아두이노(arduino) - 온습도센서(DHT11)를 사용해보자

소스1 -연결만 잘하고 넣으면 시리얼 모니터에 온도와 습도가 나옵니다. 습도센서 모델명으로 검색하면 쉽게 찾으실 수 있어요 저도 주워온거-

#define dht11_pin 14 //Analog port 0 on Arduino Uno

//#define dht11_pin 54 //Analog port 0 on Arduino Mega2560

byte read_dht11_dat()

{

byte i = 0;

byte result=0;

for(i=0; i< 8; i++)

{

while (!digitalRead(dht11_pin));

delayMicroseconds(30);

if (digitalRead(dht11_pin) != 0 )

bitSet(result, 7-i);

while (digitalRead(dht11_pin));

}

return result;

}

void setup()

{

pinMode(dht11_pin, OUTPUT);

digitalWrite(dht11_pin, HIGH);

Serial.begin(9600);

Serial.println("Ready");

}

void loop() 

{

byte dht11_dat[5]; 

byte dht11_in;

byte i;// start condition

digitalWrite(dht11_pin, LOW);

delay(18);

digitalWrite(dht11_pin, HIGH);

delayMicroseconds(1);

pinMode(dht11_pin, INPUT);

delayMicroseconds(40); 

if (digitalRead(dht11_pin))

{

Serial.println("dht11 start condition 1 not met"); // wait for DHT response signal: LOW

delay(1000);

return;

}

delayMicroseconds(80);

if (!digitalRead(dht11_pin))

{

Serial.println("dht11 start condition 2 not met"); //wair for second response signal:HIGH

return;

}

delayMicroseconds(80);// now ready for data reception

for (i=0; i<5; i++)

{ dht11_dat[i] = read_dht11_dat();} //recieved 40 bits data. Details are described in datasheet

pinMode(dht11_pin, OUTPUT);

digitalWrite(dht11_pin, HIGH);

byte dht11_check_sum = dht11_dat[0]+dht11_dat[2];// check check_sum

if(dht11_dat[4]!= dht11_check_sum)

{

Serial.println("DHT11 checksum error");

}

Serial.print("Current humdity = ");

Serial.print(dht11_dat[0], DEC);

Serial.print("% ");

Serial.print("temperature = ");

Serial.print(dht11_dat[2], DEC);

Serial.println("C ");

delay(2000); //fresh time

}