Cute, but I find it odd that there apparently isn’t a direct input button for each binary digit, but I guess it doesn’t matter.
Now all it needs is a nice case of some sort.
Great way to establish geekness.

@Cynyr if you press two buttons at once it will do nothing at all because that option is not defined in the code.

when hipsters will learn to control serial LCD displays ?

Very cool. Great device.

@vadim

So you set the rows high, and read the columns and then the columns high and read the rows? If so couldn’t the state of the switch change between reads (yes i know it takes a very short amount of time to do both reads, and I’m not sure a human could do it)?

If you don’t swap highs and lows, how can you know which row/column was pressed, as you are only sensing rows or columns?

Also I read the bit about charlieplexing switches, but that method seems to require a diode per switch.

Cool. Any plans on designing and publishing a board? This would be a great educational project for just about anyone interested in electronics/computing.

Would be cool with 40XX ics :D
or relays :D

This is great. It’s one of the first programs they teach when learning binary and programming, and it works nicely with a microcontroller.

Would love to see them flying off the shelves at ThinkGeek or somewhere in a snazzy plastic case with an LED matrix instead of just the LEDs. Then you could display other messages too or make selecting the operations graphical.

this is great for schools, to show the kids how binary operations work :)

Nice