Perfect safe #bitify

by msgre

Published on October 4, 2014

Do you dream about safe which holds securely all your gems? Just imagine it — strong case, big numbered wheel on door and secret passcode that nobody knows (except you naturally). You don't need travel to New York and register at JP Morgan's Vault on Manhattan. Just sit in you room and make you own safe! 

Perfect safe is built from Arduino module which take care about passcode set through dimmer module, servo which control lock mechanism and few other parts (buzzer, LED, switch). You could find updates and technical information on GitHub project page. How does it work Arduino (w6) is the heart of the safe. If you set correct passcode through dimmer (i6) connected to analog port A1 it will set HIGH state to servo (o11) on D9 pin (servo must be set to TURN mode) and doors of the safe became opened. Arduino also turn on long led (o2) connected to D5 pin — put this light inside safe, so every time you open it you will see every piece of your gem collection. Say NO to that old dark safes! There is also buzzer (o6) connected to pin D1 which beeps every time you set some value on dimmer (i6). You need feedback, don’t you? Just turn dimmer to some position and wait. Arduino reads value from dimmer each 200 ms (5 times per second!) and if it is stable for approximately 1.5 seconds it takes it as one of the passcode numbers. Default passcode is 295 but you could change it to own value. But keep in mind that your passcode could not contain two same numbers following each other (for example 123 is OK, 112 is not). The last bit is roller switch (i19) which is inside safe and read information about state of safe doors. When you have opened safe and close it again, this switch send that info to Arduino and it will lock doors with help of servo.

Credits: Jindřich, Františka

How To Make It


Build lock mechanism (we make it from LEGO parts). Connect it to servo and fix it (ducktape is your friend). Watch second video on this page for inspiration.


Construct safe box around lock. Be sure that you have enough space inside because you must put there all the modules.


Build door and install dimmer on it. There must be switch in the box, which will be on when door is closed and off when opened. Try to put there some spring from old ballpoint (once the servo mechanism open the lock, spring help doors to be opened).


Connect all littleBits modules together (maybe you will need several wires modules to connect it; it depends on you construction).


Connect power to modules and upload code into Arduino.


Calibrate numbers on wheel according to steps on photo above.


Done! After you connect safe to power, it locks door and wait for the right passcode.

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