Wednesday, July 10, 2013

Build A Rfid Based Electronic Security System

RFID security systems are safer and more practical than your typical lock and key.


An RFID (radio frequency identification) security system is perhaps the most convenient security system you can create. It can be used for many kinds of special problems, especially when dealing with security. From calculating the number of items inside your refrigerator to tracking a vehicle, the uses of RFID are limited only by your imagination. One simple way to use it is to build a basic RFID door lock.








Instructions


Installing the Deadbolt


1. Install the power deadbolt on the door using the instructions that came with it.


2. Figure out where you want to position your RFID reader. You will want to place it as close to the deadbolt as possible, because wires must run between the reader and the deadbolt. The reader can be placed on the side or bottom of the deadbolt's faceplate; just ensure the wiring connectors are facing out towards the deadbolt. Failing to do so will cause the wire to hang out of the reader, causing the security system to become an eyesore.


3. Bend the edge of the faceplate slightly where the wiring connectors will meet using your pliers. Place a piece of cloth between the faceplate and pliers so you will not scratch the faceplate. Ensure the wires fit under the bend you created with the pliers.


Wiring the RFID Reader


4. Notice four pins are standing out on the RFID reader. These four pins are actually the four different functions of the readers itself: Common Collector Voltage (VCC), Enable, Serial Out (SOUT), and Ground (GND). Tie the Enable pin to the Ground pin by soldering a cable between the two. Keep in mind you will want to do this on the back of the jumper block so the wire connecting the two does not get tangled with your other wires.


5. Solder a wire to each of the VCC, SOUT, and GND pins. Ensure the wires have a little extra length to them so you do not come up short with your wiring later in the project. Trim the pins back so nothing keeps your reader from lying against the faceplate.


6. Run the wires through the deadbolt hole along with the wiring for the electronic deadbolt. Ensure your reader wires are under the part of the faceplate you pulled so they will not crimp. Make sure the wires are out of the way of the deadbolt mechanism as well. Screw the deadbolt and the reader onto the door.


7. Cover the large plastic project box. Sit the cover over the reader and mark the spot where the wires exit. Trim the plastic off of this spot in the same way you did this for the faceplate. This will keep your wires from getting smashed and possibly damaged.


8. Screw the cover onto the door as well, ensuring that it is as close to the faceplate of the deadbolt as possible. This will ensure the wires are covered up and protected as much as possible.


Installing the Deadbolt Control Box


9. Pull your RFID wiring through the hole in the back of the keypad toward the front. Next, connect the keypad connector block to the pins provided. Make sure your wires are clear of all moving parts and screw the control box into the door. Connect the deadbolt to the circuit board.


10. Examine the circuit board. Two contacts should be on the circuit board that says 'open' and 'close'. Solder two wires to the left side of the open contacts. Test the power bolt to ensure you soldered this board correctly. Insert the batteries into the deadbolt and touch the ends of the two wires together. This should cause the deadbolt to unlock.


11. Place the faceplate back onto the system once you are positive the wires unlock the deadbolt. Pull the two 'open' wires either through the side or the notch provided.


Building the BASIC Stamp Carrier Board


12. Solder the 24-pin IC Socket, with the notched side being at the top and the reed relay to the carrier board. Set the voltage regulator next to the IC socket. Solder the input lead on the voltage regulator to the VIN pin on the stamp (pin 24 on the IC socket) and then the ground pin on the regulator to the VSS pin on the stamp (pin 23 on the IC socket).


13. Solder roughly 4 to 8 inches of DC-capable wires to the VIN and VSS pins on the regulator. Use your best judgment when figuring out the length, because it will be different for every individual. It is better to go too long than too short. At this point, every pin on the voltage regulator, besides the output pin, should have something attached to it.


14. Connect this to your RFID reader by soldering the VCC lead wire from the reader to the output pin on the voltage regulator.


15. Solder the SOUT wire to pin 18 on the IC socket (I/O pin 13 on the stamp). Take the remaining wire from the reader, the GRD wire, and attach it to the GRD pin on the voltage regulator.


16. Connect the deadbolt control box. Solder the 'open' switch wires to the two switched pins on the reed relay. It does not matter which ones you pick. 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). Solder your protection diode over the leads. Take the diode and solder the end with the colored band to the coil that is connected to pin 14. Then solder the opposite side to the colored band to the lead that is connected to GRD.


Finishing Touches


17.Program your BASIC microprocessor. The easiest way is to buy a microprocessor that can be hooked up to your computer for easy programming. With the use of a battery, you can download the programming needed (see Resources) and make a few tweaks using the program BASIC Stamp Windows Editor (v2.5). Input the number of tags (people) 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 your door.


18. Insert the microprocessor into the carrier board. Make sure you line up pin 1 on the microprocessor with pin 1 on the IC socket. Power it up by connecting the 9V power to the DC power leads attached to the VIN and VSS on your stamp.


19. Test the deadbolt. Wave an authorized tag over the reader, which should unlock the deadbolt. Put the carrier board onto the remaining project box. Cut a tiny notch to let the cords through without them 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.








20. Use wire gutters or tape to support the power supply. Run the wires along the door to the adapter.

Tags: voltage regulator, carrier board, circuit board, Make sure, RFID reader, security system