RFID - The Mysterious Wiegand Interface Protocol

[bigdogguru]

Please post your recommendations on projects, docs, tips and tricks concerning the Wiegand Interface Protocol used in RFID Technologies.

Many beginners in RFID, purchase a RFID reader hoping to quickly connect it to their trusty old RS-232 connection on the back of their PC, only to find out the reader uses a Wiegand Interface. "What's a Wiegand Interface and Protocol?" You Ask.

Hence the topic of this thread:

Wiegand Interface Wiki

 

[bigdogguru]

Wiegand guidelines as proscribed by the SIA’s Access Control Standard Protocol for the 26-Bit Wiegand Reader Interface

Wiegand Protocol Format

 

[bigdogguru]

An excellent project using Wiegand protocol to send the data from RFID reader to a PIC, good example of implementing the Wiegand Interface:

RFID Door Lock with Wiegand Protocol

Project Schematic

Project Source Code

 

[bigdogguru]

The term Wiegand is applied to several characteristics related to access control readers and cards. Unfortunately, the word is used carelessly and can lead to unnecessary confusion.

Here are the basics.
Wiegand is:
1. A specific reader-to-card interface
2. A specific binary reader-to-controller interface
3. An electronic signal carrying data
4. The standard 26-bit binary card data format
5. An electromagnetic effect
6. A card technology

For the purposes of this white paper, we will address items 2 and 4.

 

[bigdogguru]

Here is an Arduino based project using RFID and Wiegand Interface Protocol with source code:



**broken link removed**

 

[bigdogguru]

When creating a RFID interface with Arduino, there are a few commercial RFID readers available on the market. Most of these readers talk UART which is easy to interface but the cost of the device can be quite high. Cheap RFID readers are readily available on eBay. These readers talk Wiegand26 as a industry standard protocol. Currently, there are no Arduino libraries that can talk Wiegand26 so I have created this project to ease interfacing of Wiegand protocol devices.



Arduino Wiegand Interface

 

[bigdogguru]

Interesting thread discussing interfacing the Wiegand Protocol:


**broken link removed**

 

[bigdogguru]

I have purchased many commercial RFID readers over the last few years (mostly from ebay) and virtually all of them utilize the Wiegand interface to output the card data read. Unless you have a card access controller panel the only other way to look at the data output is to use an oscilloscope or logic analyzer. Decoding and formatting all of those bits is very time consuming and boring to say the least. I decided to build a wiegand converter unit that would receive, format and display all of the data that was output. I also wanted it to be portable so I designed it to run off of a 9-volt battery that would be used to power both the converter and the commercial reader.


ProxClone - Wiegand Converter

 

[bigdogguru]

The unit is self contained and does not require the use of a PC or other external equipment to operate. Operation is simple and straightforward. Simply hold a card near the antenna and the unit reads and decodes the information from the card. The information is then formatted and displayed on a 4x20 character LCD. If the operator wishes to make a copy of the card he simply brings a T5557/5567 Read/Write card near the antenna and presses the "write" button. The LED flashes and in less than a second the R/W card has been programmed with the information that was read from the original. Voila !! - A clone card.



ProxClone - Proximity Card Reader/Cloner

 

[bigdogguru]

Adding and testing Wiegand interface and protocol


Adding and testing Wiegand interface and protocol

 

[bigdogguru]

A very detailed report concerning various aspects of the Wiegand Protocol:

The word \Wiegand" stands for one of many things:

John R. Wiegand is a scientist who, in 1975, discovered the Wiegand eect which is a nonlinear magnetic phenomenon, used in specially produced

Wiegand wire, the application of which in access control gave rise to the

Wiegand format, which {used on keycards{ indirectly denes the

Wiegand interface and Wiegand protocol that are used between door reader and security panel.

Analyzing a Modern Cryptographic RFID System

 

[bigdogguru]

The Wiegand interface is a de-facto serial data and wiring standard commonly used in many security applications to connect sensors to control systems. However many variations exist so that a “standard” Wiegand interface cannot be assumed in all cases.
For a Wiegand interface to operate correctly, the electrical format, timing parameters and data format/sequence must ALL be correct.


**broken link removed**

 

[bigdogguru]

Wiegand to Serial Driver - CCS Code Example:


Wiegand to Serial Driver