Week 6

We have reached a standstill because we are not getting the circuit modulate the signal correctly.  Meaning that when we hook up the circuit to the oscilloscope and swipe our card, we are not getting a useful signal to determine differences between cards.

This signal is what shows up on the oscilloscope after we put a RFID card on there, this signal is supposed to look like a sine wave with a quick frequency change that would represent 1's or 0's.  This wave does not change for any RFID tag.  Currently we are working with fellow students and teaching assistants to figure out the problem, but are having little success. 

Week 5

Since last week, we were receiving help from an Electrical Engineer at our school.  Through his help we were able to build a smaller, more convenient circuit board.  However, when testing the board we were unable to generate any kind of nice looking signal, the reason being is unknown so we had to roll back to using a breadboard design.

Through this design we were able to generate the correct carrier wave, but wasn't being modulated correctly by the cards.

Week 4

From last week we were unable to produce any kind of wave.  However we noticed that there were some connection issues in the board, so for the mean time we were able to fix the board and produce a square wave with a period of 8ms for reading 125 kHz.  After this we need to make a more permanent board and edit some program stuff.

Week 3

In Week 3, we created a circuit board for the RFID reader as shown in the picture.  From this we attempted to create a square wave with a period of 8ms because that frequency would read at 125 kHz.  Unfortunately it didn't work so, we had to go back and check some things in the board and the program.

Week 2

Week2: We identify the most important components of the RFID reader and the physics behind them. These components consist of an antenna coil inductance and a capacitor which can produce the frequency that we need.  The equation that allows us to find the frequency is  Where L is the inductance and C is the capacitance. When a current flows around the inductance, it generates an electromagnetic field that communicates with a tag by an antenna coil inductance of that tag. When electromagnetic field enter the tag, it will induce a current that flow around the antenna coil and power the integrator circuit to get identity information, and transmitted back to the reader which is called ‘backscattering process’ .  Our goal for this week is continuing to find out other components that can connect with these two components in order to have a full schematic of the RFID reader.    

Week 1

Week 1: Research was done to have a basic understanding what was needed from us as a group.  We also split up responsibilities via each group member's strength, but the group members will still be able to help each other out with their tasks.  Dave is mostly responsible for the programming, Justin will mostly be taking care of electrical design, and Nasser will be mostly responsible for mechanical design with some implemented electrical design. Week 2 will start with circuit design.

Project Overview

Our goal is to make a RFID reader that will allow us to both unlock and lock a door.  RFID stands for Radio Frequency Identification, and is a growing technology allowing people to do all sorts of things, such as having access to certain buildings, paying tolls, and even putting them on groceries to allow faster shopping.  In this project we will be using our own Drexel ID cards and will construct an RFID reader to allow us to unlock a door that we will also construct (in small scale).  This technology could lead to a variety of things such as added home security and more.  Weekly updates will be posted so be sure to follow!