Commented the Arduino code

Author: Devansh-Maurya

bluetooth/bluetooth.ino

@@ -1,75 +1,89 @@
 #include<SoftwareSerial.h>
-#define PIN A5
+
+//We're using pin 10 and 11 in RX and TX mode
 SoftwareSerial BT(10,11);
+//String that will store the command from mobile device
 String readdata;
-char data = 0;            //Variable for storing received data
+char data = 0;
 bool ledOn = false;
-int startDelay, stopAfter;
+//Variables used for implementing delay mechanism
+int startDelay, stopAfter;	
+//Used for reading data as it is received from the Bluetooth input stream
 char c;
-int bulb_1 = 0, bulb_2 = 0;
+//The two vaiables represent the two output pins to which bulbs are connected
+int bulb_1 = 0, bulb_2 = 0;	
 
 void setup()
 {
     BT.begin(38400);
-    Serial.begin(9600);   //Sets the baud for serial data transmission                               
-    pinMode(3, OUTPUT);  //Sets digital pin 13 as output pin
-    pinMode(2, OUTPUT);
+    Serial.begin(9600);   	//Sets the baud for serial data transmission
+    pinMode(3, OUTPUT);  	//Sets digital pin 3 as output pin
+    pinMode(2, OUTPUT);		//Sets digital pin 2 as output pin
 }
 
 void loop()
 {
-   while(BT.available())      // Send data only when you receive data:
+   while(BT.available())      	//Receive data as long as it is available
    {
     delay(10);
       data = BT.read();
       readdata+=data;
    }
 
-   //Read the incoming data & store into data
+   //Read the incoming data & store into readdata
    if(readdata.length()>0)
    {
-      Serial.print(readdata);          //Print Value inside data in Serial monitor
-      Serial.print("\n");   
+      Serial.print(readdata);          //Print value inside data in Serial monitor
+      Serial.print("\n");
 
       if(readdata == "1") {
+      	//If bulb 1 is selected, set bulb_1 to pin 3
         bulb_1 = 3;
+        //Keep the bulb off initially
         digitalWrite(bulb_1, LOW);
+        //Make readdata string empty
         readdata = "";
       }
 
       else if(readdata == "2") {
+      	//If bulb 2 is selected, set bulb_2 to pin 2
         bulb_2 = 2;
+        //Keep the bulb off initially
         digitalWrite(bulb_2, LOW);
         readdata = "";
       }
 
       else if(readdata == "01") {
+      	//If bulb 1 has been unchecked, make bulb_1 as 0 to disselect it
         bulb_1 = 0;
-        digitalWrite(bulb_1, LOW);
         readdata = "";
       }
 
       else if(readdata == "02") {
+      	//If bulb 1 has been unchecked, make bulb_1 as 0 to disselect it
         bulb_2 = 0;
-        digitalWrite(bulb_2, LOW);
         readdata = "";
       }
 
       if(readdata == "STOP") {
+      	//This signal is sent by pressing disconnect button on the app
+      	//It makes both the bulbs non-funtional
         bulb_1 = 0;
         bulb_2 = 0;
         readdata = "";
-        digitalWrite(bulb_1, LOW);
-        digitalWrite(bulb_2, LOW);
       }
 
       if(readdata == "ON") {        
+      	//This signal is sent by tapping the bulb when it is off
+      	//Used to switch on the selected bulb(s)
          digitalWrite(bulb_2, HIGH);
          digitalWrite(bulb_1, HIGH);
          readdata = "";
          ledOn = true;
       }
       else if(readdata == "OFF") {
+      	//This signal is sent by tapping the bulb when it is on
+      	//Used to switch off the selected bulb(s)
          digitalWrite(bulb_2, LOW);
          digitalWrite(bulb_1, LOW);
          readdata = "";
@@ -79,14 +93,14 @@ void loop()
         //Get index of 'e', number following 'e' indicates the number of seconds for which the bulb(s) should remain on
         c = readdata.indexOf('e');    
 
+        //Get the start delay and convert it to int
         startDelay = readdata.substring(1, c-1).toInt();
+        //Get the stop delay and convert it to int
         stopAfter = readdata.substring(c+1, readdata.length()-1).toInt();
 
-        if(startDelay != 0) {
-          delay(startDelay*10);
-          digitalWrite(bulb_1, HIGH);
-          digitalWrite(bulb_2, HIGH);
-        }
+	delay(startDelay*10);
+	digitalWrite(bulb_1, HIGH);
+	digitalWrite(bulb_2, HIGH);
 
         if(stopAfter != 0) {
           delay(stopAfter*10);