Simple lock project (kit available too) –
There are six (or more) push switches. To ‘unlock’ you must press all the correct ones at the same time, but not press any of the cancel switches. Pressing just one cancel switch will prevent the circuit unlocking. When the circuit unlocks it actually just turns on an LED for about one second, but it is intended to be adapted to turn on a relay which could be used to switch on another circuit.
26 thoughts on “Electronic lock project”
Comments are closed.
ADVERTISEMENT
Support Make:
Join Make: Community Today
Join Make: Community Today
Soooo…. to unlock it, you only have to unmount the front, look at the wires, push the correct buttons and you’re in…. Or if you’ve made the lock, it’s easy enough of course.
Cool.
– Unomi –
I was thinking of making a passive version of this for a motorcycle ignition lock (when my keyed ignition lock started misbehaving).
All you’d need would be a bunch of toggle switches in series, mounted randomly up or down. If you were worried about people being able to tell which side was ‘on’ (as there’s usually a notch on one side of the barrel) you could use SPDTs wired randomly to one side or the other.
Never got round to doing it, though, WD40 did the job in the end.
I want to see a simon says-esque entry sytem, it plays a sequence, you repeat and it lets you in…
not very secure, but a lot of fun
@Unomi
That comment applies to pretty much any lock. As soon as you gain physical access inside the lock, you gain access to the area secured by the lock. A lock is just security through obscurity.
A more interesting problem with this lock is that the correct buttons wear quicker than the cancel buttons. Therefore, after some time, anyone can see the right combination from the front panel. I know a place where everyone has an electronic key and a 4 digit key code. The keys are unique but everyone has the same code. The lock panels have all 10 number buttons but 4 of them are totally worn out. Instead of 10000 combinations that leaves 24. Pretty easy to pick if you can steal a key.
@ Unomi- most access covers, if easy to open or placed in remote areas, have a contact that sounds the alarm when tampered with.
As far as the button wear- Make covers that are easy to re-arrange and/or replace. Maybe be tricky and “age” the button covers on the cancel switches to fool the wanna be intruder.Or have jumpered connections, easy to reconfigure, if a permanent code is not necessary/desired.
A neat MAKE on this would be to have a small rock wall, and have many of the rocks be switches. Using the jumper method, reassigning the access rocks to allow for wear would be simple.
All this discussion about tamper switches, etc is rather moot – this is only suitable for ‘toy’ use, certainly not for actually protecting anything of value. Why? Combinatorics…
If it is known that only 3 buttons out of 6 make up the combination then there are only 20 combinations that need to be tried. Even if this information was not known starting from 1-button combos and working up (to 3) would require a maximum of 41 tries (and 63 if 1 to 6-button combos were tried).
Considering a child’s 3-digit bike lock has 1000 combos, this system is hardly suited to any meaningful security application. Of course I realise that this may not have been the authors original intention, but it certainly has been proposed by others (motorcycles, tamper-proofing, etc)
However, if this is taken to a bigger scale than the rock wall and the buttons are stones about the size of a baseball/softball, even with an easy solution, it would be great for hiding the mechanism in plain sight. The door would be opened by stepping on the right combo of stones. Come to think of it, the rock wall would work just as well!
Why use any electronics if you’re going to hardwire the combination in? Just use normally open and normally closed switches that have to be pressed in the correct combination for a circuit to be completed.
With a PIC, wouldn’t it be possible to require that a certain set of buttons be pressed (the lock as it is) but after pressing the right combo for a pre-set amount of time you are required to press another set of buttons, and then possibly a third, exponentially expanding the possible combinations?
Or, have the lock open when the right combo is pressed for a specific amount of time, not too long and not too short, with a tolerance of half a second or so (adding an invisible variable to the possible combos). This type of project seems to have potential in terms of being able to create a DIY custom access control, using some or all of these possibilities (example: the buttons are disguised in your home’s address numbers, which you have to press some of for a certain amount of time followed by another set of numbers for a different amount of time; I press 1234 for 1.5 seconds, then 4321 for half a second, which wouldn’t be any longer than fumbling with keys and the multiple codes required solves the problem of visibly worn-out buttons as the codes could use them all).
I guess these ideas are outside the scope of this particular project as it was designed, but it seems to have encouraged some brainstorming and that’s what it’s all about!
With a PIC, wouldn’t it be possible to require that a certain set of buttons be pressed (the lock as it is) but after pressing the right combo for a pre-set amount of time you are required to press another set of buttons, and then possibly a third, exponentially expanding the possible combinations?
Or, have the lock open when the right combo is pressed for a specific amount of time, not too long and not too short, with a tolerance of half a second or so (adding an invisible variable to the possible combos). This type of project seems to have potential in terms of being able to create a DIY custom access control, using some or all of these possibilities (example: the buttons are disguised in your home’s address numbers, which you have to press some of for a certain amount of time followed by another set of numbers for a different amount of time; I press 1234 for 1.5 seconds, then 4321 for half a second, which wouldn’t be any longer than fumbling with keys and the multiple codes required solves the problem of visibly worn-out buttons as the codes could use them all).
I guess these ideas are outside the scope of this particular project as it was designed, but it seems to have encouraged some brainstorming and that’s what it’s all about!
With a PIC, wouldn’t it be possible to require that a certain set of buttons be pressed (the lock as it is) but after pressing the right combo for a pre-set amount of time you are required to press another set of buttons, and then possibly a third, exponentially expanding the possible combinations?
Or, have the lock open when the right combo is pressed for a specific amount of time, not too long and not too short, with a tolerance of half a second or so (adding an invisible variable to the possible combos). This type of project seems to have potential in terms of being able to create a DIY custom access control, using some or all of these possibilities (example: the buttons are disguised in your home’s address numbers, which you have to press some of for a certain amount of time followed by another set of numbers for a different amount of time; I press 1234 for 1.5 seconds, then 4321 for half a second, which wouldn’t be any longer than fumbling with keys and the multiple codes required solves the problem of visibly worn-out buttons as the codes could use them all).
I guess these ideas are outside the scope of this particular project as it was designed, but it seems to have encouraged some brainstorming and that’s what it’s all about!
(sorry about the #$!#!! multiple posts, I kept getting “comment submission error” and a blank page that loaded halfway then stalled)
A genuine Louis Vuitton Online Store purse.Buy Louis Vuitton is one of the most counterfeited brands in the fashion world due to its image as a status symbol.Now we have great discount for our
Louis Vuitton Sale.
Louis Vuitton Handbags is one of the world’s leading international fashion houses.
Louis Vuitton Bags sells its products through standalone boutiques.Louis Vuitton Outlet is one of the World’s most recognized brands. Louis Vuitton Online A long time symbol of prestige and wealth,The Louis Vuitton Purses Brand and the famous Louis Vuitton Outlet Store monogram are among the world’s most valuable brands.