Greg Gilmour is a tinkerer. He's also a gun owner. He had his mind set on a biometric gun safe, because Greg is a responsible geek, and, after all, such weapon storage "is something straight out of a James Bond film," he says.
If you're not familiar, a biometric gun safe is simply a safe that's unlocked with fingerprints. No keys, no passcodes, no PINs--just your fingerprint. It's a secure way to go.
The thing is, they're expensive. Being something of a geek like the rest of us here at Crave, Greg thought that he could build his own. And he did.
He found a Craftsman Fingerprint fingerprint-reading garage door opener in a clearance bin. He reasoned that the scanner simply scans a print and, if recognized, sends a usable signal to a switch that opens the door. He figured he could find a nonworking pistol safe that would take just such a signal. And he was right: a little digging on eBay scored him an electronic gun safe with a broken keypad.
He had both parts of his biometric gun safe in hand, and now he had to put it together.
Using some off-the-shelf diagnostic tools, Greg, who lives in Iowa, found the part that sends a signal to the transmitter of the garage door opener. It sends a signal only when a fingerprint is a positive match. That was perfect. The only hiccup was that the reader also sent a pulse when turned on. That pulse would trigger the lock, meaning a thief would simply have to reset the thing to get the valuables. That's no good.
So, when faced with a problem, Greg did what any good geek would do: he went to the Internet. And the Internet told him that he could easily program and implement an Arduino microcontroller to differentiate between the on signal and the positive-match signal.
After a tutorial and a few lines of code, Greg was good to go. The scanner passes the affirmative signal to the lock via the Arduino. The Arduino takes the signal, and if it's above a certain strength, it passes it on to the lock, which triggers and allows the safe to open.
It requires two sets of batteries--one for the lock and one for the scanner--but it was cheap, it works, and more importantly, it's way cool.
For more info, including a schematic so you can make your own, check out Greg's Web site.
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