 GPRS gprs(7, 8, 9600,"cmnet");
 char buffer[128];
 //Debug in PC
-bool is_debug = true;
+#define is_debug true
 
 void setup(){
 
     Serial.begin(9600);
-    //DSM init
+
+    //initialize DSM501A
     pinMode(3,INPUT);
     starttime = millis();
+
+    //initialize I2C LCD-1602
+    lcd.init();
+    lcd.backlight();
+    //initialize gprs
     if(!is_debug){
         gprs.init();
         // attempt DHCP

        //gprs.close();
        //gprs.disconnect();
    }else{
        Serial.print((float)DHT11.temperature, 2);
        Serial.print(",");
        Serial.println((float)DHT11.humidity, 2);
    }
    
    }

    {
        ratio = lowpulseoccupancy/(sampletime_ms*10.0);  // Integer percentage 0=>100
        concentration = 1.1*pow(ratio,3)-3.8*pow(ratio,2)+520*ratio+0.62; // using spec sheet curve
        lowpulseoccupancy = 0;
        starttime = millis();
     
