Multiple rings with multiple readers for integrated house?

  • So I'm looking to be a little ambitious (well, maybe really ambitious) but I wanted to set up an NFC based system for my house that's easy for the other two Luddites that live there to use. Essentially I wanted to have three rings, one for each person, and three backup NFC cards (in each of our cars in case we lose/forget our rings and the door is locked). All six NFC devices would be used to lock and unlock the front and back doors (I'm gonna be testing with just the back door first). On top of this (because managing more than one ring for my elderlies would be a nightmare) I wanted their rings to interact with certain other NFC readers installed around the house for various purposes (as an example, my mom's ring being able to login to her laptop). Now the kicker is that I know very little about NFC tech, and only the basics of programming and hardware (I'm an avid learner for things like this), but I'm willing to build all my own readers and program them and whatnot with the right guidance. I know the idea is pretty far fetched, but it's something I'm determined to do (for the sake of my parents and my own sanity). From what I understand, there are readers that use the ID of the tag/ring for activation rather than the tag/ring having metadata written to it (which as far as I've been told would prevent my idea from working). So I guess the primary question is: Is this possible? After that we can work on the how. Any help is appreciated!

  • Community Helper

    Hi @UnrealDonnie, yes this is entirely possible!

    The verified working Samsung door locks use UID of the ring, so there's no issue there. Once the ring is programmed into it you're good to go. Just be sure you don't get one of the verified not working ones.
    There's a project here which would be perfect for laptop logon, and if you were to do it with one of the smaller iterations of arduino leonardo like the beetle then you could conceivably even fit it inside the laptop case.

    There'd really be no need for the backup cards as the Samsung units also have a pin entry method if necessary and the laptop logon can fall back to simple password entry.
    If you did build your own door locks then I'd recommend an arduino driven electric catch which would let you fall back to using a spare key if necessary. You see those on a lot of government buildings, where the doors have locks but if you swipe a card you can then push the door open without actually unlocking it. This can be problematic if you use 'proper' dead bolts that won't allow self-closing.

  • Perfect! Once I get my ring I'll start testing everything out with my side door and once I get everything set, I can move to implementing it throughout the house. Also, what are good NFC readers that use the UID? I'm pretty much just going to see how much I can automate things with a single ring to streamline stuff, so if I can find a good set of boards (at various sizes) I can try some projects (like eventually building a NFC entry system for my car)

  • Community Helper

    Most of us have had excellent results with the Elechouse PN532 V3 unit which you can set to connect to an arduino via I2C. This is what I've done in my car starter, and what was done with the desktop logon unit I linked to earlier.
    These can be ordered from Elechouse, I wouldn't recommend ebay or any other site as there do seem to be a lot of clones out there that look the same but don't function near as well.

    Depending on your programming knowledge or how much patience you have you can set up your arduino sketch to deal with UID only, stored data, or both.