温湿度传感器
DHT11_DA
使用方法
/* USER CODE BEGIN 1 */ uint8_t DHT11_BUF[2] = { 0 };//用于存放DHT11数据 /* USER CODE END 1 */ /* USER CODE BEGIN 2 */ HAL_Delay(500) DHT11_Init()//传感器芯片的初始化 HAL_Delay(1500) DHT11_ReadData(DHT11_BUF);//读出DHT11传感器数据(参数是存储数据的数组指针) /* USER CODE END 2 */
while (1) { DHT11_ReadData(DHT11_BUF); //读出DHT11传感器数据（参数是存放数据的数组指针） printf("湿度：d％ 温度：d℃\r\n", DHT11_BUF[0], DHT11_BUF[1]); //显示日期时间 HAL_Delay(1500); //毫秒延迟 dht11.c
#include "dht11.h" #include "main.h" void DHT11_IO_OUT (void){ ///端口变成输出 GPIO_InitTypeDef GPIO_InitStruct = {0}; GPIO_InitStruct.Pin = DHT11_DA_Pin; GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; GPIO_InitStruct.Pull = GPIO_NOPULL; GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH; HAL_GPIO_Init(GPIOB, &GPIO_InitStruct); } void DHT11_IO_IN (void){ ///端口变成输入 GPIO_InitTypeDef GPIO_InitStruct = {0}; GPIO_InitStruct.Pin = DHT11_DA_Pin; GPIO_InitStruct.Mode = GPIO_MODE_INPUT; GPIO_InitStruct.Pull = GPIO_PULLUP; HAL_GPIO_Init(GPIOB, &GPIO_InitStruct); } void DHT11_RST (void){ //DHT11端口复位，发出起始信号（IO发送） DHT11_IO_OUT(); HAL_GPIO_WritePin(GPIOB,DHT11_DA_Pin, GPIO_PIN_RESET); HAL_Delay(20); //拉低至少18ms HAL_GPIO_WritePin(GPIOB,DHT11_DA_Pin, GPIO_PIN_SET); delay_us(30); ///主机拉高20~40us } uint8_t Dht11_Check(void){ //等待DHT回应11:未检测到返回1:DHT11，返回0:成功（IO接收） uint8_t retry=0; DHT11_IO_IN();//IO到输入状态 while (HAL_GPIO_ReadPin(GPIOB,DHT11_DA_Pin)&&retry<100){//DHT11会拉低40~80us retry ; delay_us(1); } if(retry>=100)return 1; else retry=0; while (!HAL_GPIO_ReadPin(GPIOB,DHT11_DA_Pin)&&retry<100){//DHT11拉低后，将再次拉40~80us retry ; delay_us(1); } if(retry>=100)return 1; return 0; } uint8_t Dht11_ReadBit(void){ //从DHT11读取一个位 返回值：1/0 uint8_t retry=0; while(HAL_GPIO_ReadPin(GPIOB,DHT11_DA_Pin)&&retry<100 retry ; delay_us(1); } retry=0; while(!HAL_GPIO_ReadPin(GPIOB,DHT11_DA_Pin)&&retry<100 retry ; delay_us(1); } delay_us(40)us //用于判断高低电平，即数据1或0 if(HAL_GPIO_ReadPin(GPIOB,DHT11_DA_Pin))return 1; else return 0; } uint8_t Dht11_ReadByte(void){ //从DHT读一个字节 返回值：读取的数据 uint8_t i,dat; dat=0; for (i=0;i<8;i ){ dat<<=1; dat|=Dht11_ReadBit(); } return dat; } uint8_t DHT11_Init (void){ //DHT11初始化 DHT11_RST();//DHT11端口复位，发出起始信号 return Dht11_Check(); //等待DHT11回应 } uint8_t DHT11_ReadData(uint8_t *h){ ///读取数据//湿度值(十进制，范围:20%~90%) ，温度值(十进制，范围:0~50°)，返回值：0，正常；1，失败 uint8_t buf[5]; uint8_t i; DHT11_RST();//DHT11端口复位，发出起始信号 if(Dht11_Check()==0){ //等待DHT11回应 for(i=0;i<5;i ){//读取5位数据 buf[i]=Dht11_ReadByte(); //读出数据 } if((buf[0] buf[1] buf[2] buf[3])==buf[4]){ ///数据校验 *h=buf[0]; ///将湿度值放入指针1 h ; *h=buf[2]; ///将温度值放入指针2 } }else return 1; return 0; } dht11.h
#ifndef DHT11_DHT11_H_ #define DHT11_DHT11_H_ #include "stm32f1xx_hal.h" #include "../delay/delay.h" void DHT11_IO_OUT (void); void DHT11_IO_IN (void); void DHT11_RST (void); uint8_t Dht11_Check(void); uint8_t Dht11_ReadBit(void); uint8_t Dht11_ReadByte(void); uint8_t DHT11_Init (void); uint8_t DHT11_ReadData(uint8_t *h); #endif /* DHT11_DHT11_H_ */