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.




  1. Phrewfuf says:

    Meh. I’ve got my garage keyfob sitting in my car, so i don’t even need to get out if i want to open the garage door.

  2. Paul says:

    someone can get into your garage (possibly house) when you leave your car parked out front if you leave the transmitter in the car.

  3. adnbr says:

    Can it cope with dirty/greasy/oil-blackened fingers?

  4. CaptainClank says:

    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.

    • CaptainClank says:

      if I read the whole summary I’d have seen that he did leave the guts in the garage. disregard.

      • 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)

        • Mike Szczys says:

          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!

          • Tony says:

            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.

          • nodcah says:

            This issue comes up: But I’m still planning on encrypting it anyway =)

          • dalokin says:

            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?.

          • kristian says:

            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…

    • Rob says:

      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.

      • kristian says:

        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.

        • smilr says:

          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.

  5. Scott says:

    Why not have more of a flip-up type vibe with the cover so it just drops back down when you’re done?

  6. boot says:

    safe? take a picture en hold it front of the scanner

  7. Jack says:

    I think it should be pointed out that this guy is 15. That’s pretty awesome.

  8. Aztraph says:

    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.

  9. Alex says:

    Steal my keys, steal my key FOB, but PLEASE let me keep my fingers!

    • Eirinn says:

      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.

      • vonskippy says:

        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.

  10. bwmetz says:

    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.

  11. Whatnot says:

    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.

    • nodcah says:

      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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