#include <Arduino.h>

String str;
float ratio;
float RS_gas;
float sensor_volt;
int blueToothVal;
int sensorValue;

void setup() {
  Serial.begin(9600);
  pinMode(A0, INPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  digitalWrite(6, 1);// OFF
  digitalWrite(7, 1);// OFF
}

void loop() {
  bluetooth();
  sendGas();
}

void bluetooth()
{
  while (Serial.available())
  {
    {
      str = Serial.readStringUntil('\n');
      //Serial.print(str);
    }

    blueToothVal = (str.toInt());

    switch (blueToothVal)
    {
      case 1:
        //ON
        digitalWrite(6, 0); // ON 220V Light
        delay(10);
        break;

      case 2:
        //OFF
        digitalWrite(6, 1); // OFF 220V Light
        delay(10);
        break;

      case 3:
        //ON
        digitalWrite(7, 0); // ON 220V Socket
        delay(10);
        break;

      case 4:
        //OFF
        digitalWrite(7, 1); // OFF 220V Socket
        delay(10);
        break;

    }//end of SWITCH

  }//end of Serial

}//end of function

void sendGas() {
  sensorValue = analogRead(A0);
  sensor_volt = (float)sensorValue / 1024 * 5.0;
  RS_gas = (5.0 - sensor_volt) / sensor_volt;
  ratio = RS_gas / (0.6);
  Serial.println(ratio);
  delay(1000);
}