PBX Final Project in partial fulfillment of the requirement for the degree of Bachelor of Engineering in Computer Engineering, Hardware subgroup, Engineering Faculty, University of Isfahan, by Behdad Hosseini, 2002-2003.

 "Design and Implementing a 1-to-4 PBX System Using a Microcontroller", refer to "abstract.txt" for more technical information about the project. I presented my project at May 20, 2003 and got 19.75 from 20.

 These are all of my works including hardware schematics, software programs, thesis, PowerPoint presentation of a project under the title of "Design and implementing a 1-to-4 PBX system using a microcontroller" as the final project of the BS degree in computer engineering career (browse index.html for more information). I was graduated (I mean I hope ;-)) at the University of Isfahan, Isfahan. That wasn't a technical university but accepts students in a few fields like CE and EE...

 I would appreciate assistance of my friends and especially my family in completing the project: First my father, because of his wonderful help and knowledge as I never blocked by even big problems. Second my mother; She makes home a comfortable place for live and research and every possible creative activity that can be imagined, my sister for her help in montage of some board with a lot of patience, my classmates in Isfahan especially the ones in room #105 of the Mofateh resident hall for their support: Meysam MirAlipour, Abbas Nikabadi, Amin Rezaei and especially Mojtaba Jafari for his assistance in editing my thesis by Ms Word 2000, also Mohammad Abareghi for letting me use of his Computer while I were in Isfahan (that was a major favor), and my good friends, Hossein Yarahmadi and Zahra Haghshenas, for their support in all situations, and at last but not least, Mahmoud Arab and Rouhollah Bigdeli -one of the smartest guys I've ever met- for providing me the necessary documents and books as the references of my thesis. I also like to acknowledge everybody that I've forgotten to list above. 

 I started the project in the summer 2002 but couldn't complete it before the new term (I mean my new term at University of Tehran, MS degree). So I forced to temporary leave the work. I start working on it about beginning of the February 2003, and it lasts about 3 months. I hope I've done something useful especially for myself.

 I always say I've got many benefits from this project. I can classify them as the following:
 - Working with a microcontroller (MCS51), both hardware considerations and software programming.
 - Completing my experience and skills of editing using Microsoft Word.
 - Work with OrCad Capture that is a very useful utility for design and simulating electric and electronic circuits. I got familiar with plotting schematics using that CAD.

 And about my project, it is a private branch exchange (PBX) capable of handling 4 lines (means 4 phones for switch) and 1 trunk (means an external line usually from nearest Switching System in the city). It switches between them. Unfortunately my thesis is in Farsi (Persian) language but I attempted to make a good PowerPoint slides for the presentation of my work. I've used an AT89C52 microcontroller for the central controlling part of the project.

 And at last I will note my classified work (and documents):
 - An 8052-assembly program.
 - Hardware schematics using OrCad Capture.
 - Thesis using Microsoft Word 2000.
 - Presentation slides using Microsoft PowerPoint 2000.
 - WebPages using Microsoft FrontPage 2000.

 And there is something that really bothers me. That's I didn't use even a little piece of wire from labs of University of Isfahan; not because of I didn't want but because of they didn't want (at least that's my thought). Anyway I didn't use and I'm really happy of that (but thinking of their behavior still bothers me). I got 14 breadboards (!) form Sharif University of Technology (www.sharif.edu) and other requirements from my father. It's appropriate to thank the staff at Sharif University of Technology for their support and trust.

Behdad Hosseini, 8 April 2003, Tehran.
behdad@laposte.net