//dht11.c文件
#include "dht11.h"
GPIO_InitTypeDef GPIO_InitStruct;
u8 buff;
void Dht11_Init(void)
{
//1.初始化時鐘
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOG, ENABLE);
//2.初始化硬件
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_9;//PG9
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;//輸出模式
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;//推挽輸出
GPIO_InitStruct.GPIO_Speed = GPIO_Fast_Speed;//速度 快速 25MHz
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;//上拉
GPIO_Init(GPIOG,&GPIO_InitStruct); 
}
/***************傳入?yún)��?shù)確定是輸出還是輸入**********************/
void pin_mode(GPIOMode_TypeDef mode)
{
GPIO_InitStruct.GPIO_Mode = mode;//模式切換
GPIO_Init(GPIOG,&GPIO_InitStruct);//加進(jìn)結(jié)構(gòu)體
}
/******************初步配置（開始信號）**************************/
uint8_t start_dht11(void)
{
//1.設(shè)置為輸出模式,并且空閑狀態(tài)為高電平
pin_mode(GPIO_Mode_OUT);
PGout(9)=1;
delay_us(2);
//2.主機(jī)拉低 至少18ms
PGout(9)=0;
delay_ms(20);
//3.主機(jī)拉高 20-40us
PGout(9)=1;
delay_us(30);
//4.設(shè)置為輸入模式，進(jìn)入兩個電平跳變
pin_mode(GPIO_Mode_IN);
if(!PGin(9))//if(PGin(9)==0)
{
//檢測低到高跳變
while(!PGin(9));
//檢測高到底跳變
while(PGin(9));
return 1;
}
return 0;
}
/*********************獲取8bit數(shù)據(jù)*******************/
void get_8bit_data(void)
{
u8 i=0;
for(i=0;i<8;i++)
{
buff = buff <<1;
while(!PGin(9));//過濾低電平時間，確定高電平到來
delay_us(30);
if(PGin(9))//如果還是高電平，數(shù)據(jù)就是1
{
buff |= 0x01;
}
else//低電平的話，數(shù)據(jù)就是0
{
buff &= 0xfe;
}
while(PGin(9));//過濾剩余的高電平時間
}
}
/****************獲取溫濕度數(shù)據(jù)*******************/
uint8_t get_dht11_data(char DataBuf[])
{
if(start_dht11())
{
get_8bit_data();//獲取的是濕度整數(shù)
DataBuf[0] = buff;
get_8bit_data();//獲取的是濕度小數(shù)
DataBuf[1] = buff;
get_8bit_data();//獲取的是溫度整數(shù)
DataBuf[2] = buff;
get_8bit_data();//獲取的是溫度小數(shù)
DataBuf[3] = buff;
get_8bit_data();//獲取的是校驗和
DataBuf[4] = buff; 
}
if(DataBuf[4] == DataBuf[0]+DataBuf[1]+DataBuf[2]+DataBuf[3])
{
return 1;
}
else
return -1;
}

//mian.c文件
#include "stm32f4xx.h"
#include "led.h"
#include "key.h"
#include "exti.h"
#include "sys.h"
#include "tim.h"
#include "pwm.h"
#include "uart.h"
#include "stdio.h"
#include "dht11.h"
uint16_t uart1_recv_data;
//重定向fputc 換個方向，此路不通，屏幕輸出不了就往串口發(fā)
//fputc fputs / fgetc fgets
int fputc(int ch,FILE *f)
{
USART_SendData(USART1,ch);
while(USART_GetFlagStatus(USART1,USART_FLAG_TXE) == RESET);
return ch;
}
//串口接收中斷
void USART1_IRQHandler(void)
{
//判斷確實進(jìn)中斷標(biāo)志
//if(USART_GetITStatus(USART1, USART_IT_RXNE) !=RESET)//==SET
if(((USART1->SR) & (0x1<<5)) !=0)//發(fā)生中斷 該為由硬件自定置1
{
//清楚中斷標(biāo)志位 往里面寫1 記住一定要清空
//USART_ClearITPendingBit(USART1,USART_IT_RXNE);//用寄存器方式自己去改
USART1->SR &= ~(0x1<<5);
uart1_recv_data = USART_ReceiveData(USART1);
} 
}
int main(void)
{
u8 ret;
char DataBuf[5] = {0};
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//NVIC 分組
SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK_Div8);//滴答定時器8分頻
LED_Init();
Key_Init();
//Exti_Init();
//Tim_Init();
//Pwm_Tim14();
Uart_Init(115200);
Dht11_Init();
printf("hello uart1\r\n");
while(1)
{
ret = get_dht11_data(DataBuf);
if(ret == 1)
{
printf("溫度:%d ℃ 濕度:%d\r\n",DataBuf[2],DataBuf[0]); 
}
else
{
printf("get dht11 failed!");
}
delay_s(2);
}
return 0;
}