#include <LiquidCrystal.h>
 #include <SoftwareSerial.h>
 
LiquidCrystal lcd(7,6,5,4,3,2);
SoftwareSerial hc06(0,1); 
int redLed = 10;
int greenLed = 12;
int buzzer = 8;
int smokeA0 = A0;
int sensorThres = 300;

void setup() { 
  Serial.begin(9600);
  Serial.println("Enter AT commands:");
  hc06.begin(9600);
 
}
void loop() {
  if(hc06.available()){
    Serial.write(hc06.read()); 
  }

  if(Serial.available()){
    hc06.write(Serial.read()); 
  }






 pinMode(redLed, OUTPUT);
 pinMode(greenLed, OUTPUT);
 pinMode(smokeA0, INPUT);
 Serial.begin(9600);
 lcd.begin(16,2);
  }

  void loop() { 
  int analogSensor = analogRead(smokeA0);

 Serial.print("Pin A0 :");
 Serial.println(analogSensor);
 lcd.print("smoke Level:");
 lcd.print(analogSensor-50);

 if (analogSensor-50 > sensorThres)
  {
  digitalWrite(redLed, HIGH);
  lcd.setCursor(0, 2);
  lcd.print("Alert...!!!");
  digitalWrite(12, LOW);
  tone(buzzer, 1000, 200);
  }
  else
 {
  digitalWrite(redLed, LOW);
  digitalWrite(12, HIGH);  
  lcd.setCursor(0, 2);
  lcd.print("....Normal....");
  noTone(buzzer); 
  }
  delay(500); 
   lcd.clear();
}
가스센서를 이용한 lcd에 블루투스 모듈을 사용하는데 시리얼모니터가 제대로 동작이 안됩니다.