[Mike Buss] wanted to make his girlfriend something unique for her upcoming birthday — she had mentioned she wanted something to keep small mementos in, but [Mike] decided to step it up a notch on the awesomeness scale.
You see, a few years ago [Mike] read about the Reverse Geocache Puzzle by [Mikal Hart], which is an awesome box that gives you feedback as to how far away you are from the “secret” location that the box will open at — To raise the stakes however, if you ask for the distance more than 20 times it locks itself forever! Now, unfortunately, a memento box wouldn’t be very useful if you had to go to a secret place every time you wanted to open it… so [Mike] decided to secure it another way, using RFID!
It makes use of an Arduino, a Parallax RFID Reader, a micro servo, a button, an RGB LED, and a cleverly designed latch made of a metal eye hook and small copper rod. Since the box is battery powered, [Mike] has added an extremely clever fail safe mechanism. The 9V battery inside includes two extra contacts to the outside of the box via small screws. Completely inconspicuous, but if the battery is dead, simply hold a new 9V to the screws with the RFID card in place, and bam, the box opens!
We’re pretty sure she’s going to like it — check it out after the break!
I like the 9v recovery option with the screws :D
i Think this is a fantastic idea.
One that i would like to recreate…
MIke how do i go about making one?
I second that. Mikebuss, do you have a small write up?
I have a small writeup on my website ( http://mikebuss.com/2014/02/23/rfid-keepsake-box/ ) that lists the components used. I also have the complete code uploaded to GitHub: ( https://github.com/mikebuss/RFIDKeepsakeBox/blob/master/arduino_sketch.pde ). I don’t have a detailed tutorial on making one from scratch, but that should be a great start.
I’d be happy to help if you start making one and run in to any trouble! There’s contact info on my website.
Thanks!!!!!!!!
He could have used the illuminated button led as indicator
I was originally planning to, but found the viewing angle of the LED in the button was a little weird. If you were opening the box up from a normal angle, the button LED is a little hard to see.
What’s the fail safe for when she loses the RFID card in the abyss that’s likely her purse? A screwdriver under the lid?
You could add a “backdoor” also. Maybe it could open in the parking lot of a specific post office without an RFID verification as a backup
I programmed in a bunch of extra RFID tags that I have hidden away in a safe place. If all of those get lost, then we’re in trouble!
I was disappointed that the polarity of the external battery terminals was not indicated by using different screw drives. There are two very common ones that look like a plus and a minus…
Yeah, someone on Reddit suggested that too. I wish I had thought of it at the time!
Unless you have already given it to her and cant get it back, simply throw a diode or two on the screw terminals. Worst case scenario you touch the battery backwards and nothing happens.
Not really sure whether I would call using RFID secure, especially as the ones used even don’t try to do any cryptography to prevent cloning. The box itself looks awesome though.
I agree. A hammer would also make short work of the lid. This type of lock will only keep honest people out!
RFID Paper bag is secure!!!
Also the “failsafe” only works if the failure is the battery, if the hardware fails it’s hammer time again!
Those rfid tags are really small, yes? Are they small enough to put in jewelry like a necklace or ring?