Conceptual idea: RFID solenoid door lock

*o* · Post by ***o*** » Wed Aug 30, 2006 4:15 am

well,

as all you know security and privacy is important.

So, picture this!

you walk up to your room there is no handle on the door, you swipe a tiny keyfob a small green light glows you hear a click and the door is able to easily swing open.

But what if you forget your RFID tag? simple! you swing open a tiny panel (in the floor (under the carpet) and you type a super secret code and the door swings open.

Simple conceptual block diagram:

RFID scanner: The scanner i plan to use is this one

Relay: Probably a 2A relay

Solenoid: This will be a custom built setup the solenoid will operate a deadbolt lock

Microprocessor: This will probably be a PIC16F84

Keypad: Something like This which will interface with the microcontroller to operate the relay. Or something like this

Reed switch: When the dorr is open the solenoid is not out but when the reed switch is closed the solenoid locks again.

The other componnent i would need would be something on the inside to open the door from the inside.

Questions:

Could anyone write the program for the microcontroller?

what would be the best microcontroller to use?

How could i make the keypad work?

How could i increase the signal strength of the RFID reader?

Thanks for the help everyone!

EDIT: or i could use something like this

Post by **Black Six** » Wed Aug 30, 2006 9:04 am

They already exist to some extent. My school uses RFID for access to some rooms. I'm not sure how secure it is, but it's there.

gamecube6 · Post by **gamecube6** » Wed Aug 30, 2006 10:20 am

there is a book on how to make it, the same publisher as ben's book it's called

"RFID toys"

search for it!

Adeptus · Post by **Adeptus** » Wed Aug 30, 2006 6:39 pm

Some of the places I've worked have had them.
They're usually referred to as "proximity card" locks (or proxi card for short...)

I'd say they're pretty secure, even the military uses them.

totokan · Post by **totokan** » Wed Aug 30, 2006 9:35 pm

I believe a company adverts in discovery or popsci or one of those science-ey mags an rfid lock mechanism. It uses RFID and has an access program for a PC. It seems to use regular handles, and key-shaped rfid tags. Basically, a simple RFID solution for the non-electronical-engineer home user.

NiN^_^NiN · Post by **NiN^_^NiN** » Wed Aug 30, 2006 10:50 pm

You can already buy a door knob which the RFID builtin it also has a external keypad which u could have under your floor if u really need it.

totokan · Post by **totokan** » Thu Aug 31, 2006 9:15 am

Wow, NiN, I thought you left... Also, I think you mean it has the rfid scanner built in, as having the RFID built in would make it so that it would do nothing except be a scannable device...

*o* · Post by ***o*** » Fri Sep 01, 2006 3:28 am

lol the main thing i like about this is the fact i could but it myself.

yeh...

does anything think it would be work ok?

totokan · Post by **totokan** » Fri Sep 01, 2006 7:54 am

I think it would work fine, but how would you program the system to recognize your tags?

sammy · Post by **sammy** » Fri Sep 01, 2006 7:59 am

A system like that is used in my city's swimming pool. It doesn't have the keypad though.

I've seen a lot of hotels that use this system as well. Would be cool to have on your door or something.

Post by **gannon** » Fri Sep 01, 2006 8:56 am

I think the easiest way to set a password on the RFID lock system would be a hex jumper matrix...although that'd mean 32 jumpers per byte of the key system

*o* · Post by ***o*** » Fri Sep 01, 2006 5:32 pm

Luckily the reader/tag dont need programming (check the link)

I think it will work however i have no idea how to deal with the keypad...Anyone know how to work with PIC's well enough to help me?

I have scavenged a whole bunch of pinball solenoids and have been hooking them up to power to see them go (ouch they hurt!) they are a bit loud but when i wrap them in foam they are quite quiet.

My only worry is catastrophic system failure (my room being uncaccessable) and i havent figured out how to prevent this yet.

Post by **gannon** » Fri Sep 01, 2006 5:59 pm

*o* wrote:My only worry is catastrophic system failure (my room being uncaccessable) and i havent figured out how to prevent this yet.

How about a saw or sledgehammer?

*o* · Post by ***o*** » Fri Sep 01, 2006 6:18 pm

i was thinking more along the lines of a backup battery vut destructions good also

totokan · Post by **totokan** » Fri Sep 01, 2006 7:02 pm

*o* wrote: I have scavenged a whole bunch of pinball solenoids and have been hooking them up to power to see them go (ouch they hurt!) they are a bit loud but when i wrap them in foam they are quite quiet.

what non-salvagable tables are you getting these from?
Also, about catastrophic system failure, just set it so that battery dead= unlocked. Or, better idea, just use a nice, big sledgehammer.
This is totokan, reminding you to protect pinball!