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How to Build Your Own RFID Door Lock: "
A person's home is his castle. While most of us can't equip our castles with
the traditional means of security like moats, turrets, and iron
maidens, you still can spruce up and secure your place with the use of some
more modern technology. This high-tech option might not be as visually imposing
as an alligator-filled moat, but it still can be an effective means of keeping
out invading hordes. No, I'm not talking about lasers
or anything else quite so complicated (or dangerous, for that matter). What
you need is an RFID door lock.
RFID technology
already is used as a means of security in many different forums, so it isn't
a big leap to bring this technology into home applications. You can set up an
RFID door lock several different ways, but I'll cover the simplest way here.
One big thing to remember is that you absolutely want to set up this system
with a backup, so that you can gain entry if you experience a power outage.
Getting locked out is bad enough, but getting locked out when you had an alternative
method to get in is worse, so plan ahead.
This system for setting up an RFID lock is a standalone method, meaning it
doesn't need to be hooked up to a computer to work. While the idea of having
everything in your house wired to your computer might sound cool, and heck,
might actually be cool too, this is a much more versatile system that will save
you some wiring hassles to connect your computer to the door (unless you want
to keep your computer right by the door, then by all means hook them up.) You
can find instructions on how to hook up that kind of system here.
Materials and Tools
In order to start you're going to need to get your hands on a few basic electronic
components as well as some RFID-specific ones. You will need:
Step 1: Install the Deadbolt and RFID Reader
Once you have your materials handy it's time to start getting your system hooked
up. For simplicity's sake, I'm going to assume that the door you're installing
this lock on already has a deadbolt that you're replacing with the RFID deadbolt.
If it doesn't, I won't go into how to put in a deadbolt, but any deadbolt you
purchase should come complete with detailed instructions on how to install it.
You also can consult the ever-knowledgeable Internet
[Video/Audio]. I'm going to assume that if you're able to build an RFID door
lock that you'll be able install a deadbolt.
Providing you've got the door prepared to put the deadbolt in, you'll need
to get all the parts of it together. You'll replace the old deadbolt by putting
the power deadbolt in its place. Once you've got the deadbolt and faceplate
in the place you want it, you'll need to figure out a good orientation for your
RFID reader. Ideally, you'll want to place it as close to the deadbolt as you
can, as wires will need to run between the RFID reader and the deadbolt. You
can place the reader either on the side or to the bottom of the deadbolt faceplate,
but make sure that your wiring connectors are facing out towards the deadbolt,
or you'll see some ugly wiring hanging out. Don't screw anything down just yet,
as you'll need to lift it up in a minute.
Now you need to make room for the wires to go under the faceplate. Break out
your trusty pliers and use them to bend up the edge of the faceplate just a
tad where the wiring connectors meet it. Place a piece of cloth between the
faceplate and the pliers to avoid scratching up your shiny new faceplate. Check
the wires to make sure they fit under the slight bend.
Step 2: Wire the RFID Reader
Your RFID reader now needs to be wired to the electronic deadbolt. You should
see four pins standing out on the edge of the reader, and those four pins correspond
to 4 different
functions: Common Collector Voltage (VCC), Enable, Serial Out (SOUT), and
Ground (GND). First, tie the Enable pin to the Ground pin by soldering a cable
between them. You'll want to do this on the back of the jumper block
so that the wire connecting the two doesn't muck up your other wires.
Next, you'll need to solder a wire to each of the VCC, SOUT, and GND pins.
Make sure the wires have a little extra length to them, as you don't want to
come up short later. After the wires are soldered, trim the pins back so there
won't be anything to keep your reader from butting up against the faceplate.
Next, you'll run the wires through the deadbolt hole along with the wiring
for the electronic deadbolt. Make sure your reader wires are under the part
of the faceplate you pulled up so they won't crimp. You also want to make sure
the wires are out of the way of the deadbolt mechanism. Then, you can finally
screw the deadbolt and the reader onto the door.
To finish this part of the project, you'll need the cover for your large plastic
project box. Sit the cover over the reader and mark the spot where the wires
exit. Trim the plastic off at this spot, much like you did for the faceplate,
to keep your wires from getting smashed. Then, you can screw this onto your
door as well. Again, make sure this is as close to the faceplate as possible.
You want the wires to be covered as much to protect them from the elements and
from any other sources of damage.
Step 3: Install the Deadbolt Control Box
Now you'll need to connect your deadbolt control box to the keypad. First,
pull your RFID wiring through the hole in the back of the keypad towards the
front. Then you can connect the keypad connector block to the pins provided
(this should be pretty self explanatory, there's only one place these wires
can go). Make sure your wires are clear of all the moving parts and screw the
control box into the door.
If you're using the Powerbolt deadbolt as recommended, it should be easy to
rig up to use RFID. There should be two very clearly marked 'Open' and 'Close'
contacts on the circuit board. You'll want to solder two wires (again, make
sure they're extra long) to the left side of the 'Open' contacts. Now, if you've
done this right, you should be able to test the lock. Insert some batteries
into the deadbolt and touch the ends of the two wires together. This should
cause the system to spring to life and unlock the deadbolt. If it works, give
yourself a little pat on the back. If not, perhaps a little smack on the forehead
would be appropriate.
Now you can put the faceplate back on the system, but make sure you pull the
two 'Open' wires either out through the side or through the notch provided,
it's up to you.
Step 4: Build the BASIC Stamp Carrier Board
Now to the fun part! This is where you'll get to put together all your little
electronic components. This can be a bit confusing as it's the most complicated
step, so make sure you take it slow and step by step to avoid any mistakes.
Next you'll connect the deadbolt control box to the mix. Solder the 'Open'
switch wires to the two switched pins on the reed relay. It doesn't matter which
you solder where, so take your pick, you can't mess it up (well, I guess you
technically could, but you'd really have to try hard).
Now, you've need power going to the reed relay. Solder one of the coil leads
to pin 14 on the IC socket (I/O pin 0 on the stamp) and the other to pin 4 on
the IC socket (the second VSS pin on the stamp and the GRD). Once these leads
are connected you can solder your protection diode over the leads. This isn't
just for the fun of soldering something else. You must have this part to keep
the electric current from damaging your components when you cut the power to
the relay.
Take the diode and solder the end with the colored band to the coil that is
connected to pin 14. Then solder the side opposite the colored band to the lead
that's connected to GRD. All you need now is to finish up!
Step 5: Finish Up
Only a few more things to do and you'll be done. You'll need to program your
BASIC microprocessor. The easiest way to do this is to buy a microprocessor
that can be hooked up to your computer for easy programming. Then, with the
use of a battery, you can simply download the programming needed from
the web [BS2 file] and make a few minor tweaks. You'll need to input the
number of tags you have authorized to open the door, as well as load in the
IDs for each of those tags to make sure they can open the door.
Once it's programmed you'll need to insert it into the carrier board. Make
sure to line up pin 1 on the microprocessor with pin 1 on the IC socket. Then,
power it up by connecting the 9V power to the DC power leads attached to the
VIN and VSS on your stamp.
Now, before you finish up, give it a test run. Wave an authorized tag over
the reader. It should unlock the deadbolt.
You can now finish up by putting the carrier board in your remaining project
box. Again, you'll need to cut a tiny notch to let the cords through without
getting pinched. Hot glue the carrier board to the project board cover, then
put the lid on and screw it shut. Attach the box to the door using screws or
glue.
Finally, you'll need to find a way to support the power supply. Wire gutters
or even tape can work to run the wires along the door and to the adapter. And
that's it! Simply plug it in and you're finished.
RFID doesn't need to be limited to commercial security
measures, as it can be a great project for your home as well as a spiffy
bit of technology. So, while you may not have had the glory of installing a
castle-grade security measure, you can at least impress your friends with your
soldering skills and your ability to open your door with a wave of a hand.
"
(Read Original Article - Via RFID Gazette.)
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