IntelligentPiggery/stm32/HARDWARE/DHT11/dht11.c

#include "dht11.h"
#include "delay.h"

void DHT11_IO_IN(void)
{
	GPIO_InitTypeDef  GPIO_InitStructure;
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);	 //ʹ<EFBFBD><EFBFBD>PB<EFBFBD>˿<EFBFBD>ʱ<EFBFBD><EFBFBD>
	
 	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;				 //PG11<EFBFBD>˿<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
 	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; 		 //
 	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 	GPIO_Init(GPIOB, &GPIO_InitStructure);				 //<EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD>IO<EFBFBD><EFBFBD>
}

void DHT11_IO_OUT(void)
{
	GPIO_InitTypeDef  GPIO_InitStructure;
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);	 //ʹ<EFBFBD><EFBFBD>PB<EFBFBD>˿<EFBFBD>ʱ<EFBFBD><EFBFBD>
	
 	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;				 //PG11<EFBFBD>˿<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
 	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; 		 //
 	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 	GPIO_Init(GPIOB, &GPIO_InitStructure);				 //<EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD>IO<EFBFBD><EFBFBD>
}
      
//<EFBFBD><EFBFBD>λDHT11
void DHT11_Rst(void)	   
{                 
	DHT11_IO_OUT(); 	//SET OUTPUT
    DHT11_DQ_OUT=0; 	//<EFBFBD><EFBFBD><EFBFBD><EFBFBD>DQ54<EFBFBD><EFBFBD>ˮ<EFBFBD><EFBFBD>        
    delay_ms(20);    	//<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>18ms
    DHT11_DQ_OUT=1; 	//DQ=1 
	delay_us(30);     	//<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>20~40us
}
//<EFBFBD>ȴ<EFBFBD>DHT11<EFBFBD>Ļ<EFBFBD>Ӧ
//<EFBFBD><EFBFBD><EFBFBD><EFBFBD>1:δ<EFBFBD><EFBFBD><EFBFBD>⵽DHT11<EFBFBD>Ĵ<EFBFBD><EFBFBD><EFBFBD>
//<EFBFBD><EFBFBD><EFBFBD><EFBFBD>0:<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
u8 DHT11_Check(void) 	   
{   
	u8 retry=0;
	DHT11_IO_IN();//SET INPUT	 
    while (DHT11_DQ_IN&&retry<100)//DHT11<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>40~80us
	{
		retry++;
		delay_us(1);
	};	 
	if(retry>=100)return 1;
	else retry=0;
    while (!DHT11_DQ_IN&&retry<100)//DHT11<EFBFBD><EFBFBD><EFBFBD>ͺ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>40~80us
	{
		retry++;
		delay_us(1);
	};
	if(retry>=100)return 1;	    
	return 0;
}
//<EFBFBD><EFBFBD>DHT11<EFBFBD><EFBFBD>ȡһ<EFBFBD><EFBFBD>λ
//<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><EFBFBD>1/0
u8 DHT11_Read_Bit(void) 			 
{
 	u8 retry=0;
	while(DHT11_DQ_IN&&retry<100)//<EFBFBD>ȴ<EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>͵<EFBFBD>ƽ
	{
		retry++;
		delay_us(1);
	}
	retry=0;
	while(!DHT11_DQ_IN&&retry<100)//<EFBFBD>ȴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߵ<EFBFBD>ƽ
	{
		retry++;
		delay_us(1);
	}
	delay_us(40);//<EFBFBD>ȴ<EFBFBD>40us
	if(DHT11_DQ_IN)return 1;
	else return 0;		   
}
//<EFBFBD><EFBFBD>DHT11<EFBFBD><EFBFBD>ȡһ<EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD>
//<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
u8 DHT11_Read_Byte(void)    
{        
    u8 i,dat;
    dat=0;
	for (i=0;i<8;i++) 
	{
   		dat<<=1; 
	    dat|=DHT11_Read_Bit();
    }						    
    return dat;
}
//<EFBFBD><EFBFBD>DHT11<EFBFBD><EFBFBD>ȡһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
//temp:<EFBFBD>¶<EFBFBD>ֵ(<EFBFBD><EFBFBD>Χ:0~50<EFBFBD><EFBFBD>)
//humi:ʪ<EFBFBD><EFBFBD>ֵ(<EFBFBD><EFBFBD>Χ:20%~90%)
//<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><EFBFBD>0,<EFBFBD><EFBFBD><EFBFBD><EFBFBD>;1,<EFBFBD><EFBFBD>ȡʧ<EFBFBD><EFBFBD>
u8 DHT11_Read_Data(u8 *temp,u8 *humi)    
{        
 	u8 buf[5];
	u8 i;
	DHT11_Rst();
	if(DHT11_Check()==0)
	{
		for(i=0;i<5;i++)//<EFBFBD><EFBFBD>ȡ40λ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
		{
			buf[i]=DHT11_Read_Byte();
		}
		if((buf[0]+buf[1]+buf[2]+buf[3])==buf[4])
		{
			*humi=buf[0];
			*temp=buf[2];
		}
	}else return 1;
	return 0;	    
}
//<EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD>DHT11<EFBFBD><EFBFBD>IO<EFBFBD><EFBFBD> DQ ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>DHT11<EFBFBD>Ĵ<EFBFBD><EFBFBD><EFBFBD>
//<EFBFBD><EFBFBD><EFBFBD><EFBFBD>1:<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
//<EFBFBD><EFBFBD><EFBFBD><EFBFBD>0:<EFBFBD><EFBFBD><EFBFBD><EFBFBD>    	 
u8 DHT11_Init(void)
{	 
 	GPIO_InitTypeDef  GPIO_InitStructure;
 	
 	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);	 //ʹ<EFBFBD><EFBFBD>PB<EFBFBD>˿<EFBFBD>ʱ<EFBFBD><EFBFBD>
	
 	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;				 //PG11<EFBFBD>˿<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
 	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; 		 //<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
 	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 	GPIO_Init(GPIOB, &GPIO_InitStructure);				 //<EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD>IO<EFBFBD><EFBFBD>
 	GPIO_SetBits(GPIOB,GPIO_Pin_15);						 //PG11 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
			    
	DHT11_Rst();  //<EFBFBD><EFBFBD>λDHT11
	return DHT11_Check();//<EFBFBD>ȴ<EFBFBD>DHT11<EFBFBD>Ļ<EFBFBD>Ӧ
}