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” →

Simple Servo Bot Plans

November 22, 2008 by Eliot 6 Comments

had_arduino_servo

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” →

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.

Case Prototyping

November 16, 2008 by Eliot 11 Comments

[youtube=http://www.youtube.com/watch?v=KsqNPXCm3jc]

[Deviant Ollam], lockpicker and beverage cooling contest host, was recently in Vienna, presumably for DeepSec. While there, he stopped by the Metalab hackerspace and checked out their RepRap rapid prototyping machine. You can see video of his visit above. He had them construct a custom fitted cover for the flash of his point and shoot camera. That’s what we love about rapid prototyping. Many of the projects we cover here solve a particular problem, but would never be considered commercially viable enough to put into production. With the availability of rapid prototyping increasing, hackers can start moving toward producing even more complex objects specific to their needs with a finish closer to commercial products.

Working With High Quality YouTube Videos

November 13, 2008 by Kimberly Lau 22 Comments

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

[Kottke] posted advice for watching and sharing high quality YouTube videos. While it’s not HD quality, it’s much, much better than the normal, fuzzy quality you get on most videos. This hack has been available for some time, but it hasn’t been documented very well until now. When you’re logged in, you can just set the default to “Always play higher-quality video when it’s available”. When you’re linking to a video, add &fmt=18 to the YouTube URL. This also works when you’re embedding the link in WordPress. If you’re not in WordPress, then tack &ap=%2526fmt%3D18 onto each URL in the embeddable code. It’s pretty simple, and makes wasting your day at work much more enjoyable.

Björk Teaches You About Electronics

October 20, 2008 by Eliot 89 Comments

[youtube=http://www.youtube.com/watch?v=75WFTHpOw8Y]

As we often suspected, [Björk] is quite the technical mastermind. In the video above, she teaches you about the ins and outs of her television. We think she’s making a strong bid as the next person to join Prototype This! Her hacking philosophy is the same as ours: “You shouldn’t let poets lie to you.”

XKCD Inspires YouTube Feature

October 9, 2008 by Kimberly Lau 12 Comments

Who knew that a silly comic strip could be so influential? XKCD’s strip focusing on the inanity of YouTube comments inspired someone to actually add the Audio Preview feature to YouTube. It’s provided us with much amusement, especially where one commenter mentions that the “preview of my own post sounded moronic!”

Speech synthesis software is nothing new, of course. While it’s not the most sophisticated software, it’s an invaluable resource to those with disabilities, language learners, and others. This tutorial on Festival, a Linux-based text-to-speech software framework, would be a great place to start. You’re just moments away from finding out how stupid email, IM, and IRC sound read aloud.