Turn your Arduino into a Magnetic Card Reader!

Everyone has used a magnetic card reader, I believe. I mean, who carries cash these days? They're not difficult to get your hands on, either, and during a trip to my favorite local electronics shop, I found a bin full of these guys. So....of course, I picked one up and brought it home to see what sort of stuff I could do with it and an AVR.

This instructable will show you how to connect a Magtek magnetic card reader to an AVR or Arduino/clone and read data from the first track of card. Buckle your seats; magnetic card readers have a high bit rate!

Step 1 The Equipment List

Here are a few things you'll need to get started.

• Magnetic card reader (Mine is a Magetk 90mm dual-head reader. $5.00)
• AVR, Arduino, or clone (ATmega328p ~ $4.30 from Mouser.com
• solderless breadboard
• some wire
• maybe a header if you like that sorta thing.
• something to read your serial port. I use AVR Terminal from BattleDroids.net

That's all you should need to get started. Depending on the magcard reader you end up getting, you may have to modify these instructions, and most assuredly the code, to work with your specific reader. However, the code I've written should get you pretty far, I hope.

Comments

[Build_it_Bob]

Awesome work on this. You explained all the steps in a way that takes something that is compli cated and kept it interresting all the way through. I didn't know much about what was on a stripe and now I have at least a basic idea . Thanks for the education!
Build_it_Bob

[nevdull]

Thanks for the kind words! I'm glad you were able to learn something from it and I appreciate your comments!
Cheers!
-gian

[SpiralEdge]

I'm new to electronics and got lost at the part where the coding begins. How did you connect the card reader to the computer in order to read data from it?

[nevdull]

I connected the arduino through wires connecting the serial interface of the magnetic card.

[pdrocb]

Hello! Thanks fo your post!

I have an Arduino... but normally you have a .pde extension in the .zip i dont see any. Can you please help me, how can I use your code into Arduino.

Thank you!

Another question did you use a Magtek MiniWedge Stripe with RS232 or usb or keyboard?

[nevdull]

This code isn't from the Arduino IDE nor does it compile into an arduino PDE file. This is normal code written in C that can run on a wide range of ATmega devices, including the Arduino. However, my guess is, you will require a programmer to download it into flash just like with the other atmegas. Sorry for any confusion there.

Re: your other question. My magcard uses a serial protocol that I describe in this instructable. It's pretty standard but doesn't use USB. I had the Arduiono redirect output to a windows terminal via RS232.

Good luck!

[CoolKoon]

Could you by any chance get one with a similar price that could write these cards as well? :P I could really make use of one :P

[Spaceman Spiff]

Identity Theft anyone? Just kidding, ha ha ha.

[CoolKoon]

Nah, I hate magnetic cards and would love to develop a way to introduce some false information on them (in a BOFH way) :D

[nevdull]

Well I agree, in that it would be kinda geeky fun to have mag cards that were written with the info you wanted (and or encrypted) for testing on home egress, maybe a small sub-zoned area inside your house protected by mag card

[hintss]

I like iButtons for that.

[CoolKoon]

Yeah, but I'd need a writer for that as well. I suppose yours can't do that, can it?

[nevdull]

No, my mag card device is a reader-only. Check ebay for some reader/writer combos, although for raw bang-for-your-buck, 125khz RFID reader/writers are only dollars (for the chip, you'd have to build the circuit). Tough decision to make if you're really settled on magnetic cards.

[CoolKoon]

I'm not really settled on mag cards, but haven't seen RFID writers either. I could make use of one too :P

[nevdull]

You'll find RFID writers on ebay again, and at futurlec.com, i believe.  But why buy one when you can build one with the Atmel U2270B RFID basestation in a chip for a coupla bucks.  Yum yum.

[CoolKoon]

Thanks for the idea! I even managed to find such chip at a local supplier. I'll see whether I can make it into something useful ;)

[nevdull]

awesome! Good going, let me know how it turns out!

[ducktape3618]

awesome to hack my dad his new credit card!

[jcouch1227]

Anyone know what that red thing is called, a header? the thing in the second picture above. thanks

[nevdull]

It's a right-angle 7-pin male header, to be precise. :)
Cheers!
-gian

[akrolik]

Is there a link as to where a $5.00 card reader can be purchased?

[nevdull]

I got mine from a local electronic shop here for $5 each. I don't know if they have an online store, but their website is:

http://jbsaundersco.com/

Good luck!

[bonez13]

Sweet, being looking for project like this...

[nevdull]

[limerick]

must say though that in general, rfid is more secure in a sense, than keypad codes as with a card, you have to have a physical credential versus a keypad code which an be obtained in several ways from 'shoulder surfing' to someone
telling another, to some dufus writing it down and misplacing it and it falls into the wrong hands.

[needtobuild]

Pretty sweet !
It would be cool to make a door lock for a house with this =)

[nevdull]

Haha yeah. I've had my mind on a magnetic card reader or an RFID reader for some ingress/egress control for a little while now. There are electronic mechanical door locks at Home Depot for ~ $120.00. Couldn't find them much cheaper online, either. But it'd be a great investment. :)

[TheSodaJerk]

You could build a pretty solid electromagnetic door lock pretty easily, and those things hold like beasts

[limerick]

@TheSodaJerk:

the maglocks are they are called in the locksmith/access control business
come in a number of holding force pound ratings. 300, 600, 1200, 1500 & 3000
# ratings. And they are NOT positive latching, meaning that they have to have CONSTANT power to hold. If power fails, you need sufficient battery backup amp hour capacity. hope that info helps.

[nevdull]

That would be awesome. What sort of power requirements would you need for that? I remember looking at electromagnetic locks a looong time ago and they had two versions: one for indoor doors and one for outdoor doors, and I thought I remembered the outdoor ones had a special power requirement to hold that many footpounds (if that was the measurement, it should be newtons) of force.

[dannydutton]

Yeah, it wouldn't be that difficult. All you would need is a heavy duty solenoid, a relay, and probably some sort of hardware from an old deadbolt.

[limerick]

@dannydutton - yes, it could be done. truly in a hacker spirit. you'd need to fabricate a contraption to rotate on a limited basis - a flat tailpiece to drive the bolt, and use the solenoid to drive said contraption. then of course there is your
control system. certainly doable! :)

[nevdull]

I have in my head a difference between electromagnetic door lock and an electronic mechanical door lock. I think (and tell me if I'm off base here), that TheSodaJerk is talking about an electromagnetic door lock (the locking mechanism is provided by electromagnets.no bolting), and what you're talking about (a moving deadbolt-type-of-thing that is moved electronically). Either one would be pretty spiffy.

[carpe_noctem]

sounds right. I'm in russia and all the soviet era apartments (pretty much all the apartments i think) have a "domofone" at the front door, which is a magnetic lock (no latch, just a beefy electromagnet and plate), some console for calling apartments, and magnetic keys and the reader. the keys are little disks in a plastic holder that allows you to put them on a key ring, not cards.

[WillTheRescue]

http://www.instructables.com/id/Nintendo_Keyless_Entry_System/?ALLSTEPS

Stumbled across this.
A good starting point?

[nevdull]

Haha nintendo! That's pretty cool :)

[TheBestJohn]

Electromagnets and magnetic cards are not an overall good paring.

[limerick]

in close proximity, that is certainly TRUE! :) good bye/scramble whatever info is encoded on your magnetic strip.

[xarlock667]

So, there you are, all set to go inside your house, and your card is demagnetized. Or the power is out. (With a magnetic lock, your house could be unsecured.) Electro mechanical is the way to go, but it is still useless. All that security is for nothing if I can get in your window, go through your garage, pop the face off the lock plate and bypass your circuit, or in the case of a electromagnetic lock over power the magnet with another magnet. Mechanical locks are cheaper, last longer, and do not demagnetize. Further they do not tell thieves you have anything worth protecting.

[mutput7]

You sound pretty pro at this sort of thing...