To control the door lock with the android app, the password which is checked by the Arduino programming through Bluetooth connection and if it is right, then the motor will unlock the door with the help of motor driver circuit.
To automatize the home appliances by controlling the switching process (on/off) with the help of Bluetooth connection through android app based on Arduino programming.
To convert the 12V DC to 230V AC based on full wave rectifier circuit having transformers, diodes and capacitors.