Starting project with Arduino, RFID, Ethernet.

Hi guys! I am new in Arduino and I want to start the project. I need your recommendations.

What do I need in my system?

I need door lock control system with Ethernet and RFID. System will work like following:

People have cards. Any guy put the card at the RFID element and Arduino connect to HTTP-server via Ethernet! HTTP-server find record with ID of this card... and get back respond with code "YES" or "NO". Arduino open the lock of door if code is "OK" and do nothing else!

So! Friends, tell me please, what hardware you recommend me to do all that I said above.

What I think. 1) The Arduino Duemilanove ("2009") (~ 45$) [or Russian analog «Cosmo Black Star» (33$)] 2) Arduino Ethernet Shield (~40$) [or other?] 3) RFID-reader ( ~??? ) Which do you recommend... and how much it cost? 4) Wires and plate to connect all wires (or can I connect all without plastic plate?)

I must to do this system, and I want to know what must I buy and how much it will cost.

This system will be on many doors ( about 100 doors) and cost play big role!

Thanks for help.

Demanding a reply probably won't help.

That said, if I was doing a 100-unit project, I'd probably consider the following...

  1. Design the doors to use a cheaper processor, if any, in the door. Most of the commercial systems I've seen don't have processors at the doors - just sensors (RFID, pushbutton) and actuators (strike-plates or magnetic closures). Do you have to use Ethernet, or would some sort of serial bus work?

  2. What are the consequences of the system failing? Do you have any legal, insurance, or regulatory things you have to comply with? Building codes, if a commercial building?

  3. How secure does it have to be?

  4. How will people get out in a fire? Will the system need to be tied into a fire system? How will fire fighters get into the rooms (your fire department may have rules about this)?

  5. I would probably print my own PCBs if I was doing 100x of something.

  6. How secure is the Ethernet network? How do I avoid someone doing ARP poisoning or something, particularly someone in Room X who shouldn't have access to Room Y? How do I keep them from taping into the control network? Etc.

  7. How will I power this in a power outage? Should the doors lock or unlock if the power system is lost? What about a power at the same time as a fire?

  8. Most commercial systems have ways of detecting a forced door. Do you need that?

  9. What causes door mechanisms to fail in your area? A professional installer would know this (for instance, some insects can render some systems completely insecure if those bugs are common)

I'm not trying to discourage you - but make sure you know what you are getting into.