Upgrading The Battery In A Wrist PDA

September 8, 2014 by 22 Comments

No, your eyes do not deceive you. That’s a wrist-mounted PDA. Specifically, a Fossil Wrist PDA, also known as an Abacus, that was sold from 2003 to about 2005. Yep, it’s running PalmOS. [mclien] has had this watch/PDA for a while now, and found the original 180mAh battery wasn’t cutting it anymore. He made a little modification to the watch to get a 650mAh battery in this PDA by molding a new back for it.

The original PDA used a round Lithium cell, but being ten years old, the battery technology in this smart watch is showing its years. [mclien] found two batteries (380mAh and 270mAh) that fit almost perfectly inside the battery.

The new batteries were about 3mm too thick for the existing case back, so [mclien] began by taking the old case, adding a few bits of aluminum and resin, and making a positive for a mold. Two or three layers of glass twill cloth were used to form the mold, resined up, and vacuum bagged.

After many, many attempts, [mclien] just about has the case back for this old smartwatch complete. The project build logs are actually a great read, showing exactly what doesn’t work, and are a great example of using hackaday.io as a build log, instead of just project presentation.

1991

September 8, 2014 by 163 Comments

‘We need to move the datacentre to New York by next weekend’

We silently groaned and started working. There were purchases to be made and eventually someone would have to fly out with the tapes.

‘No, we’re not purchasing new equipment. We’re moving the datacentre.’

Ten days. Ten days of crawling under the floor, pulling cables, unbolting, unracking, stuffing U-Hauls to the brim, driving 800 miles, and reversing the whole process. None of us had showered in a week.

When we arrived, there was power. Not much else. We had 63 hours until everything needed to be up. We started stripping RG-58. One guy was wearing this shirt. He was faster.

 

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kegerator

End Table Kegerator Hides The Tap When You’re Not Looking

September 8, 2014 by 31 Comments

What’s better than an ordinary end table? How about an end table that can serve you beer? [Sam] had this exact idea and used his skills to make it a reality. The first step of the build was to acquire an end table that was big enough to hold all of the components for a functional kegerator. This proved to be a bit tricky, but [Sam] got lucky and scored a proper end table from a garage sale for only $5.00.

Next, [Sam] used bathroom sealant to seal up all of the cracks in the end table. This step is important to keep the inside cold. Good insulation will keep the beer colder, while using less electricity. Next, a hole was cut into the top of the table for the draft tower.

The draft tower is mounted to a couple of drawer slides. This allows the tower to raise up and down, keeping it out of sight when you don’t want it. The tower raises and lowers using a simple pulley system. A thin, high strength rope is attached to the tower. The other end is attached to a spool and a small motor. The motor can wind or unwind the spool in order to raise and lower the tower.

The table houses an Arduino, which controls the motor via a homemade H bridge. The Arduino is hooked up to a temperature sensor and a small LCD screen. This way, the users can see how cold their beer will be before they drink it.

To actually keep the beer cold, [Sam] ripped apart a mini fridge. He moved the compressor and condenser coils to the new table. He had to bend the coils to fit, taking care not to kink them. Finally he threw in the small keg, co2 tank and regulator. The final product is a livingroom gem that provides beer on demand.

Demo video (which is going the wrong way) can be found after the break.

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THP Semifinalist: Stubby, The Adorable Hexapod

September 8, 2014 by 18 Comments

After talking with a few of the judges for The Hackaday Prize, documentation will be a large factor in determining who wins and takes a trip to space, and who is left with their feet safely planted on the ground. Stubby the Hexapod is one of the most well documented projects in the running. There are already two hardware revisions for the walking mechanism, several board layouts for the controller, and more project log entries than you can shake a stick at.

Stubby is the brainchild of [The Big One] (a.k.a. [Wyatt] with [Warren], [Princess Sparkle], and [exot] filling out the rest of the team). The project originally began as an educational robotics project meant for teaching [Wyatt]’s kids the ins and outs of robotics and electronics. He’s doing this by developing an open source hexapod robot platform, complete with a frame, electronics board, and a lot of interesting code driving 18 hobby servos.

The frame for Stubby’s first hardware revision is rather interesting; it’s able to be reproduced with nothing more than a scroll saw. The latest revision is a complete rethinking of hexapod locomotion using 2DOF legs and a more mechanical gait.

Being completely open source and very well documented, you can already make your own Stubby hexapod with a scroll saw and the files on [Wyatt]’s site. If 3D printing is more your thing, there’s also a few files to help you with that.

You can check out a few videos of the different Stubby revisions below:

SpaceWrencherThe project featured in this post is a semifinalist in The Hackaday Prize.

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Tracking Footballs With Magnetic Fields

September 8, 2014 by 33 Comments

Official NFL footballs are crafted by hand by a company in Chicago called Wilson Sporting Goods. The footballs that are made there typically range from 11 to 11.5 inches in length and weigh anywhere between 14 and 15 ounces on average. Originally, animal bladders lined the outside, occasionally from the inside of a pig, giving the traditional American football the long-standing nickname of a “pigskin.” Now a days, they consist of cowhide leather or vulcanized rubber with laces that are stitched to the top adding mass. This causes the oblong spheres to be naturally lopsided. This is fixed by inserting extra weight to the opposite side of the football balancing it out. Knowing this, a clever hacker will realize that the balancing spot is a perfect place to subtly add a motion tracking transmitter like this one. Doing so makes it possible to the track not only the position of the ball on the field, but its precise location in 3D space!

Since each football is unique, variations between one ball to another exist. This means that embedding a circuit into a football only modifies the equipment slightly, which is a good thing because sports fanatics tend to be very opinionated about whether or not technology should influence the game. So long as the transmitter and loop antenna added to the air bladder doesn’t pass that threshold of about an ounce (or so) difference in weight, then the football itself really isn’t affected much.

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Infrared-controlled Light Switch

September 7, 2014 by 9 Comments

If you’re looking for your first electronics project, or a project to get someone else started in electronics, [Vadim] has you covered. Back when he was first starting out in electronics he built this infrared-controlled light switch that works with a standard TV remote control.

[Vadim]’s first few projects ended up as parts for other projects after they were built, so he wanted to build something useful that wouldn’t ultimately end up back in the parts drawer. The other requirements for the project were to use a microcontroller and to keep it simple. [Vadim] chose an ATtiny2313 to handle the RC-5 IR protocol and switch the light.

The circuit still has a switch to manually control the lights, preserving the original functionality of the light switch. The rest of the design includes a header for programming the board and another header for tying into the high voltage lines. This is a great project for anyone who knows what they’re doing with mains power but is just getting started with microcontrollers. If properly designed and implemented you’ll never stumble across a room to turn the lights out again!

Perhaps mixing high and low voltages on the same circuit board doesn’t spark your fancy or you can’t modify the light switch in your place of residence? Check out this mechanically-switched light switch.

 

Let The Bass Cannon Kick It!!

September 7, 2014 by 51 Comments

If you’ve ever found yourself immersed in the wild realm of electronic dance music, then chances are you’ve probably heard [Flux Pavilion]’s dubstep banger ‘Bass Cannon.’ The music video released for the track shows [Flux] and his minion [Doctor P] performing twisted audio experiments on unexpecting research candidates by blasting them in the face with strong waves of sound vibrations, which blew back the hair of the people strapped to the chair. The audio trials took place inside what looks to be a warehouse filled to the brim with speakers, heavy duty subs, and sound boards; making it more like a ‘room of bass’ rather than a bass cannon itself. Yet, it inspired one of Hackaday’s Alum to literally create a bass cannon himself. And as you can see in the video below, his device packs quite a punch.

Most of us know [Adam Munich] as the guy who built this portable x-ray machine that could look through just about anything. He’s also built a nuclear bomb detector and has documented several radiation safety techniques, but every once in a while he decides to make something utterly ridiculous like this! He describes his homemade bass cannon as having a variety of fun and exciting uses including a mobile party on one’s shoulders, a way to frizz your hair, or an electrifying method to scare the neighbors.

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