u16 SineWave_Value[256];
/********正弦波输出表***********/
//cycle :波形表的位数 (0~256) 8位
//Um :输出电压的峰值(0~1.5)
/*******************************/
void SineWave_Data( u16 cycle ,u16 *D,float Um)
{
u16 i;
for( i=0;i<cycle;i++)
{
D[i]=(u16)((Um*sin(( 1.0*i/(cycle-1))*2*PI)+Um)*4095/3.3);//+Um向上平移至0~2Um; 2^12=4096; 2^8=256; 单片机电压3.3V
}
}
/****************初始化引脚******************/
//----------------PA4输出
void SineWave_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //开时钟
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN; //模拟输出模式
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //输出速率
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 ; //选择引脚 PA4
GPIO_SetBits(GPIOA,GPIO_Pin_4) ; //拉高输出
GPIO_Init(GPIOA, &GPIO_InitStructure); //初始化
}
/******************DAC初始化ˉ*************************/
void SineWave_DAC_Config( void)
{
DAC_InitTypeDef DAC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);//开DAC时钟
/**************DAC结构初始化*******************/
//使能DAC通道1和通道1的DMA
DAC_StructInit(&DAC_InitStructure);
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;//不产生波形
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Disable; //不使能输出缓存
DAC_InitStructure.DAC_Trigger = DAC_Trigger_T2_TRGO; //DAC触发为定时器2触发
DAC_Init(DAC_Channel_1, &DAC_InitStructure); //初始化
DAC_Cmd(DAC_Channel_1, ENABLE); //使能DAC的通道1
DAC_DMACmd(DAC_Channel_1, ENABLE); //使能DAC通道1的DMA
}
/*********定时器初始化************/
//定时器2初始化
void SineWave_TIM_Config(u32 Wave1_Fre)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); //开TIM2时钟
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Prescaler = 0x0; //不预分频
TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; //不分频<br>
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数
TIM_TimeBaseStructure.TIM_Period = Wave1_Fre; //设置输出频率
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update); //设置TIME输出触发为更新模式
}
/****************DMA配置******************/
//DMA2配置
void SineWave_DMA_Config(void)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE); //开启DMA2时钟
DMA_StructInit( &DMA_InitStructure); //DMA结构体初始化
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST; //从寄存器读数据
DMA_InitStructure.DMA_BufferSize = 256; //寄存器大小
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_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;//宽度为半字
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;//宽度为半字
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh; //优先级非常高
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //关闭内存到内存模式
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; //循环发送模式
DMA_InitStructure.DMA_PeripheralBaseAddr = DAC_DHR12R1; //外设地址为DAC通道1的地址
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)SineWave_Value; //波形数据表内存地址
DMA_Init(DMA2_Channel3, &DMA_InitStructure); //初始化
DMA_Cmd(DMA2_Channel3, ENABLE); //使能DMA2的通道3
}
/**********正弦波初始化**********************/
//Wave1_Fre: 频率值（0~60 000)Hz
//Um : 电压峰值（0.0~1.5）V
/*******************************************/
void SineWave_Init(u16 Wave1_Fre,float Um)
{
u32 f1;
f1=(u32)(72000000/sizeof(SineWave_Value)*2/Wave1_Fre);//计算频率 72MHz
SineWave_Data(256,SineWave_Value,Um); //生成输出正弦波的波形表
SineWave_GPIO_Config(); //初始化io
SineWave_TIM_Config(f1); //初始化定时器
SineWave_DAC_Config(); //配置DAC
SineWave_DMA_Config(); //配置DMA
TIM_Cmd(TIM2, ENABLE); //开启定时器
}
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