Fingerprint Scanner Both Simplifies And Complicates Opening Garage Door

Fringer Print Scanner Garage Door Opener

Opening a garage door by hand is a lot of work and a hassle, hence the advent of the garage door opener. Nowadays, some people may even say just pushing the button of a remote control requires too much effort. [nodcah] is one of those people so he came up with a fingerprint scanner that controls a pre-installed garage door opener. All kidding aside, it is a cool project that lets you into your garaage, keeps unknown people out and doesn’t require you to remember to carry a key or remote.

In the center of this project is an ATmega328 that runs a custom Arduino code. This ATmega328 is responsible for controlling a 16 character, 2 line LCD screen as well as communicate with an off the shelf fingerprint scanner from Sparkfun. The fingerprint scanner has a built in CPU, can store up to 20 fingerprints and does all its own processing of fingerprint scans. It then communicates to the ATmega328 with simple commands over serial Tx and Rx lines.

The ATmega328, LCD and fingerprint scanner are all mounted outside the garage in a 3D printed enclosure. If the wires for the internal-garage open/close button were just run straight into this outdoor module, anyone could open it up, short the wires and get into the garage. To prevent this, if the ATmega328 gets the ‘OK’ from the fingerprint scanner, then it sends a signal to an ATtiny85 that is inside the garage. If the ATtiny85 receives the correct signal, it will then actuate the garage door opener by shorting the open/close button contacts. This prevents anyone from sneaking into the garage.

[nodcah] did a great service to the community by making all of the part list, schematics, instructions and Arduino code available so anyone can easily put this project together.



48 thoughts on “Fingerprint Scanner Both Simplifies And Complicates Opening Garage Door

      1. I know you were just “mocking” me for leaving a slightly negative comment on that project, but now you’ve got me an idea. I could just integrate that thing in my car. :D

        People will think that my car is so premium that it got delivered with an integrated “garage door system”

          1. I read about a project somewhere where someone wired a keyfob into their car’s power, and put a button for it under a blank button in their centre console. You couldn’t even see it was there when it was all complete.

            I got the point of your project, and I think it’s a good one. I’ve thought of doing similar with a keypad, or wiring my doorbell button for code entry on short presses, and doorbelling on a long press.

    1. if it fills in your fingerprint, it might be a problem. wet fingers would be even worse. The matching is just measuring the distances between key points, so what the image looks like shouldn’t really matter.

  1. So, I noticed quickly that this thing has 0 security. just pull it off the wall and jump the wires going to the door.

    Should have left the guts inside the garage and just run the scanner itself to the outside.

      1. WELLL…. If the thief knew it was a sparkfun scanner he could have some serial transmitter to “jack” into the outside part to send the ATMega328 the correct command and boom…. (All practicality of a thief going through that effort plummets to the bottom of the ocean)

        1. Just for fun though, there’s a solution to this, right? You add an encryption layer that has rolling code so that the key that is sent to the inside module only works once.

          That garage must be guarding something super valuable to go to this much trouble!

          1. Silly nerds, fancy thinking bad guys care about the lock.

            It’s like seeing those door bolts with hardened padlocks on them. Sure, you can’t cut the padlock with boltcutters, but those door bolts are rather soft steel… Snip snip and you’re in. Or just take a crowbar and lever them off.

          2. You mean something expensive like.. a car? and (power) tools? and maybe an unlocked door into the house?. Wow Mike.. no need to get angry at someone making a valid point, isn’t a security solution meant to be secure?.

          3. Actually, Mike, I think it’s a lot simpler than that. The scanner lets you upload and download template data for specified IDs, so all you need to do is have one ID, say 23 or something, be reserved for security and let that be a sort of verification code. That way, even if you replace the scanner with an identical scanner that recognizes the infiltrator, it can’t spoof being the original. If you really want to, you probably could change that template signature periodically too, perhaps to throw off logic sniffers…

    1. Its an optical scanner. I would assume its easily spoofed. And by easily I mean with a photocopy and a warm finger behind it. Someone would have to really want in your garage though.

      1. Does that actually work? I think that the image it scans is generated by the frustrated total internal reflection that the finger causes. I would be surprised if an image would work for that. Also… why the warm finger?

        I have one of these, maybe I’ll test that sometime. I’ve been thinking of placing one on my door now that my roommate lost his key.

        1. If it really is FTIR – you’d need a physically ridged item to fool it. Gummi bear trick (gelatine + mold etched onto pcb copper cladding based on the image of a registered print) might work.

  2. Great Version 1.0 now you need a secure case so some idiot with a screwdriver doesn’t come along and vandalize it or short some wires out and try to break in.

    My personal favorite is sticking a magnetic reed switch inside the jam of the door by drilling it our from the inside so there is no external tells, pass a magnet over that spot of the molding and it triggers, the most secure switch is the one you can’t see and don’t even know is there.

      1. Could add a rudimentary password pattern – use the magnet to activate the switch in pulses like a “secret knock”. Microcontroller on the other end wouldn’t run the lock solenoid for anyone who didn’t know the right pattern.

      2. A company I used to work for required that I give them a copy of all my customer files on a disk, which I did provide, on a 5 1/4″ floppy, that was in 2006. so yeah, security through obscurity, do you know where I could get an old TRS 8″ disk drive?

    1. That’s almost as stupid as the anti-vaccine pundits. Seriously? Thieves cutting off your fingers? There ARE easier ways to get in that doesn’t require dismemberment. Like a crowbar. Seriously man, seriously.

      1. Locks and other security are ONLY to protect you from your neighbors/friends/relatives from snooping thru your stuff. Any decent thief only needs a drill motor and a sawsall to enter pretty much any building with any type of security.

  3. Anyone other than concerned about the external unit having a fingerprint scanner that stores the fingerprint data? Who cares if the ooen signal is encrypted if one can read the valid codes. Imagine if you had more things like the front door locked down with the same brand scanner.

  4. So it’s slow, has a sliding cap, can be stolen and bypassed and needs your physical presence.

    I don’t know about this, it might be good if you hide it and use it as a backup system for when your fob gets lost/inactive, but apart from that it does not seem so handy.

    1. Slow?
      Yes, it does have a sliding case.
      It can be stolen, but I plan on covering the outside edge in silicone to make it more water resistant and harder to break into (not that they would be able to open the garage anyway).
      And yes, it does need someone to be there, for the whole point of it is to replace having a key.

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