dht12.rar_DHT11_DHT12_MDK_dht12湿度总是95_dht12程序

#include "DHT12.h" extern uint8_t Temperature,Humidity; void delay_ms(uint16_t ms) //粗略毫秒延时 { while(ms--) { delay_us(1000); } } void delay_us(uint16_t us) //粗略微秒延时 { uint16_t i=0,j=0; for(i=0;i<us;i++) for(j=0;j<6;j++); } //复位DHT12 void DHT12_Rst(void) { DHT12_IO_OUT(); //SET OUTPUT DHT12_DQ_RESET; //拉低DQ delay_ms(20); //拉低至少18ms DHT12_DQ_SET; //DQ=1 delay_us(30); //主机拉高20~40us } //等待DHT12的回应 //返回1:未检测到DHT12的存在 //返回0:存在 uint8_t DHT12_Check(void) { uint8_t retry=0,Data = 0; DHT12_IO_IN();//SET INPUT Data = DHT12_DQ_IN; while (Data&&retry<100) //DHT11会拉低40~80us { retry++; delay_us(1); Data = DHT12_DQ_IN; } if(retry>=100)return 1; else retry=0; Data = DHT12_DQ_IN; while (!Data&&retry<100)//DHT11拉低后会再次拉高40~80us { retry++; delay_us(1); Data = DHT12_DQ_IN; } if(retry>=100)return 1; return 0; } //从DHT12读取一个位 //返回值：1/0 uint8_t DHT12_Read_Bit(void) //低50us,高70us为1;低50us,高26~28us为0 { uint8_t retry=0,Data = 0; Data = DHT12_DQ_IN; while(Data&&retry<100)//等待变为低电平 50us { retry++; delay_us(1); Data = DHT12_DQ_IN; } retry = 0; Data = DHT12_DQ_IN; while(!Data&&retry<100)//等待变高电平 { retry++; delay_us(1); Data = DHT12_DQ_IN; } retry = 0; delay_us(40);//等待40us Data = DHT12_DQ_IN; if(Data)return 1; else return 0; } //从DHT12读取一个字节 //返回值：读到的数据 uint8_t DHT12_Read_Byte(void) { uint8_t i = 0,dat = 0; for (i=0;i<8;i++) { dat<<=1; dat|=DHT12_Read_Bit(); } return dat; } //从DHT12读取一次数据 //temp_integer:温度值(范围:0~50°) //temp_decimal:温度小数值 //humi_integer:湿度值(范围:20%~90%) //humi_decimal:湿度小数值 //返回值：0,正常;1,读取失败 uint8_t DHT12_Read_Data(uint8_t *humi_integer,/*uint8_t *humi_decimal,*/uint8_t *temp_integer/*,uint8_t *temp_decimal*/) { uint8_t buf[5] = {0}; uint8_t i = 0; DHT12_Rst(); if(DHT12_Check()==0) { for(i=0;i<5;i++)//读取40位数据 { buf[i]=DHT12_Read_Byte(); } if((buf[0]+buf[1]+buf[2]+buf[3])==buf[4]) { *humi_integer = buf[0]; //*humi_decimal = buf[1]; *temp_integer = buf[2]; //*temp_decimal = buf[3]; } }else return 1; return 0; } //初始化DHT12的IO口 DQ 同时检测DHT12的存在 //返回1:不存在 //返回0:存在 uint8_t DHT12_Init(void) { GPIO_InitTypeDef GPIO_InitStruct; RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); GPIO_InitStruct.GPIO_Pin = IO_PIN; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;//普通输出模式 GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;//推挽输出 GPIO_InitStruct.GPIO_Speed =GPIO_Speed_Level_3; GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;//上拉 GPIO_Init(IO_PORT, &GPIO_InitStruct); GPIO_ResetBits(IO_PORT,IO_PIN); DHT12_Rst(); return DHT12_Check(); } void dhtprin(void) { uint8_t Temperature_p,Humidity_p; if(!DHT12_Read_Data(&Humidity_p,&Temperature_p)) if(Humidity != Humidity_p||Temperature != Temperature_p) { Humidity = Humidity_p; Temperature = Temperature_p; OLED_ShowNum(100,4,Temperature,2,16); OLED_ShowNum(100,6,Humidity,2,16); Prin_json(); } }