Maker Society

Adventures In Making Things: RFID Door Opener (Part 1)

Now, if only I could combine you…

Hey Everyone! Ben, here.

So, welcome to “Adventures in Making Things”! This is the very first post in a series that I hope will catalog, inspire, share, and teach people about a project that we/I/you are/am working on. If you have a project that you would like to share, send us a write-up and we’ll post it! Without further ado, on to the project that I’m starting to work on.

The “Aha!”

Keys are a bothersome thing to have, especially if you have a few of them. They don’t quite fit in your pocket and they love to get lost if you’re out on the town or if you’re late for something.

I thought, “Wouldn’t it be great if I didn’t need to take my keys if all I had to do was get back into my house?” Boom. I’ll just make an RFID reader thing to open my door!

This little guy on the left is the gatekeeper to your house! “There is no Arduino, only Zuul”

The RFID Reader

So, the next step in making my door opener is to find an RFID reader that wasn’t going to be a project just getting it to work. I came across this reader from Parallax. It’s a little bit pricey at $43, but it comes fully assembled and has a very simple serial interface (works right out of the box). It also comes with 2 of the credit card looking RFID tags (perfect for your wallet).

There’s other setups that might have been better; Adafruit has a sweet Arduino shield that not only does RFID, but also NFC and can write RFID tags (not too bad).

The Rough Idea

So, what’s actually going on here? I like to start out with a sketch of the general idea of what needs to happen and then elaborate from there. Usually, I have to come back to the top and redesign stuff due to new obstacles, but this is a great way to get the gears turning. Forgive me for terrible art work.

The RFID reader reads the semi-unique ID of the tag and then sends it serially to a microcontroller. We’ll use an Arduino.

If you can’t tell by my art, what I plan to have happen is the RFID reader reads the tag and shifts out the ID to the Arduino serially, if the Arduino recognizes the tag then the door will be unlocked with some type of actuator. Check out this post from Sparkfun to get the low down on serial communication.

Next time, we’ll start playing with the hardware to see if we can get the RFID reader to talk to the Arduino.

 
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