Tug Of War… With Your Mind, Man!

July 8, 2012 by 17 Comments

Challenge your friends to a little mental Tug of War thanks to the Omaha Maker Group’s Red Bull Creation contest entry. The power struggle is all in your mind, and can only be won if you’re able to concentrate deeply and quickly. The headsets worn by each competitor monitor brain waves over a ten second window. If you concentrate more deeply than your opponent they’ll get a squirt of water in the face. If no one is concentrating well the contest is a draw the measurements start again. The screenshot above was taken from the test footage found after the break.

Hardware details are scant on this one. Obviously the Bullduino is the centerpiece of the build, taking readings from the headsets. A motor moves the water nozzle along a slit cut in the top of the sphere.  Progress during the 10-second window is displayed by that nozzle, which starts in the center yellow ‘safe’ zone and moves to one side or another to enter the green ‘kill’ zone.

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Adding An Auto-shutoff To The Simplest Of Drip Coffee Makers

July 8, 2012 by 15 Comments

[Jerry Pommer] and his wife have relied on a percolating coffee pot for years. We have fond memories of camping trips with these things; they make great coffee which tastes even better on a cold morning in the back woods. But a recent package from the stork means that they no longer have time to sit and watch the coffee perk. After several days of boil-overs [Jerry] switched to this very basic drip coffee maker he salvaged from the trash pile. It has one switch that turns it on and off and nothing else. In order to make sure he doesn’t forget to turn it off, he hacked together his own shut-off timer for the device.

His write-up is all back story, but the 34 minute video embedded after the break takes us through the hack itself. We like it that he starts by discussing the different options that he could have chosen. Of course it might have been a microcontroller, or a 555 timer keeping time. But in the end he went with a simple resistor-capacitor timer. The carefully calculated component pair drives a Darlington transistor which keeps a relay closed. When the slowly draining capacitor lets the voltage drop past a certain threshold it also kills the power to the hot plate. In this case it will only stay on for about a half hour.

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Another Switch Mode Regulator Swap For The Raspberry Pi

July 7, 2012 by 32 Comments

[Karl Lunt] is working to slim the Raspberry Pi current draw as much as possible. The first step in his journey was to replace the linear voltage regulator with this switch mode version. It’s a step-down voltage regulator circuit with a tiny footprint and a matching price tag (about $10) made by Pololu. It’s small enough to be mounted in the empty space between the LCD ribbon connector and the main processor.

The project was based on the hack we saw at the end of June. But we give much more credit to [Karl] for removing the old part in a safer way. He clipped the two small leads on the bottom of the old part, then used a beefy iron to sufficiently heat the large pad before removing the body of it. With the old part out of the way it’s just a matter of connecting the three wires in the right configuration.

This cut consumption by about 50 mA. He’s hoping to do more by removing the on-board LEDs. His goal is a draw of under 250 mA in order to make it last a reasonable amount of time when running from batteries.

All-terrain Electric Scooter Build

July 7, 2012 by 18 Comments

This all-terrain electric scooter can destroy the speed limit in a school zone without even trying. [Ben Katz] built from the ground-up and did an amazing job of documenting the journey.

He strated by redesigning the suspension of a plain old kick-scooter to use these large inflatable wheels. This includes a suspension system that helps cushion the rider from the bumps of an uneven driving surface. The increased deck height leaves plenty of room for the locomotive parts. You can see the three cylinders mounted near the rear wheel. Those are the motors, connected to a single drive shaft with a gear box which [Ben] built. The drive shaft powers the rear wheel via chain drive. Batteries are housed in the rectangular enclosure in front of the motors.

Don’t miss the video after the break. [Ben] takes the thing on and off-road, averaging 15 MPH while topping out at 24!

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Resurrecting A Hi-Fi Cabinet

July 7, 2012 by 25 Comments

[VintagePC] pulled this old stereo out of a barn. It was in pretty shabby shape, but he managed get it running again and make it look great as well.

While it had been protected from the elements, it had not been protected from the rodents. Mice had chewed their way through the fiberboard backing and made a nice home inside. He mentions that they chewed the string which operates the tuning dial, and we’re sure they were the cause of other problems as well. He gives the wise advice of not powering on an old set like this until you have a chance to assess the situation.

The insides of the amplifier were about as disorderly as the last radio repair we looked at. But after carefully working his way through the circuits, replacing capacitors and resistors as needed, he started to make some progress. The receiver coil needed to be rewound and he used wire from an old CRT monitor for this purpose. The loop antenna was remounted and the record player arm was given a new cartridge and balanced using a clever LEGO apparatus. Some veneer work and wood finishing brought the case itself back to its original beauty. We’d say the hard work was well worth it. He’s got a big piece of furniture he can always be proud of!

Going To The Park With Your Augmented Reality Girlfriend

July 7, 2012 by 50 Comments

Lonely? Bored? Really into J-pop? If you’re any of these things, here’s the build for you. It’s an augmented reality system that allows you to go on a date with one of Japan’s most popular virtual singers.

The character chosen to show off this augmented reality girlfriend tech is [Hatsune Miku], a voice synthesizer personified as a doll-eyed anime  avatar. [Miku] is an immensely popular character in Japan, with thousands of people going to her concerts, so choosing her for this augmented reality girlfriend project was an obvious choice.

The build details for this hack are a little sparse, confounded by the horrible Google Translate results of the blog linked in the YouTube description. From what we can gather from the video and this twitter account, the build is based on an ASUS Xtion Kinect clone and a nice pair of video goggles.

We’re expecting the comments for this post to fill up with, ‘Japan is really weird’ comments, but we can see a few very, very cool applications of this tech. For instance, think how cool it would be to be guided around a science museum by [Einstein], or around Philadelphia by [Ben Franklin].

Monitoring A Clothes Washer With An Accelerometer

July 7, 2012 by 15 Comments

[Viktor’s] washing machine did a good job of cleaning his clothes, but it kept a bit too quiet about it. The machine doesn’t have an audible alert to let him know the cycle has finished. He decided to build his own alarm which can just be slapped on the side of the machine.

You can see that a couple of magnets hold the board to the metal housing of the washer. The board doesn’t actually connect to any of the machine’s circuitry so this should work about equally as well for any unit. The detection is based on motion, thanks to a Freescale MMA7361 3-axis accelerometer. When he starts a load of wash he flips the power switch for the board on. The PIC 12F683 that drives the device starts monitoring the accelerometer for changes. If it goes for more than about one minute without reading motion the piezo buzzer starts beeping. It’s a fun and easy solution along the same line of this oven pre-heat alarm add-on.