基于STM8的DHT11溫濕度傳感器的驅(qū)動代碼設(shè)計

#include "typedef.h"

#include

#include "TemDHT11.h"

#ifndef _DHT11_TYPE

#define _DHT11_TYPE

//連接端口

#define DHT11_Dir P2DIR

#define DHT11_In P2IN

#define DHT11_Out P2OUT

#define DHT11_Bit BIT4

#endif

//8bit濕度+8bit濕度小數(shù)點

//8bit溫度+8bit溫度小數(shù)點

//數(shù)據(jù)位為0是高電平26~28us | 1高電平70us

u8 DHT11_Data[5] = {0}; //從DHT11中讀到的數(shù)據(jù)

void read_DHT11(u8 *Data)

{

u8 re,m,n,Time_out;

DHT11_Dir &= (~DHT11_Bit); //引腳為輸入

for(n = 0; n < 5; n++)

{

for(m = 0; m < 8; m++)

{

while( !(DHT11_In & DHT11_Bit) ); //每1bit以50us低電平時限開始，直到高電平到來

delay_us(30);

re = 0;

if((DHT11_In & DHT11_Bit)) //30us后還是高電平說明是1

{

re = 1;

}

Time_out = 2;

while((DHT11_In & DHT11_Bit) && (Time_out++ ));

if(Time_out == 1) //超時處理

{

break;

}

*Data <<= 1;

if(re)

{

*Data |= 0x01;

}

}

Data++;

}

}

//DHT11的握手協(xié)議模擬和數(shù)據(jù)的讀取

u8 DHT11_GetData(void)

{

u8 o,sum;

DHT11_Dir |= DHT11_Bit;

DHT11_Out &= ~DHT11_Bit; //拉低，發(fā)出開始信號

delay_ms(18); //拉低18ms

DHT11_Out |= DHT11_Bit; //拉高20us等待

delay_us(20);

DHT11_Dir &= (~DHT11_Bit);

if( !(DHT11_In & DHT11_Bit) ) //DHT11響應(yīng)

{

while( !(DHT11_In & DHT11_Bit) ); //80us低電平，等待DHT11的響應(yīng)信號

while( (DHT11_In & DHT11_Bit) ); //DHT11準備發(fā)送數(shù)據(jù)

read_DHT11(DHT11_Data); //主機接收數(shù)據(jù)

sum = 0;

for(o = 0; o < 4; o++) //數(shù)據(jù)校驗

{

sum += DHT11_Data[o];

}

if(sum != DHT11_Data[4])

{

return 0;

}

else

{

return 1;

}

}

return 0;

}

//對溫度濕度進行格式化(如果獲取溫度成功)

void DHT11_format(char *Des_str)

{

Des_str[0] = DHT11_Data[0]/10 + 0x30;

Des_str[1] = DHT11_Data[0] + 0x30;

Des_str[2] = '.';

Des_str[3] = DHT11_Data[1]/10 + 0x30;

Des_str[4] = DHT11_Data[1] + 0x30;

Des_str[5] = '%';

Des_str[6] = ' ';

Des_str[7] = DHT11_Data[2]/10 + 0x30;

Des_str[8] = DHT11_Data[2] + 0x30;

Des_str[9] = '.';

Des_str[10] = DHT11_Data[3]/10 + 0x30;

Des_str[11] = DHT11_Data[3] + 0x30;

Des_str[12] = 'C';

Des_str[13] = 0;

}