mySerial.begin(38400); //Serial communcation for Aircasting Application
You are not using an AirCasting module. The default data transmission mode baud rate for the HC 05 is 9600 baud. Have you have gone into AT mode and changed it? If not, set the software serial baud rate to 9600.
You really should be working with a standard BT terminal app on yuour phone instead of something you put together. I use the Serial Bluetooth Terminal app from Kai Morich https://play.google.com/store/apps/details?id=de.kai_morich.serial_bluetooth_terminal&hl=en_US
I need to make an app because the BT module is connected to a gas sensor. I'm making an air pollution-detecting device.