Tennis Ball Fetcher

November 22, 2008 by Eliot 2 Comments

tennisball

Reader [Julian von Mendel] and his team built this tennis ball fetching robot for a competition (translated). The first version used distance sensors to locate the tennis balls for pick-up, but they changed to a camera based approach. The robot has three omniwheels and is designed to calculate the shortest path to the ball despite orientation since it can rotate while traveling. The wheels are monitored using rotation sensors from PS/2 mice. The control is provided by 3 Atmel microcontrollers that communicate via SPI. The multiprocessor design is fairly generic and could be reused for a different style of robot. While their robot performed fairly well, there were some shortcomings. The limited storage space meant frequent trips to drop off balls. The tilting bucket kept them from picking up tennis balls that were against the wall. Also, the bot had to be disassembled for battery swaps. The project is very well documented and they’ve released all of their control code. You can see the robot retrieving a ball after the break. Continue reading “Tennis Ball Fetcher” →

CCFL Bike Wheel Lights

November 22, 2008 by Eliot 14 Comments

ccfl

We’d never discount the beauty that is the SpokePOV bike wheel kits, but if you want to just turn your bicycle into a blinding blur, [depotdevoid] has the solution for you. He had a CCFL tube left over from an abandoned LCD monitor backlight repair, and decided to see what it would look like as a wheel light. The result turned out fairly well. He had to figure out how to mount the 8 batteries plus step-up board. He says the extra weight isn’t really noticeable and the light output is quite bright. CCFLs can be incredibly fragile, so take care when you do the actual mounting.

Cythbot, Pneumatic Guitar Hero

November 22, 2008 by Eliot 7 Comments

cythbot

Here’s yet another robot hoping to dominate the human race through the power of ROCK. Cythbot was built to demonstrate Cyth Systems machine vision systems. The device uses a camera to watch the Guitar Hero monitor and identify notes for button presses. The strum bar is then triggered after a delay. The notes are identified solely by pixel intensity since star power can cause them to change shape and color. All button presses are done using pneumatics. The whole system is self-contained and doesn’t require a separate computer for processing. Our favorite part is that the controller remains completely unmodified and the industrial light tree used to indicate notes. The team says that the pneumatics aren’t quite fast enough to hit 100%, unlike some humans. Video of the bot in action after the break. Continue reading “Cythbot, Pneumatic Guitar Hero” →

Simple Servo Bot Plans

November 22, 2008 by Eliot 6 Comments

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oomlout has posted some interesting plans for a simple robot. It’s based around an Arduino and is a platform similar to the Parallax Boe-Bot. The Arduino sends PWM signals to continuos rotation servos that drive the two main wheels. All of the structural components are laser cut from acrylic with slots to hold standard hex nuts. It’s an interesting technique, but the design has a lot of potential for improvement. Right now it uses two different power supplies and a breadboard for simple connections. From the video below, you can see that the balance could be improved as well. Continue reading “Simple Servo Bot Plans” →

Johnny Lee’s Favorite Wiimote Projects

November 21, 2008 by Eliot 4 Comments

[youtube=http://www.youtube.com/watch?v=txtl51YDMYw&fmt=18]

There is no doubt that [Johnny Lee] is the authority on Wiimote based projects. So, when he compiles a list of his favorite Wiimote projects, we definitely pay attention. He’s organized the list as a progression of the unusual. By the time you get to ‘Chicken Head Tracking‘ at the bottom, you’ll be adequately prepared. You’re bound to get some inspiration from the list even it’s building a pigeon guided missile.

CNC Engraver Upgrades

November 21, 2008 by Eliot 3 Comments

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We’ve been following [glaciawanderer]’s CNC build for quite some time and he’s recently added a few upgrades to make for an even more interesting machine. He’s been trying out new bearing blocks, anti-backlash nuts, and z-axis plates hoping to get some improvements. In the case of the bearing blocks, he went back to the older style because of the added safety and smoother movement. The final addition he made was a dust collection system. It’s just a couple support hoops and duct tape, but it should keep dust out of the threads and rails.

YouTube Testing Even Higher Quality Videos

November 21, 2008 by Eliot 27 Comments

[youtube=http://www.youtube.com/watch?v=zlfKdbWwruY&fmt=22]

YouTube, purveyor of some of worst looking flash video is finally getting their act together. We posted the other day about embedding videos using &fmt=18 to get higher quality YouTube videos. It seems the awesome knob has now been turned up to &fmt=22. All of the previous tricks should work, just use 22 instead of 18. This all depends on the highdef version being available. Now they just need to get rid of the grainy preview images.