[linux-dude] always wanted to have a binary clock, but he didn’t want to pay someone else to make it for him. Additionally, he was looking for a compact alarm clock he could take on the road, rather than relying on the one in his hotel room.
Inspired by other binary clock projects he has seen over the years, he set off to build his own, which he wanted to fit inside an Altoids tin. His binary clock uses an Arduino Duemilanove (which fits perfectly in the tin) to keep time and control the indicator LEDs. The LEDs are arranged in two rows as you would expect, representing hours and minutes. A small piezo speaker serves as the alarm buzzer, which should be sufficient to wake up most people, though something bigger might be required for heavy sleepers.
We didn’t see any sort of battery pack or power plug mentioned, so we’re not quite sure how [linux-dude] keeps his clock juiced up. Additionally, the lack of an real time clock is something we’re puzzled by. While the Arduino does have a clock function that can be used, an RTC might serve him better – then again if he’s gone for just a day or two at a time, a small amount of drift may not be an issue.