bossay_release_out/app/A21_Agriculture/src/DHT11.c

#include "DHT11.h"
#include "hi_time.h"

void GPIO_mode_out()
{
    IoTGpioInit(DHT11_DQ_GPIO);
    IoTGpioSetFunc(DHT11_DQ_GPIO, IOT_GPIO_FUNC_GPIO_13_GPIO);
    IoTGpioSetDir(DHT11_DQ_GPIO, IOT_GPIO_DIR_OUT); // 设置为输出模式
}

void GPIO_mode_in()
{
    IoTGpioInit(DHT11_DQ_GPIO);
    IoTGpioSetFunc(DHT11_DQ_GPIO, IOT_GPIO_FUNC_GPIO_13_GPIO);
    IoTGpioSetDir(DHT11_DQ_GPIO, IOT_GPIO_DIR_IN); // 设置为输入模式

}

static uint8_t DHT11_DQ_IN(void)
{
	IotGpioValue temp = {0};
    IoTGpioGetInputVal(DHT11_DQ_GPIO,&temp);
    return temp;
}

//Reset DHT11
void DHT11_Rst(void)	   
{                 
    GPIO_mode_out(); 	//SET OUTPUT
    DHT11_DQ_OUT_OFF; 	//GPIOA.0=0
    osDelay(2);    	//Pull down Least 18ms
    DHT11_DQ_OUT_ON; 	//GPIOA.0=1 
    hi_udelay(30);     	//Pull up 20~40us
}

uint8_t DHT11_Check(void) 	   
{   
	uint8_t retry=0;
	GPIO_mode_in();//SET INPUT	 
    while (DHT11_DQ_IN()&&retry<100)//DHT11 Pull down 40~80us
	{
		retry++;
		hi_udelay(1);
	};	 
	if(retry>=100)
		return 1;
	else 
		retry=0;
    while (!DHT11_DQ_IN()&&retry<100)//DHT11 Pull up 40~80us
	{
		retry++;
		hi_udelay(1);
	};
	if(retry>=100)
		return 1;//chack error	    
	return 0;
}

uint8_t DHT11_Read_Bit(void) 			 
{
 	uint8_t retry=0;
	while(DHT11_DQ_IN()&&retry<100)//wait become Low level
	{
		retry++;
		hi_udelay(1);
	}
	retry=0;
	while(!DHT11_DQ_IN()&&retry<100)//wait become High level
	{
		retry++;
		hi_udelay(1);
	}
	hi_udelay(50);//wait 40us
	if(DHT11_DQ_IN())
		return 1;
	else 
		return 0;		   
}

uint8_t DHT11_Read_Byte(void)    
{        
    uint8_t i,dat;
    dat=0;
	for (i=0;i<8;i++) 
	{
   		dat<<=1; 
	    dat|=DHT11_Read_Bit();
    }						    
    return dat;
}

uint8_t DHT11_Read_Data(uint8_t *temperature,uint8_t *humidity)    
{        
 	uint8_t buf[5];
	uint8_t i;
	DHT11_Rst();
	if(DHT11_Check()==0)
	{
		for(i=0;i<5;i++)
		{
			buf[i]=DHT11_Read_Byte();
		}
		if((buf[0]+buf[1]+buf[2]+buf[3])==buf[4])
		{
			*humidity=buf[0];
			*temperature=buf[2];
		}
	}
	else 
		return 1;
	return 0;	    
}