Mystery box! It's what you need ! Its security system is going to save your life. No more code needed, just a sync between buttons. Its alarm system warn you when someone try to open the box without knowing the right technique.
Some examples, you buy candies but you don't want your kid to eat...
The Foreboding Black Box
A group of my friends decided to make a pressure pad that would send you a text message if the valuable you placed on top of it had been moved.
2 Bit Adder (binary)
This two Bit Adder adds up to 1+1 in binary. That would equal 10 in binary and 2 in decimal (the most used base. We use it almost always). When you push both buttons the top one turns on and the bottom one stays off. One you push one or the other one the bottom one turns on and the top one turns...
Blink 300 Times Per Second
Makes your phones pics black
Lego Bitbage Truck
CLEANS small PIECES of TRASH ABLE TO FIT IN IT
With this thing, only one card will give a output. And if you use a wire into the wall-plug, you don't need to wory about the battery. You can also screw it on something. The output didn't I make because it is your job to do that.