Access control with Arduino Mega & Wiegand RFID Card Reader

The needed was replace the old key access connected to my automatic access gate , during the investigation on internet the decision was to upgrade  all the access of  my house with RFID access control .
I'm a maker so I don't like by a system and install, I wand do it as i like.
First of all need to do some shopping ... ebay is my preferred market place and for electronic ICs_Processors_Store is the best, so put all the necessary  in your basket : 

N. 3 Waterproof Security Door Black ID Wiegand 26 RFID Card Reader 125KHz EM4100




N .1 Mega 2560 ATmega2560-16AU Board Arduino-compatible ( Arduino team sorry this is not the original one .. :-( ....) 





N.5pcs RFID Tokens 125Khz EM4100



This is the minimum required  for start .. sure you need a laboratory with a minimum set of  component and knowledge of Arduino programming a Electronics.

I have start my project using Arduino library developed from Monkey Board
( http://www.monkeyboard.org )

You can download the original library from : https://github.com/monkeyboard/Wiegand-Protocol-Library-for-Arduino.git

Unfortunately this library is able to manage only one reader and so only one access can be managed, the library is built on the hardware capability of the Arduino UNO , only two interrupt available on pin,  both used for the two line communication used from Wiegand protocol.

Thanks  Arduino Mega more interrupt available  on external pin if you use due the limit is the number of pin ..
From Arduino web site http://arduino.cc/en/Reference/attachInterrupt is possible compare the interrupt capability for each boards :

Board	int.0	int.1	int.2	int.3	int.4	int.5
Uno, Ethernet	2	3
Mega2560	2	3	21	20	19	18
Leonardo	3	2	0	1	7
Due	(see below)

The Arduino Due board has powerful interrupt capabilities that allows you to attach an interrupt function on all available pins. You can directly specify the pin number in attachInterrupt().

With six external interrupt on pin change  Arduino Mega can manage three RFID readers and consequently three doors/gate, but the library need some modification for manage all the interrupt and for recognize from which readers come the request.

In the modified library the command WIENGAND.getGateActive(); was added in the WIENGND class for recognize the gate from where the request come .

Library can be download from : https://github.com/ugge75/Wiegand-Protocol-Library-for-Arduino-MEGA-2560

I will update the blog  with the first release of software in the coming weeks.

Cheers..

Francesco