Building An Ethernet Connected RFID Reader

For the last few years, [Lt_Lemming] was the president of Brisbane’s hackerspace. Until several months ago, access to the local was done using 125KHz RFID tags and an Arduino board with a prototyping shield. As the hackerspace gained members and moved to bigger facilities, [Lt_Lemming] decided to build himself a more compact and advanced platform.

His Simple NetworkAble RFID Controller (SNARC) is a platform which can be connected to an Ethernet network and different RFID readers in order to implement smart access control functionalities. Through hole components were selected so even solder apprentices may assemble it. The PCB was designed using Fritzing, and development can even be done inside the Arduino IDE as ISP and serial headers are available on the board. Finally, an N-channel mosfet controls the door locking mechanism.

The project is open hardware and software, and all the sources can be downloaded from [Lt_Lemming]’s github repo.

14 thoughts on “Building An Ethernet Connected RFID Reader

  1. I can definitely appreciate this as someone who has implemented RFID for a hackerspace. I’m curious why he didn’t include series limiting resistors in the LED path. The ATmega328 can source (safely) up to 40 mA. This could kill many LEDs and if it doesn’t could eventually damage the pin driver.

  2. I’m confused. Are RFID cards secure, or not? (That’s a rhetorical question.)

    I see plenty of complaining about how insecure they are, yet hacker spaces are using them for access control all over the place. I’d expect iButtons or smartcards…not easily-cloned-especially-by-the-typical-hackerspace-user RFID cards.

    1. Only those from hackerspaces have the knowledge and equipment to copy these cards and probably they don’t have a reason to go in without anyone noticing.

      Those tags are still too high tech for any regular burglar, and after all they can just smash the window and get in through it.

  3. @Lt_Lemming this is very interesting but I was wondering why not use wifi or bluetooth instead of RFID? You could use an app on the smartphone that uses an SSH key for security to unlock a Z Wave or other computer controlled lock. Also what type of lock are you guys using for the door?

    1. Doing it via RFID makes it as close to physical keys as possible, doesn’t require someone to have a certain device on them at all times and doesn’t require they remember usernames/passwords. It’s also a lot harder to sniff something that has a 70mm range rather than something that has a 70m range.

      Z wave was something I hadn’t even heard of, so I just went and looked it up. $198 for one door lock, we do 2 or 3 for that price.

      We are using a basic electric door strike which I think I mentioned in the 2nd paragraph of the article. It means the handle and keys still work, but we can trigger it electronically as well.

      1. Sniffing is sniffing which is why I suggested using SSH. You could still use your electric strikes with a Wifi/bluetooth option. The nice thing is that you could add it to your current system if you wanted to. Just a potential cool addition to your system. BTW yes I am thinking of making the same system for my workshop eventually.

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