Present As Ion (beta)

PC BASED CONTROLLER FOR HOME AUTOMATION

MOHD HANAFIAH BIN NAWI B010510031 4 BEKC

SUPERVISOR : EN AHMAD AIZAN BIN ZULKEFLI

Objectives:

To apply PC based controller to the electrical appliances at home.

To maximize using the PC in our home.

Problems: Waste of energy and time to turn ON and OFF the electrical devices at far place.

Difficult to old man/women and disabled people to turn ON and OFF the electrical appliances.

Abstract Modern homes with an emphasis on comfort and convenience are being increasingly equipped with programmable installation technology that has already become a matter of course in functional buildings. Different technologies are available to control different things through PC. And there various technologies that are useable depending what devices needs to be controlled and how long away they are from PC. One simple way to do controlling is connect several relays to PC parallel port, and then make their contacts to switch power to different devices on and off. This can be used to control anything (on or off) what you can wire to PC and back to appliance. With suitable software on the PC you could use the PC for controlling whatever that is wired to those relays on electrical panel. For this project, I will use Visual Basic 6.0.

•Using a Visual Basic program, you drive a signal high on the parallel port. (You can use the serial port if you want, but the parallel port has more data/ground signals on it just in case you want to expand this project into something bigger) •The signal talks to a *very* simple circuit. •The circuit activates a relay. •The relay is connected to an extension cord. •You plugin whatever you want to the extension cord for power. •The light/appliance/device goes on (or off) based on whatever you send to the parallel port.

Relays •We want to use a DC-signal from the computer to switch on or off an AC-based extension cord, and anything plugged into it. •This is what Relays do. Relays are mechanical - they having a moving part inside (called an armature). •Relays operate on the same principle as a motor: they have an electro-magnet inside that energizes. Instead of repelling against another magnet like a motor does to produce rotation, instead they move in two directions to complete a DC-circuit •I recommend using a SPDT, 9-volt coil Relay. I also recommend making sure that the relay can handle 5 or 10 amps of current. Although a single device or appliance may not need that much current, you may want to plug other things into this project at the same time.

Parallel Port

The parallel port has 8-data pins and 8-ground pins.(Refer to the diagram below) The rest of the pins are not important for our purposes. The data pins are pins 2 through 9 and the ground pins are 18 through 25. The data pins source 5 volts of ~2 milliamp of DC current. There is not enough current to activate the coil on the Relay described before. So, we use a second power adapter to do it (or a battery).

The Circuit 1. 2. 3. 4. 5.

Visual Basic program turns on parallel port data pin. Data pin triggers a transistor. Transistor triggers a Relay. Relay turns on power to the extension cord. Anything attached to the extension cord comes alive (or goes off).

Start

M E T H O D O L O G Y

Literature Review Project Proposal Software Design Software Test

Fail

Pass Hardware Design Fail Hardware Test Pass Integration between software and hardware

Troubleshooting and testing Pass

Full report End

Fail

(+)Vcc3

Pin 2

Pin 18

Extension Cord

(-) Ground 3 Battery (+)Vcc1

(+)Vcc2

NO (-) Ground 1 External Devices

Common NC

C (-) Ground 2

B

NPN Transistor C

The expected outcome of the project

At the end of this project, PC Based Controller For Home Automation will be designed as required.