Cheap XY Table Using Hobby Servos

September 30, 2008 by Caleb Kraft 6 Comments

[CarlS] wanted to build a low cost x y table for display on teletoyland.com. He realized that to keep cost low, he could use hobby servos instead of stepper motors. Exact precision wasn’t a big issue here, so the hobby servos would be perfectly acceptable.

Though Linear hobby servos are available, he decided that the cost was prohibitive. He used normal hobby servos, but had to modify their internals to get the exact amount of travel necessary. Many people modify the hobby servos for continuous rotation, but this would cause a loss in the ability for exact positioning. Instead, he replaced the potentiometer that measures the position of the servo with a 10 turn potentiometer. This allowed him 10x the travel.

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Parts: 0.1uF Decoupling Capacitors

September 29, 2008 by Ian 30 Comments

Most ICs need to be decoupled from their power supply, usually with a 0.1uF capacitor between each power pin and ground. Decoupling is usually used to remove noise and to smooth power fluctuations. Every project will need a few decoupling capacitors; our mini web server project has three ICs that require a total of 11. This can be an expensive part to buy in singles, so it’s crucial to stock up online. Read more about our favorite bulk through-hole and surface mount decoupling capacitors after the break. Continue reading “Parts: 0.1uF Decoupling Capacitors” →

The Pinnacle Of Modern Robotics: Bar2D2

September 29, 2008 by Caleb Kraft 8 Comments

[Jamie Price] directed us to this photostream of the build for Bar2D2. Though it isn’t the first bartender bot we’ve covered. It very well could be the best executed. Bar2D2 can travel around the party dispensing bottles of beer, shots, and even cans. The construction looks fantastic. You can follow along in the photostream from the very beginning. It is currently radio controlled and can party for about 8 hours per charge. The next planned upgrade is a system that allows you to choose a mixed drink from a database and Bar2D2 will mix it up.

As you can see from the pictures, Bar2D2 is the life of the party, attracting pretty girls and cheesy sci-fi tv pirate astronauts too.

Peltier-based Cooling/heating Backpack

September 27, 2008 by Nick Caiello 16 Comments

[Max Weisel] recently created a Peltier-based cooling/heating system that fits into a backpack. The system uses two Peltier units, each running at 91.2 watts, with computer heat sinks mounted on one side of the unit to dissipate the excessive amounts of heat generated. While he was originally trying to build a cooling backpack, the use of the Peltier units meant that the cool side would become warm when the direction of current was switched, meaning that the backpack could become a heating backpack with the flip of a switch. In order to power the two Peltier units, he uses two 12v motorcycle batteries, weighing in at around 5 pounds each. While this backpack might be a little heavy for your back, it looks promising for anyone who needs to keep things cool (or warm) on the go.

Knit Touchpad

September 26, 2008 by Caleb Kraft 9 Comments

[Plusea] made her own touchpad using some anti-static gloves and an Arduino. This proof of concept is fairly small, but the system could be scaled quite large if you could find the fabric. She cut apart the anti-static glove, mounted it and wired it to the Arduino. A special piece is made to fit over the finger that is also wired to the Arduino. The location of where she touches is determined by the resistance between the finger and each corner. Watch the video on the instructable to see how it measures.

She mentions that there are a few different ways to build it, some which would not require anything on your finger, but would use another piece mounted behind the touchpad. The method she is currently using though, would allow for the fabrick to be any size or shape, even molded around something.

How-To: Web Server On A Business Card (Part 2)

September 25, 2008 by Ian 140 Comments

This mini web server is slightly smaller than a business card. There are a lot of tiny one-board servers out there, but this is probably the smallest you can etch and solder at home. Unlike many embedded web servers, files are stored on a PC-readable SD card, not in a difficult-to-write EEPROM. Read on for the web server design, or catch up on PIC 24F basics in the previous article: Web server on a business card (part 1).

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Arcade Button Monome: Moanonme

September 25, 2008 by Caleb Kraft 12 Comments

[Johan Larsby] built this pretty cool Monome clone. He was starting with a kit to build an Arduinome, but had issues getting his LED matrix to work correctly. After digging around in some old parts and hacking together some custom LED arcade buttons, he ended up with the Moanonme. Be sure to check out the video after the break.

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