STM32模拟开门狗中断，设置高低电压阈值

当被ADC 转换的模拟电压低于低阈值或者高于高阈值时，就会产生中断，前提是我们开启了模拟看门狗中断，其中低阈值和高阈值由ADC_LTR 和ADC_HTR 设置。例如我们设置高阈值是2.5V，那么模拟电压超过2.5V 的时候，就会产生模拟看门狗中断，反之低阈值也一样。

#include "bsp_adc.h"

__IO uint16_t ADC_ConvertedValue;


/**
  * @brief  ADC GPIO ³õʼ»¯
  * @param  ÎÞ
  * @retval ÎÞ
  */
static void ADCx_GPIO_Config(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	
	// ´ò¿ª ADC IO¶Ë¿ÚʱÖÓ
	ADC_GPIO_APBxClock_FUN ( ADC_GPIO_CLK, ENABLE );
	
	// ÅäÖà ADC IO Òý½Åģʽ
	// ±ØÐëΪģÄâÊäÈë
	GPIO_InitStructure.GPIO_Pin = ADC_PIN;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
	
	// ³õʼ»¯ ADC IO
	GPIO_Init(ADC_PORT, &GPIO_InitStructure);				
}

/**
  * @brief  ADC Watchdog ³õʼ»¯
  * @param  ÎÞ
  * @retval ÎÞ
  */
static void ADC_WatchdogConfig(void)
{
  ADC_AnalogWatchdogSingleChannelConfig(ADCx, ADC_CHANNEL);
  ADC_AnalogWatchdogThresholdsConfig(ADCx, 0x0350, 0x0200);
  ADC_AnalogWatchdogCmd(ADCx, ADC_AnalogWatchdog_SingleRegEnable);
}

/**
  * @brief  ÅäÖÃADC¹¤×÷ģʽ
  * @param  ÎÞ
  * @retval ÎÞ
  */
static void ADCx_Mode_Config(void)
{
	ADC_InitTypeDef ADC_InitStructure;	

	// ´ò¿ªADCʱÖÓ
	ADC_APBxClock_FUN (ADC_CLK, ENABLE );
	
	// ADC ģʽÅäÖÃ
	// ֻʹÓÃÒ»¸öADC£¬ÊôÓÚ¶ÀÁ¢Ä£Ê½
	ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
	
	// ½ûֹɨÃèģʽ£¬¶àͨµÀ²ÅÒª£¬µ¥Í¨µÀ²»ÐèÒª
	ADC_InitStructure.ADC_ScanConvMode = DISABLE ; 

	// Á¬Ðøת»»Ä£Ê½
	ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;

	// ²»ÓÃÍⲿ´¥·¢×ª»»£¬Èí¼þ¿ªÆô¼´¿É
	ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;

	// ת»»½á¹ûÓÒ¶ÔÆë
	ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
	
	// ת»»Í¨µÀ1¸ö
	ADC_InitStructure.ADC_NbrOfChannel = 1;	
		
	// ³õʼ»¯ADC
	ADC_Init(ADCx, &ADC_InitStructure);
	
	// ÅäÖÃADCʱÖÓΪPCLK2µÄ8·ÖƵ£¬¼´9MHz
	RCC_ADCCLKConfig(RCC_PCLK2_Div8); 
	
	// ÅäÖà ADC ͨµÀת»»Ë³ÐòºÍ²ÉÑùʱ¼ä
	ADC_RegularChannelConfig(ADCx, ADC_CHANNEL, 1, 
	                         ADC_SampleTime_239Cycles5);   //ADC_SampleTime_239Cycles5  ADC_SampleTime_55Cycles5
	
	// ADC ת»»½áÊø²úÉúÖжϣ¬ÔÚÖжϷþÎñ³ÌÐòÖжÁȡת»»Öµ
	//ADC_ITConfig(ADCx, ADC_IT_EOC, ENABLE);
	
	ADC_WatchdogConfig();
	
	// ¿ªÆôADC £¬²¢¿ªÊ¼×ª»»
	ADC_Cmd(ADCx, ENABLE);
	
	// ³õʼ»¯ADC У׼¼Ä´æÆ÷  
	ADC_ResetCalibration(ADCx);
	// µÈ´ýУ׼¼Ä´æÆ÷³õʼ»¯Íê³É
	while(ADC_GetResetCalibrationStatus(ADCx));
	
	// ADC¿ªÊ¼Ð£×¼
	ADC_StartCalibration(ADCx);
	// µÈ´ýУ׼Íê³É
	while(ADC_GetCalibrationStatus(ADCx));

	//Ä£Äâ¿´ÃŹ·²úÉúÖжϣ¬ÔÚÖжϷþÎñ³ÌÐòÖжÁȡת»»Öµ
	ADC_ITConfig(ADCx, ADC_IT_AWD, ENABLE);
	
	// ÓÉÓÚûÓвÉÓÃÍⲿ´¥·¢£¬ËùÒÔʹÓÃÈí¼þ´¥·¢ADCת»» 
	ADC_SoftwareStartConvCmd(ADCx, ENABLE);
}

static void ADC_NVIC_Config(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;
	// ÓÅÏȼ¶·Ö×é
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

  // ÅäÖÃÖжÏÓÅÏȼ¶
  NVIC_InitStructure.NVIC_IRQChannel = ADC_IRQ;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

/**
  * @brief  ADC³õʼ»¯
  * @param  ÎÞ
  * @retval ÎÞ
  */
void ADCx_Init(void)
{
	ADCx_GPIO_Config();
	ADCx_Mode_Config();
	ADC_NVIC_Config();
}
/*********************************************END OF FILE**********************/

void ADC_IRQHandler(void)
{	
	printf("ADC AWD is happened 1.\r\n");
	
	/***
	EOCÖжϷ½Ê½
	printf("\r\n ----ADC_IRQHandler----\r\n");
	if (ADC_GetITStatus(ADCx,ADC_IT_EOC)==SET) 
	{
		// ¶ÁÈ¡ADCµÄת»»Öµ
		ADC_ConvertedValue = ADC_GetConversionValue(ADCx);
	}
	ADC_ClearITPendingBit(ADCx,ADC_IT_EOC);
	***/
	ADC_ITConfig(ADCx, ADC_IT_AWD, DISABLE);
	
  if(SET == ADC_GetFlagStatus(ADCx, ADC_FLAG_AWD))
  {
    ADC_ClearFlag(ADCx, ADC_FLAG_AWD);
    ADC_ClearITPendingBit(ADCx, ADC_IT_AWD);
    printf("ADC AWD is happened 2.\r\n");
		ADC_ConvertedValue = ADC_GetConversionValue(ADCx);
   }
}

int main(void)
{	
	// ÅäÖô®¿Ú
	USART_Config();
	
	// ADC ³õʼ»¯
	ADCx_Init();
	
	printf("\r\n ----ÕâÊÇÒ»¸öADCµ¥Í¨µÀÖж϶ÁȡʵÑé----\r\n");
	
	while (1)
	{
		ADC_ConvertedValueLocal =(float) ADC_ConvertedValue/4096*3.3; 
	
		printf("\r\n The current AD value = 0x%04X \r\n", 
		       ADC_ConvertedValue); 
		printf("\r\n The current AD value = %f V \r\n",
		       ADC_ConvertedValueLocal); 
		printf("\r\n\r\n");

		ADC_ITConfig(ADCx, ADC_IT_AWD, ENABLE);
		Delay(0xffffee);  
	}
}

ADC_AnalogWatchdogThresholdsConfig(ADCx, 0x0350, 0x0200);

设置电压高低电平阈值，0xFFF对应3.3V，最高模拟电压值。这里高电平是（0x350/0xFFF）*3.3V，低电平是（0x200/0xFFF）*3.3V。

当采样模拟电压高于高电平阈值，低于低电平的时候阈值，就会产生中断。