Stonehenge uses a CrustCrawler Smart Arm and a Parallax Propeller chip to display the current time. All the digits needed to display the time are located on cards positioned in a semi-circle around the left and right sides of the arm. The time itself is displayed in front of the arm. This gives the clock a “Stonehenge” like appearance. There are a total of 14 cards. Each card has two digits with one on each side. The software planner determines which card and which side is needed to display the time and then sends the necessary movement commands to the arm.
What happens when the robot knocks over one of the cards and can’t pick it up? Does it get stuck on the time or does it just go on to the next card, et cetera? The clock is pretty cool though, in a Rube Goldberg sort of way – a more complex and cool way to do something that’s fairly easy to do. [Norris Labs via BoingBoing]