main.c

/**
  ******************************************************************************
  * @file    Project/STM32F2xx_StdPeriph_Template/main.c 
  * @author  MCD Application Team
  * @version V1.1.0
  * @date    13-April-2012
  * @brief   Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; COPYRIGHT 2012 STMicroelectronics</center></h2>
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
  */ 

/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "LCD_disp.h"

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
static __IO uint32_t TimingDelay;

void DAC1_Config(void);
void Dac1_Set_Vol(uint16_t vol);

/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/**
  * @brief  Main program.
  * @param  None
  * @retval None
  */
int main(void)
{
  uint32_t line = 0;
  uint32_t num = 0;
  uint32_t data = 1;
  RCC_ClocksTypeDef RCC_Clocks;
  GPIO_InitTypeDef  GPIO_Init_s;
  
  /* 配置SysTick为1ms */
  RCC_GetClocksFreq(&RCC_Clocks);
  SysTick_Config(RCC_Clocks.HCLK_Frequency / 1000);
  
  /* 使能GPIOE端口时钟 */
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
  
  /* 配置LED管脚 */
  GPIO_Init_s.GPIO_Pin = GPIO_Pin_4;
  GPIO_Init_s.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_Init_s.GPIO_OType = GPIO_OType_PP;
  GPIO_Init_s.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init_s.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_Init(GPIOE, &GPIO_Init_s);
  
  GPIO_SetBits(GPIOE,GPIO_Pin_4);//熄灭LED灯
  
  DAC1_Config();
  
  LCD_Init();
  
  LCD_ShowString(0,0,"DAC set 0");
  
  while (1)
  {
    GPIO_SetBits(GPIOE,GPIO_Pin_4);  //熄灭LED灯
    Dac1_Set_Vol(1200);
    LCD_ShowString(0,0,"DAC OUT 1.2V");
    Delay(500);                      //延时500ms
    GPIO_ResetBits(GPIOE,GPIO_Pin_4);//点亮LED灯
    Dac1_Set_Vol(3000);
    LCD_ShowString(0,0,"DAC OUT 3.0V");
    Delay(500);                      //延时500ms
  }
}

//设置通道1输出电压
//vol:0~3300,代表0~3.3V
void Dac1_Set_Vol(uint16_t vol)
{
  double temp=vol;
  temp/=1000;
  temp=temp*4096/3.3;
  DAC_SetChannel1Data(DAC_Align_12b_R,temp);//12位右对齐数据格式设置DAC值
}
void DAC1_Config(void)
{
  DAC_InitTypeDef  DAC_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;
  
  /* DMA1 clock and GPIOA clock enable (to be used with DAC) */
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
  
  /* DAC Periph clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
  
  /* DAC channel 1 & 2 (DAC_OUT1 = PA.4)(DAC_OUT2 = PA.5) configuration */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
  
   /* DAC channel2 Configuration */
  DAC_InitStructure.DAC_Trigger = DAC_Trigger_None;
  DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
  DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bit0;
  DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Disable;
  DAC_Init(DAC_Channel_1, &DAC_InitStructure);

  /* Enable DAC Channel2 */
  DAC_Cmd(DAC_Channel_1, ENABLE);
}
/**
  * @brief  Inserts a delay time.
  * @param  nTime: specifies the delay time length, in 10 ms.
  * @retval None
  */
void Delay(__IO uint32_t nTime)
{
  TimingDelay = nTime;

  while(TimingDelay != 0);
}

/**
  * @brief  Decrements the TimingDelay variable.
  * @param  None
  * @retval None
  */
void TimingDelay_Decrement(void)
{
  if (TimingDelay != 0x00)
  { 
    TimingDelay--;
  }
}
//微秒级的延时
void delay_us(uint32_t delay_us)
{    
  volatile unsigned int num;
  volatile unsigned int t;

  
  for (num = 0; num < delay_us; num++)
  {
    t = 11;
    while (t != 0)
    {
      t--;
    }
  }
}
//毫秒级的延时
void delay_ms(uint16_t delay_ms)
{    
  volatile unsigned int num;
  for (num = 0; num < delay_ms; num++)
  {
    delay_us(1000);
  }
}

/*120Mhz时钟时，当ulCount为1时，函数耗时3个时钟，延时=3*1/120us=1/40us*/
/*
SystemCoreClock=120000000

us级延时,延时n微秒
SysCtlDelay(n*(SystemCoreClock/3000000));

ms级延时,延时n毫秒
SysCtlDelay(n*(SystemCoreClock/3000));

m级延时,延时n秒
SysCtlDelay(n*(SystemCoreClock/3));
*/

#if defined   (__CC_ARM) /*!< ARM Compiler */
__asm void
SysCtlDelay(unsigned long ulCount)
{
    subs    r0, #1;
    bne     SysCtlDelay;
    bx      lr;
}
#elif defined ( __ICCARM__ ) /*!< IAR Compiler */
void
SysCtlDelay(unsigned long ulCount)
{
    __asm("    subs    r0, #1\n"
       "    bne.n   SysCtlDelay\n"
       "    bx      lr");
}

#elif defined (__GNUC__) /*!< GNU Compiler */
void __attribute__((naked))
SysCtlDelay(unsigned long ulCount)
{
    __asm("    subs    r0, #1\n"
       "    bne     SysCtlDelay\n"
       "    bx      lr");
}

#elif defined  (__TASKING__) /*!< TASKING Compiler */                           
/*无*/
#endif /* __CC_ARM */


/**
  * @}
  */


/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/