GK-12 RFID Summer Camp 2004

In July 2004, Harvard GK-12 hosted 4 students from local middle and high schools to conduct a project on Radio-Frequency Identification (RFID) technology on campus. The camp was an opportunity to immerse the students in the environment that graduate students work in: hands-on access to cutting-edge technology. We had no idea how they would respond.

Here is a flyer advertising the camp:

Upon arrival, the students were given the following briefing, as well as blank lab notebooks, binders filled with papers about RFID technology, and manuals for the equipment they were going to use. We met in a conference room and the students read the following briefing (which was of course printed on Harvard letterhead). Then I gave a presentation covering the physics of RFID, current applications, potential future applications, and social concerns.

Briefing to the RFID consultant team for the Harvard Engineering DepartmentJuly 26,2004

RFID technology has been gaining increasing attention in the last couple years. Wal-Mart has stipulated that suppliers tag their products with RFID chips. Grass roots organizations such as CASPIAN warn us that RFIDs will be a major invasion of our privacy. Pundits foresee that RFID chips will become ubiquitous – unseen electronics built into a large number of the goods we purchase and work with. What parts of the hype should we believe? The Harvard Engineering Department wants to stay knowledgeable about new technologies. We have brought this team together to examine RFID technology and recommend to us if we should be adopting it for department use. In order for you to study this technology, we have purchased an RFID evaluation kit from Texas Instruments for your use. You will also have access to computers, electronics, and lab space in order to experiment with and evaluate the TI-RFID package. There are 4 major questions that we want you to answer by the end of the week:

1) How do the RFIDs work?2) How well do the RFIDs work?3) What can we use RFIDs for (based on your answers to 1 and 2)?4) How should the technology be used/introduced so that it does not raise concerns

about privacy? Is this even possible?Some of the potential applications that the Harvard Engineering Department has considered are: tagging staff for access control in engineering buildings (to prevent piggybacking), tagging expensive equipment, tagging lab equipment to speed-up inventories, keeping tracking of dangerous chemicals, automating classroom attendance, and automating checkout in the engineering libraries.

On Friday, you will present your findings to a panel of Harvard graduate students and colleagues. Best of luck.

Once introductions were completed, the students divided up into 2 groups. The first circuit design activity was to detect a light from a laser pointer with a photodiode and use the detection signal to trigger a buzzer. This introduced the concept of electromagnetic detection, but with visible light instead of radio waves. The other preliminary activity was to familiarize students with the Texas Instruments RFID system we were using. This activity is included below.

Welcome to the first RFID activity of the week. You need to learn about the equipment you are going to be evaluating. While you are doing this activity, go slowly enough to understand each step. The benefit of the activity is solely in what you learn as you go through. Also, if there is something you are curious about feel free to try it out. You only really understand how something works when you understand how it doesn’t work.

The SETUP

You should be looking at a green motherboard with computer chips on it that looks like this:

This is the RFID reader. It produces the radio-frequency waves that power the transponders, and it also interprets signals sent from the transponders. The antenna is housed in the black plastic disk:

Take a look at the two connections to the reader. What are they for?

The last part of the set-up is to organize the RFID transponders. They are located in a cardboard box next to the computer. The set we have has transponders of different shapes and sizes. Each transponder houses an antenna, capacitor, and integrated circuit. The antenna and capacitor form a resonant circuit and the integrated circuit stores the data or ID number of the transponder. Using page 3 of the “Getting Started Guide” separate and label the different kinds of transponders. As we will see, they have different functionalities.

THE SOFTWARE

Next open up the S2_util software. This is how you will interface with the RFID reader. Question: If the RFID reader has computer chips and can read a transponder, then why do you need to use a computer? What can a computer do that the RFID reader can’t do?

Once the S2_util program is open, click on ‘Operation Mode’ and ‘Micro Reader.’ Now the program is set to communicate with the RFID reader. Under the ‘RF-ID tasks’ tab there are 3 different modes: ‘Single Read’, ‘Line Mode’, and ‘Normal Mode.’

Click the ‘Single Read’ button. You should get a red message on the screen saying “no TRP detected.” Now take one of the transponders from the box and hold it right next to the antenna. Click ‘Single Read’ again. Hopefully this time you will get a green message from the software. You should also see a green light flash on the RFID reader. Try this with several of the transponders to see if they work.

Finally, try using the software in ‘Line Mode’ and ‘Normal Mode’. What happens when you click on these buttons?

WRITING DATA

Take out one of the R/O transponders. Do a single read with it. In the receive window of the software program you should see an ID pop-up after you have read the transponder.

Now select a R/W transponder. Use single read to find out the transponder’s ID. Next, in the S2_util software, click on R/W in the ‘TRP Type’ column. In the ‘TRP Data’ column type in a number in the ‘Data [hex]’ entry space. Now, with the transponder within the read range, click the ‘Program TRP button.’ If the write is successful, do a ‘Single Read.’ Look in the Receive window to see if the number that you typed into the Data box was successfully written to the transponder. Put your transponder out of the RFID reader’s range for a minute. Bring it back. Read it. Has it kept its new ID?

You have also been issued a special SAMPT transponder. This transponder works like a R/W transponder except that it has more memory. If you click on MPT in TRP Type, you will then see some new options open up. In ‘TRP Data’ you now have an extra entry to specify the Page that you want to read or write to. Each ‘page’ is a different 64-bit number. If you click ‘All Pages’ on the left-hand side and then do a read, you should see 17 different Ids listed in the receive window. By using the ‘Program TRP’ button and the ‘Page[hex]’ entry, can you figure out how to read and write to just one of these pages? (Make sure and write down the procedure in your lab notebook).

THE COUNTER

When you click the “view counter” checkbox in the “RFID Tasks” tab, the counter data appears in the lower right hand corner of the software window. Try reading and writing operations while keeping an eye on the counter data. What registers as a good count or failed count? When will/won’t this counter be useful in your experiments?

TESTING TRANSPONDERS

Try different transponders to see, for instance, how orientation or distance from the RFID antenna affects reading/writing. What modes (single, line, normal, etc.) are most useful? What can you do to block the RFID signal?

Throughout the week, students devised their own experiments testing various properties of the RFID system. Focus was always especially paid to two things: 1) how does the physics of the system help us to choose interesting experiments, and 2) how do the specifications necessary for potential applications and public acceptance compare to the experimental reality.

At the end of the week, the students presented their findings to teachers, Harvard students, and parents. Their success during the week greatly exceeded our expectations.

Rashaad, an 8th grader at Tobin MS, introduces the group and the topic. He gave an excellent explanation of how cryptography works in the RFID system.

The team stands in front of the firing squad, I mean, audience. L to R Brian, Sam, Rashaad, Liana, and Jean. We were very pleased that Liana was able to show that changing the inductance of the tags can block the radio-frequency signals.

Good times are had by all.

Unfortunately, one of the audience members received a parking ticket during the presentation. The following is what I sent to the Harvard parking office.

To: Harvard University Parking ServicesRe: Appeal for Citation # H-------

During the morning of July 30th, the Division of Engineering and Applied Science hosted a presentation by 4 high school students as part of a week-long program. That morning the students parents were invited to attend the presentation. During this time --- -- --- ------- received a parking ticket. I had not discussed parking or visitors’ permits with --- --------- -------, and I would like to ask that the ticket be excused.

Here is my contact info:Brian MurphyHUID --------Phone 617 23- ---- (cell) 617 --- ---- (home)Local address: ---- Massachusetts Ave ----

Cambridge, MA 02138Email address

bmurphy@fas.harvard.edu

Here is the ticket info:Citation #: H-------Location: DEAS LotLicensce plate: ------

Please feel free to contact me if you need more information. Dr. Kathryn Hollar, director of educational outreach programs in DEAS, can also be reached for information about the activities on July 30th. Her email address is hollar@deas.harvard.edu.

We were able to reduce the amount of the ticket from $15 to $7. Fight the power.