温湿度传感器-DHT11

来源：互联网发布：5sa1528支持什么网络编辑：程序博客网时间：2024/04/28 02:09
/****************************************************文件名：温湿度传感器测试实验MCU : Arduino Mega2560器件：ArduinoMega2560核心板, DHT11传感器, 导线若干******************************************************/int DHpin = 40;byte dat[5];byte read_data(){byte data;for(int i=0; i<8; i++) {if(digitalRead(DHpin) == LOW) {   while(digitalRead(DHpin) == LOW); //等待50us；delayMicroseconds(30); //判断高电平的持续时间，以判定数据是‘0’还是‘1’；if(digitalRead(DHpin) == HIGH)   data |= (1<<(7-i)); //高位在前，低位在后；   while(digitalRead(DHpin) == HIGH); //数据‘1’，等待下一位的接收；   }}return data;}void th_test(){digitalWrite(DHpin,LOW); //拉低总线，发开始信号； delay(30); //延时要大于18ms，以便DHT11 能检测到开始信号；digitalWrite(DHpin,HIGH);delayMicroseconds(40); //等待DHT11 响应；pinMode(DHpin,INPUT);while(digitalRead(DHpin) == HIGH);delayMicroseconds(80); //DHT11 发出响应，拉低总线80us；if(digitalRead(DHpin) == LOW);delayMicroseconds(80); //DHT11 拉高总线80us 后开始发送数据； for(int i=0;i<4;i++) //接收温湿度数据，校验位不考虑；dat[i] = read_data();pinMode(DHpin,OUTPUT);digitalWrite(DHpin,HIGH);//发送完一次数据后释放总线，等待主机的下一次开始信号；}void setup(){Serial.begin(9600);pinMode(DHpin,OUTPUT);}void loop(){th_test();Serial.print("Current humdity = ");Serial.print(dat[0], DEC); //显示湿度的整数位；Serial.print('.');Serial.print(dat[1],DEC); //显示湿度的小数位；Serial.println('%');Serial.print("Current temperature = ");Serial.print(dat[2], DEC); //显示温度的整数位；Serial.print('.');Serial.print(dat[3],DEC); //显示温度的小数位；Serial.println('C');delay(700);}
0 0