CH32V307_DAC输出正弦波

CH32V307 DAC输出正弦波

CH32V307 DAC输出正弦波

本文介绍使用CH32V307的DAC功能，从输出管脚输出正弦波。

使用到的硬件

CH32V307芯片模块包含2个可配置8/12位数模转换器，其引脚分别位PA4和PA5，作为DAC功能时，分别对应DAC_Channel1和DAC_Channel2两个通道。数据手册中信息如下。

输出程序编写

DDS是控制MCU输出任意波形的常见技术，其实现方法是通过使用查表得方式确定某个时间点DAC的输出电平，设定一个时间间隔，每隔固定时间查询一次表，确定当前输出的DAC的值。具体实现方法是设定一个正弦波DAC数组，开启DMA功能，将数组中的值传递到DAC的输出寄存器中，DMA使用定时器触发从而实现对周期的控制。具体的代码如下：

#include "debug.h"


/* Global define */
#define Num 64

/* Global Variable */
uint32_t DAC_Value[Num]={2048,2248,2447,2642,2831,3013,3185,3347,3496,3631,3750,3854,3940,4007,4056,4086,
4095,4086,4056,4007,3940,3854,3750,3631,3496,3347,3185,3013,2831,2642,2447,2248,
2048,1847,1648,1453,1264,1082,910 ,748 ,599 ,464 ,345 ,241 ,155 ,88  ,39  ,9   ,
0   ,9   ,39  ,88  ,155 ,241 ,345 ,464 ,599 ,748 ,910 ,1082,1264,1453,1648,1847};

uint32_t Dual_DAC_Value[Num];

/*********************************************************************

* @fn      Dac_Init
* 
* @brief   Initializes DAC collection.
* 
* @return  none
  */
  void Dual_Dac_Init(void)
  {
  GPIO_InitTypeDef GPIO_InitStructure={0};
  DAC_InitTypeDef DAC_InitType={0};
  
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE );
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE );
  
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4|GPIO_Pin_5;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
  GPIO_SetBits(GPIOA,GPIO_Pin_4);
  
  DAC_InitType.DAC_Trigger=DAC_Trigger_T4_TRGO;
  DAC_InitType.DAC_WaveGeneration=DAC_WaveGeneration_None;
  DAC_InitType.DAC_LFSRUnmask_TriangleAmplitude=DAC_LFSRUnmask_Bit0;
  DAC_InitType.DAC_OutputBuffer=DAC_OutputBuffer_Disable ;
  DAC_Init(DAC_Channel_1,&DAC_InitType);
  DAC_Init(DAC_Channel_2,&DAC_InitType);
  
  DAC_Cmd(DAC_Channel_1, ENABLE);
  DAC_Cmd(DAC_Channel_2, ENABLE);
  
  DAC_DMACmd(DAC_Channel_1,ENABLE);
  DAC_DMACmd(DAC_Channel_2,ENABLE);
  
  DAC_SetDualChannelData(DAC_Align_12b_R, 0x123,0x321);
  }

/*********************************************************************

* @fn      DAC1_DMA_INIT
* 
* @brief   Initializes DMA of DAC1 collection.
* 
* @return  none
  */
  void Dac_Dma_Init(void)
  {
  DMA_InitTypeDef DMA_InitStructure={0};
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);
  
  DMA_StructInit( &DMA_InitStructure);
  DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(DAC->RD12BDHR);
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&Dual_DAC_Value[0];
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
  DMA_InitStructure.DMA_BufferSize = Num;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
  DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
  
  DMA_Init(DMA2_Channel3, &DMA_InitStructure);
  DMA_Cmd(DMA2_Channel3, ENABLE);
  }

/*********************************************************************

* @fn      Timer4_Init
* 
* @brief   Initializes TIM4
* 
* @return  none
  */
  void Timer4_Init(void)
  {
  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure={0};
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
  
  TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
  TIM_TimeBaseStructure.TIM_Period = 3600-1;
  TIM_TimeBaseStructure.TIM_Prescaler =0;
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
  
  TIM_SelectOutputTrigger(TIM4, TIM_TRGOSource_Update);
  TIM_Cmd(TIM4, ENABLE);
  }

/*********************************************************************

* @fn      main
* 
* @brief   Main program.
* 
* @return  none
  */
  int main(void)
  {
  uint8_t i=0;
  SystemCoreClockUpdate();
  Delay_Init();
  USART_Printf_Init(115200);	
  printf("SystemClk:%d\\\\r\\\\n",SystemCoreClock);
  printf( "ChipID:%08x\\\\r\\\\n", DBGMCU_GetCHIPID() );
  printf("Dual DAC Generation Test\\\\r\\\\n");
  for(i=0;i<Num;i++)
  {
  Dual_DAC_Value[i]=(DAC_Value[i]<<16) + DAC_Value[i];
  printf("0x%08x\\\\r\\\\n",Dual_DAC_Value[i]);
  }
  
  Dual_Dac_Init();
  Dac_Dma_Init();
  Timer4_Init();
  while(1)
  {
  printf("CNT=%d\\\\r\\\\n",TIM4->CNT);
  printf("RD12BDHR=0x%04x\\\\r\\\\n",DAC->RD12BDHR);
  printf("DOR1=0x%04x\\\\r\\\\n",DAC->DOR1);
  printf("DOR2=0x%04x\\\\r\\\\n",DAC->DOR2);
  Delay_Ms(500);
  }
  }