Tic-tac-toe (or “Noughts and Crosses”) is a game simple enough to implement in any computer system: indeed it’s often used in beginner’s programming courses. A more challenging project, and arguably more interesting and useful, is to make some kind of hardware that can play it in real life. [mircemk] built a simple yet elegant machine that can play tic-tac-toe against a human player in a way that looks quite similar to the way humans play against one another: by drawing.
The robot’s design and programming were developed at PlayRobotics, who named the project TICO. The mechanical parts are available as STL files, to be printed by any 3D printer, and a comprehensive manual explains how to assemble and program the whole thing. Since it’s all open source, anyone can build it from scratch and modify it to their liking. The pictures show the original design by PlayRobotics, while the video (embedded after the break) shows [mircemk]’s version, which includes a wooden frame that gives it a bit more presence.
[td0g]’s AutoWhiteboardBot is not just any 3D printed whiteboard plotter, because it also sports a triple-marker carrier and on-board eraser! The device itself hangs from stepper motors, which take care of moving the plotter across the whiteboard, and the trick to making the three colors work was to incorporate retractable dry-erase markers. A spherical Geneva drive-based assembly on the plotter rotates the pen cartridge, and a plunger activates the chosen color. Erasing, arguably the easiest thing to do on a whiteboard, is done by a piece of felt. 3D printed parts are on Thingiverse and [td0g] says software is coming soon. It’s a clever device, especially the method of accommodating multiple colors with retractable markers.
Wiping a whiteboard can be a tedious chore. Nobody wants to stick around after a long meeting to clean up, and sensitive information is often left broadcast out in the open. Never fear, though – this robot is here to help.
Wipy, as the little device is known, is a robotic cleaner that scoots around to keep whiteboards clear and ready for work. With brains courtesy of an Arduino Uno, it uses an IR line-following sensor to target areas to wipe, rather then wasting time wiping areas that are already clean. It’s also fitted with a time-of-flight sensor for ranging, allowing it to avoid obstacles, or busy humans that are writing on the board.
If Wipy lacks anything, it’s probably discretion. Despite its cute emoji-like face, it’s not really capable of tact, or knowing when it’s not needed. It’s recommended to keep Wipy powered down until you’re completely finished, lest it barge in and start wiping off important calculations before you’re done.
For some of us here at Hackaday, school is but a very distant memory. All that teenage awkwardness we’d rather forget, synth pop, and 8-bit computers were cool the first time around, and our newer classrooms didn’t have blackboards any more. The Whiteboard Future Had Arrived, and it came with solvent-laden pens that our more rebellious classmates swore would get you high if you sniffed them for long enough. Innocent times. Kids nowadays probably get their lessons from iPads, but the whiteboard isn’t finished just yet. [f4hdk] has updated his board with Scribot, a whiteboard-writing robot arm driven by a couple of stepper motors and a nicely-engineered set of belts, that writes text from ASCII files in a custom-designed vector font.
At the end of the arm is a whiteboard marker, and in a neat twist it has an eraser on its rear end. A quick flip of the servo holding the marker, and it can rub out any of its work. Behind it all is an LPC1789 Cortex M3-based Mbed board with appropriate servo driver boards, and for those curious enough to take a second look there is a full code repository. The result as you can see in the video below the break is a very well-executed whiteboard writer. Your 1980s teacher might have grumbled at the new technology, but certainly couldn’t accuse it of doing a bad job!
If you are reading this, it is a fair bet you like to take things apart. Sometimes, you even put them back together. There are two bad moments that can occur when you do this. First, when you get done and there is some stuff left over. That’s usually not good. The other problem is when you are trying to find some little tiny bolt and a washer and you can’t find it. SMD parts are especially easy to lose.
A few months ago, I was browsing through a local store and I saw a neat idea. It was basically a small whiteboard with lines dividing it into cells. It was magnetic and the idea is you’d put your small loose (and ferrous) parts like screws, bolts, nuts, and resistors on the board. Since it was a marker board, you could make notes about what each cell contained. Great idea! But the thing was about $20 and I thought I could do better than that. As you might guess from the picture, I was successful. I spent about $5, although I had some rare-earth magnets hanging around. If you don’t, strong magnets aren’t that expensive and you can often raid them out of hard drives.
[Maurice] recently built a clock that draws the time (Google Doc) on a white board. We’ve seen plenty of clock hacks in the past, and even a very similar one. It’s always fun to see the different creative solutions people can come up with to solve the same problem.
This device runs on a PIC16F1454 microcontroller. The code for the project is available on GitHub. The micro is also connected to a 433MHz receiver. This allows a PC to keep track of the time, instead of having to include a real-time clock in the circuit. The USB connector is only used for power. All of the mounting pieces were designed in OpenSCAD and printed on a 3D printer. Two servos control the drawing arms. A third servo can raise and lower the marker to the whiteboard. This also has the added benefit of being able to place the marker tip inside of an eraser head. That way the same two servos can also erase the writing.
The communication protocol for this systems is interesting. The transmitter shows up on [Maurice’s] PC as a modem. All he needs to do to update the time is “echo 12:00 > /dev/whiteboard”. In this case, the command is run by a cron job every 5 minutes. This makes it easy to tweak the rate at which the time updates on the whiteboard. All communication is done one-way. The drawing circuit will verify the checksum each time it receives a message. If the check fails, the circuit simply waits for another message. The computer transmits the message multiple times, just in case there is a problem during transmission.
Pinball machines are fascinating pieces of mechanical and electrical engineering, and now [Yair Moshe] and his students at the Israel Institute of Technology has taken the classic game one step further. Using computer vision and a projector, this group of engineers has created an augmented reality pinball game that takes pinball to a whole new level.
Once the laptop, webcam, and projector are set up, a course is drawn on a whiteboard which the computer “sees” to determine the rules of the game. Any course you can imagine can be drawn on the whiteboard too, with an interesting set of rules that no regular pinball game could take advantage of. Most notably, the ball can change size when it hits certain types of objects, which makes for a very interesting and unconventional style of play.
The player uses their hands to control the flippers as well, but not with buttons. The computer watches the position of the player’s hands and flips the flippers when it sees a hand in the right position. [Yair] and his students recently showed this project off at DLD Tel Aviv and even got [Shimon Perez], former President of Israel, to play some pinball at the conference!