Tennis Ball Fetcher

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”

CNC Engraver Upgrades

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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.

Sonar Navigation Jacket

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[Lynne] had this crazy idea to build a piece of clothing that would give you feedback about your surroundings using sonar. She started with a carefully selected thrift store jacket. She wanted something that looked good and also provided plenty of places to hide electronics. She used the LilyPad system, with a vibration pad and a sonar range finder. When the system detects an object within a certain distance directly in front of the wearer, it warns them with some vibration. Not only is it practical, it looks pretty cool too. Did we mention she designs clothing?

She notes, in the comments section, that while it can detect an obstacle, it cannot detect a void. How could she detect a drop in the floor or a step down?

Animated LED Keyboard

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[Brian] made this really cool LED keyboard. He started with a Deck Legend Fire. When he got it, he realized that every key had its own LED, but the entire unit was either on, or off. He just couldn’t live with that and decided to start hacking into it to make each light individually controlled. He found a perfect empty space in the back of the keyboard and designed custom PCBs to control his lighting. he notes that he spent 12 hours of cutting and soldering wires to each of the lights in the keyboard, that doesn’t include the PCB construction.

In the end, he had a fantastic looking keyboard that had cool effects like heat mapping and idle animations. All stock features still work and it looks almost entirely stock. The only obvious difference is the fact that it has two USB cables coming out of it due to some issues with his KVM switch not detecting it.

Full Fabric Soft Switches

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When we created our backpack strap WiFi detector for Engadget, we embedded soft switches to control the device. They used two sheets of aluminum foil separated by a layer of foam with holes punched in it. [Plusea] has taken a similar approach but has replaced the aluminum foil with conductive fabric. The end result is a set of three soft buttons that can be easily washed. Have a look at the video of it in action below. Check out the followup project that uses the buttons to replace a scroll wheel. Continue reading “Full Fabric Soft Switches”

Microcontroller Fireworks Launcher

[vimeo 2245777]

After being inspired by our previous posts on a microcontroller-powered missile launcher and the wireless fireworks controller, [Adam] at Additronics.com decided to build his own microcontroller launcher. He combined elements from each of the prior projects, and included some of the advice from the Hack a Day comments. His multi-rocket/fireworks launcher is configured with an Arduino Diecimila, and requires a whole boatload of batteries. [Adam] claims there’ll be another video at New Year’s of the microcontroller in action, which we’re definitely looking forward to watching.

Mac Pro Ultra Mini

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[Matthew] sent in this slick project where he made a Mac pro Ultra Mini. He received a MacBook that had been killed by water. He took it apart, re-soldered some connections and was able to get enough of it working to be a decent multimedia machine for his tv. To make it look nicer, he found an external drive case that looks like a tiny Mac Pro. After a little bit of grinding, cutting, and zip tying he managed to get all the pieces inside the case.  We’re always happy to see hardware salvaged, and  to see it transformed to a fantastic looking useful machine is a bonus. Good job [Matthew].