DHT11代码无阻塞读取

2502_91690177

56人浏览 · 2026-06-11 10:10:39

2502_91690177 · 2026-06-11 10:10:39 发布

以下是DHT11.c文件，包含阻塞和非阻塞

#include "DHT11.h" 

static void DHT11_Mode_IPU(void);
static void DHT11_Mode_Out_PP(void);
DHT11_Data_TypeDef DHT11_Data;
uint8_t DHT11_Flag = 1;   
uint8_t temp;

void DHT11_Init ( void ) 
{

 RCC_APB2PeriphClockCmd(DHT11_GPIO_CLK, ENABLE);
	DHT11_Mode_Out_PP();
	DHT11_W_DATA(DHT11_DATA_SET); 
}


static void DHT11_Mode_IPU(void)   
{
	GPIO_InitTypeDef GPIO_InitStruct = {0};
	GPIO_InitStruct.GPIO_Pin = DHT11_GPIO_PIN;	
	GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU; 
	GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;	
	GPIO_Init(DHT11_GPIO_PORT, &GPIO_InitStruct);					 
}


static void DHT11_Mode_Out_PP(void)  
{

	GPIO_InitTypeDef GPIO_InitStruct = {0};
	GPIO_InitStruct.GPIO_Pin = DHT11_GPIO_PIN;	
	GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP; 
	GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;	
	GPIO_Init(DHT11_GPIO_PORT, &GPIO_InitStruct);		
}



static uint8_t DHT11_ReadByte ( void )   
{
	uint8_t i, temp=0;
	
	for(i=0;i<8;i++)    
	{	 

		while(DHT11_R_DATA==DHT11_DATA_RESET);


		Delay_us(40); 	   	  

		if(DHT11_R_DATA==DHT11_DATA_SET)
		{
	
			while(DHT11_R_DATA==DHT11_DATA_SET);

			temp|=(uint8_t)(0x01<<(7-i)); 
		}
		else	
		{			   
			temp&=(uint8_t)~(0x01<<(7-i)); 
		}
	}
	return temp;
}



uint8_t DHT11_Read_TempAndHumidity(DHT11_Data_TypeDef *DHT11_Data)  
{  
  uint8_t temp;
  uint16_t humi_temp;
  

	DHT11_Mode_Out_PP();

	DHT11_W_DATA(DHT11_DATA_RESET);

	Delay_ms(20);


	DHT11_W_DATA(DHT11_DATA_SET); 

	Delay_us(30);  

 
	DHT11_Mode_IPU();
	Delay_us(30);  
 
	if(DHT11_R_DATA==DHT11_DATA_RESET)     
	{
 
    while(DHT11_R_DATA==DHT11_DATA_RESET);


    while(DHT11_R_DATA==DHT11_DATA_SET);

 
    DHT11_Data->humi_high8bit= DHT11_ReadByte();
    DHT11_Data->humi_low8bit = DHT11_ReadByte();
    DHT11_Data->temp_high8bit= DHT11_ReadByte();
    DHT11_Data->temp_low8bit = DHT11_ReadByte();
    DHT11_Data->check_sum    = DHT11_ReadByte();


    DHT11_Mode_Out_PP();

    DHT11_W_DATA(DHT11_DATA_SET);
    
    humi_temp=DHT11_Data->humi_high8bit*100+DHT11_Data->humi_low8bit;
    DHT11_Data->humidity =(float)humi_temp/100;
    
    humi_temp=DHT11_Data->temp_high8bit*100+DHT11_Data->temp_low8bit;
    DHT11_Data->temperature=(float)humi_temp/100;    
    
    temp = DHT11_Data->humi_high8bit + DHT11_Data->humi_low8bit + 
           DHT11_Data->temp_high8bit+ DHT11_Data->temp_low8bit;
    if(DHT11_Data->check_sum==temp)
    { 
      return 1;
    }
    else return -1;
	}	
	else
		return -1;
}

uint8_t DHT11_GetFlag()   
{
	if(DHT11_Flag == 1)
	{
		return 1;
	}
	return 0;
}

void DHT11_GetVlaue(DHT11_Data_TypeDef *DHT11_Data)  
{
	uint16_t humi_temp;
		
	DHT11_Data->humi_high8bit= DHT11_Data->buf[0];
    DHT11_Data->humi_low8bit = DHT11_Data->buf[1];
    DHT11_Data->temp_high8bit= DHT11_Data->buf[2];
    DHT11_Data->temp_low8bit = DHT11_Data->buf[3];
    DHT11_Data->check_sum    = DHT11_Data->buf[4];
	
	humi_temp=DHT11_Data->humi_high8bit*100+DHT11_Data->humi_low8bit;
	DHT11_Data->humidity =(float)humi_temp/100;
	
	humi_temp=DHT11_Data->temp_high8bit*100+DHT11_Data->temp_low8bit;
	if(DHT11_Data->temp_low8bit & (0x01<<8))
	{
		DHT11_Data->temperature = -(float)humi_temp/100;
	}
	else
	{
		DHT11_Data->temperature = (float)humi_temp/100; 
	}
    DHT11_Flag = 0;
}


uint8_t DHT11_Tick(DHT11_Data_TypeDef *DHT11_Data)    
{
	static uint8_t DHT11_S = 0;
	static uint8_t i = 0;
	static uint8_t j = 0;
	static uint16_t time = 0;
	static uint16_t timeout = 0;
	if(time > 0)
	{
		time--;
		return 0;
	}
	timeout++;
	if(DHT11_S == 0)
	{
		if(DHT11_Flag == 0)
		{
			DHT11_Mode_Out_PP();
			DHT11_W_DATA(DHT11_DATA_RESET);
			time = 2000;
			DHT11_S = 1;
			timeout = 0;
		}
	}
	else if(DHT11_S == 1)
	{
			DHT11_W_DATA(DHT11_DATA_SET);
			time = 3;
			DHT11_S = 2;
			timeout = 0;
	}
	else if(DHT11_S == 2)
	{
			DHT11_Mode_IPU();
			if(DHT11_R_DATA==DHT11_DATA_RESET)
				{
					DHT11_S = 3;
					timeout = 0;
				}
			else if(timeout > 10)
			{
				DHT11_S = 0;
				DHT11_Mode_Out_PP();
				DHT11_W_DATA(DHT11_DATA_SET);
				timeout = 0;
			}				

	}
	else if(DHT11_S == 3)
	{
		if((DHT11_R_DATA==DHT11_DATA_SET))
		{
			DHT11_S = 4;
			timeout = 0;
		}
		else if(timeout > 10)
			{
				DHT11_S = 0;
				DHT11_Mode_Out_PP();
				DHT11_W_DATA(DHT11_DATA_SET);
				timeout = 0;
			}	
	}
	
	else if(DHT11_S == 4)
	{
		if((DHT11_R_DATA==DHT11_DATA_RESET))
		{
			DHT11_S = 5;
			timeout = 0;
		}
		else if(timeout > 10)
			{
				DHT11_S = 0;
				DHT11_Mode_Out_PP();
				DHT11_W_DATA(DHT11_DATA_SET);
				timeout = 0;
			}
	}
	else if(DHT11_S == 5)
	{
		if((DHT11_R_DATA==DHT11_DATA_SET))
		{
			DHT11_S = 6;
			time = 4;
			timeout = 0;
		}
		else if(timeout > 10)
			{
				DHT11_S = 0;
				DHT11_Mode_Out_PP();
				DHT11_W_DATA(DHT11_DATA_SET);
				timeout = 0;
			}	
	}
	
	else if(DHT11_S == 6)
	{
			if(DHT11_R_DATA==DHT11_DATA_SET)
			{
				temp|=(uint8_t)(0x01<<(7-i));
			}
				i++;
			if(i == 8)
			{
				i = 0;
				
				DHT11_Data->buf[j] = temp;
				j++;
				temp = 0;
				if(j == 5)
				{
					j = 0;
					uint8_t sum = DHT11_Data->buf[0] + DHT11_Data->buf[1] + DHT11_Data->buf[2] + DHT11_Data->buf[3];
					if(sum == DHT11_Data->buf[4])
					{
						DHT11_Flag = 1;
						
						
					}
					else
					{
						DHT11_Flag = 0;
					}
					DHT11_Mode_Out_PP();
          DHT11_W_DATA(DHT11_DATA_SET);
					DHT11_S = 0;
					timeout = 0;
				}
			}
			DHT11_S = 4;
			timeout = 0;
			
	}
	return DHT11_S;
}

DHT11.h

#ifndef __DHT11_H__
#define __DHT11_H__

#include "stm32f10x.h"  
#include "Delay.h"


typedef struct
{
	uint8_t  humi_high8bit;	
	uint8_t  humi_low8bit;	
	uint8_t  temp_high8bit;	
	uint8_t  temp_low8bit;	
	uint8_t  check_sum;	 	 
	uint8_t  buf[5];
  float    humidity;      
  float    temperature;
	
} DHT11_Data_TypeDef;


#define DHT11_GPIO_PORT  GPIOG
#define DHT11_GPIO_PIN   GPIO_Pin_11
#define DHT11_GPIO_CLK   RCC_APB2Periph_GPIOG

#define DHT11_DATA_SET     1
#define DHT11_DATA_RESET   0


#define DHT11_W_DATA(x)		GPIO_WriteBit(DHT11_GPIO_PORT, DHT11_GPIO_PIN, (BitAction)(x))
#define DHT11_R_DATA      GPIO_ReadInputDataBit(DHT11_GPIO_PORT,DHT11_GPIO_PIN)

extern DHT11_Data_TypeDef DHT11_Data;

void DHT11_Init( void );
uint8_t DHT11_Read_TempAndHumidity(DHT11_Data_TypeDef * DHT11_Data);
uint8_t DHT11_GetFlag();
void DHT11_GetVlaue(DHT11_Data_TypeDef *DHT11_Data);
uint8_t DHT11_Tick(DHT11_Data_TypeDef *DHT11_Data);

#endif

使用说明

带阻塞读取 main.c

int main(void) 
{ 
	Serial_Init();
	DHT11_Init();
	
	while (1) 
	{ 
			DHT11_Read_TempAndHumidity(&DHT11_Data);
			Serial_Printf("当前温度：%.1f,当前湿度：%.1f\r\n",DHT11_Data.temperature,DHT11_Data.humidity);
		Delay_ms(1000);
	} 
}

无阻塞读取 main.c

int main(void) 
{ 
	MY_Tim2_Init(10,72);   //10us
	Serial_Init();
	DHT11_Init();
	
	while (1) 
	{ 
			if(DHT11_GetFlag() == 1)
			{
				DHT11_GetVlaue(&DHT11_Data);
				Serial_Printf("当前温度：%.1f,当前湿度：%.1f\r\n",DHT11_Data.temperature,DHT11_Data.humidity);
			}
			Delay_ms(1000);
	} 
} 


void TIM2_IRQHandler(void)
{
	if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET)
	{
		DHT11_Tick(&DHT11_Data);
		TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
	}
}

注意事项

1. DHT11_Read_TempAndHumidity函数中的Delay延时函数一定要是系统定时器实现的精确延时，否则可能会读取不到数据。

2. DHT11_Tick函数需要每10us秒执行一次，可以放在定时器中断中实现。

作者声明

代码中有许多冗余的地方，欢迎各位指正修改。