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Topic: Make me an Arduino Timed Lockbox? (Read 7927 times) previous topic - next topic


I want a timed lockbox, so that I can lock a box and set a timer, preventing the box from opening until the time is up.  Ideally, I'd like a timer that I could set for days, weeks, or even a few months into the future.  Alternatively, it would also be fine if the box were designed for setting the time and date of desired opening as well, instead of a countdown timer -- whichever you'd advise.
I imagine it being somewhat like this:
But it doesn't need to be nearly as fancy or decorative -- a simple prefab plastic box with enough space to hold 3 stacked boxes of playing cards inside would be sufficient. 
It could be battery-powered, or plug-in (with a battery backup or a backup key lock) -- whichever you'd advise.
Doable?  Interested?  If so, what would you be interested in charging to build such a box?
I'm in Los Angeles, and a local maker would be ideal, but not at all required.


Aug 30, 2011, 01:30 pm Last Edit: Aug 30, 2011, 01:33 pm by PaulS Reason: 1




If so, what would you be interested in charging to build such a box?

Depends on how elaborate you want the box to be and how difficult you want it be to defeat the lock.

Perhaps it would be better if you looked at the electrical hardware requirements, priced them out, and then proposed a fee for programming/building the box.

Should the box show when it can be opened? Or how long until it can be opened?

An Arduino, a RTC, a battery and wallwart, an LCD, a few switches, and a servo would be all the electrical hardware needed. Some box with a hinged lid and a latch that can only be opened by the servo (or a key) would be needed on the mechanical side.

The programming is relatively straightforward. Set the clock (current date/time). Set the opening time/date. In loop(), see if it's time to open the lock. If so, rotate the servo 90 degrees.

Going to sleep, and waking up periodically, to check the time, could extend battery life.
The art of getting good answers lies in asking good questions.


Reminds me a little of that great project someone posted quite awhile ago. A person designed a 'locked box' that contained a GPS module and would only unlock on one specific point on the earth. Push a button and it would tell you only how many miles it was from the target location, but not the direction if I recall correctly. It also only allowed a limited number of inquires, maybe 50. Used sleep mode intelligently to maximize battery life and did use a servo I think unlock the box. He gave it to a couple as a wedding gift.



That's box described in the sparkfun link in the original post.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


I started building one a while back but got distracted with other duties.  Here's a link to my first 3 posts about the timed lockbox, or as I called it "The Chronobox" which I will hopefully finish up this winter.  You're free to use whatever code and information I've put up there if you decide to build it yourself.


I thought all you want is a power button and a back up coin battery to keep the RTC running. Every time you power up the box it reads the RTC, and tells you something like "Please turn me off, it is not time yet" "Or it is time, opening the box". This way the battery can last months. Apparently if the user is not decent and leaves the box on the battery drains. Then you need the wall wart to power it up.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter


has anyone out there worked this out yet?

As I am looking to add a time delay lock to a larger project.


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