Comparing the Two RFID Readers
You have seen the two types of RFID readers and so which one should you go for? Here are some factors you can consider.
In terms of cost, the Parallax RFID reader is very affordable at $39. However, you need to factor in the additional cost of wiring up the unit. You need to buy a power adapter (output 5V DC), a serial cable, as well as the additional hardware needed to convert the signal to serial output. In contrast, the PhidgetRFID kit costs about $58 and includes everything you need.
Ease of Use
If you simply want to connect an RFID reader to your computer, then the PhidgetRFID is clearly an easy option. However, the beauty of the Parallax RFID Reader Module is that it allows you to connect the unit to devices other than a PC, such as an embedded controller. Using the Parallax RFID Reader Module, you can embed it in a door and write your own code to authenticate users.
While at the moment, you can't really use the .NET Framework (or the .NET Compact Framework) to write code for an embedded controller, I am really looking forward to the new .NET Micro Framework to allow me to do the job in the near future.
Both readers are similar in size, and are flat enough to be hidden from view.
To sum up, you have seen how RFID works and then learned to build a Windows application that uses two RFID readers-one from Parallax and one from Phidget. Depending on your needs, both low-cost readers offer a lot of exciting possibilities for integrating RFID capabilities into your projects. If you have not tried RFID yet, this is a good time to begin!