模块简介

1. DHT11是用来检测空气温度和湿度的模块。
2. 测量范围：

• 湿度： 20% ~ 9 0%（精度5.0%）
• 温度：0 ~ +50 ℃（精度2℃）

1. 响应时间：<50ms
2. 低功耗、小体积、稳定可靠

接线

DHT11		Arduino
+	->	5V
OUT	->	A0
-	->	GND

加载库文件

到https://arduino-info.wikispaces.com/file/view/DHT-lib.zip/545470280/DHT-lib.zip下载MQ135的库文件，在Arduino IDE中，点击项目->加载库->添加一个.zip库，选择下载好的DHT-lib.zip文件即可。

示例程序

#include <dht.h>
dht DHT;
#define DHT11_PIN A0
void setup(){
  Serial.begin(115200); 
  Serial.println("DHT TEST PROGRAM "); 
  Serial.print("LIBRARY VERSION: ");     
  Serial.println(DHT_LIB_VERSION); 
  Serial.println(); 
  Serial.println("Type,\tstatus,\tHumidity (%),\tTemperature (C)");
}

void loop(){ 
  Serial.print("DHT11, \t"); 
  int chk = DHT.read11(DHT11_PIN); 
  switch (chk){ 
    case DHTLIB_OK: 
                  Serial.print("OK,\t"); 
                  break;
    case DHTLIB_ERROR_CHECKSUM: 
                  Serial.print("Checksum error,\t"); 
                  break;
    case DHTLIB_ERROR_TIMEOUT: 
                  Serial.print("Time out error,\t"); 
                  break; 
    case DHTLIB_ERROR_CONNECT: 
                  Serial.print("Connect error,\t"); 
                  break; 
    case DHTLIB_ERROR_ACK_L: 
                  Serial.print("Ack Low error,\t"); 
                  break;
    case DHTLIB_ERROR_ACK_H: 
                  Serial.print("Ack High error,\t"); 
                  break; 
    default:  Serial.print("Unknown error,\t"); 
                  break; 
    }
// DISPLAY DATA 
  Serial.print(DHT.humidity, 1); 
  Serial.print(",\t"); 
  Serial.println(DHT.temperature, 1); 
  delay(2000);
}

输出结果

DHT TEST PROGRAM
LIBRARY VERSION: 0.1.20

Type,    status,    Humidity (%),    Temperature (C)
DHT11,     OK,    32.0,    29.0
DHT11,     OK,    33.0,    28.0
DHT11,     OK,    33.0,    28.0
DHT11,     OK,    33.0,    28.0  (BREATHE On Sensor ! )
DHT11,     OK,    75.0,    30.0
DHT11,     OK,    75.0,    29.0
DHT11,     OK,    75.0,    29.0

参考文献

1. https://arduino-info.wikispaces.com/DHT11-Humidity-TempSensor
2. https://brainy-bits.com/tutorials/dht11-tutorial/