init(DMA2_Channel3, &DMA_InitStructure);//初始化DMA
DMA_Cmd(DMA2_Channel3, ENABLE); //使能DMA的channel3
TIM_Cmd(TIM2, ENABLE); //最后开启TIM2转换
}
文章来源：https://www.cnblogs.com/lifexy/p/8820281.html
