NeatTrix

If you are like me, then you have about 137 wall warts and no way to plug them in. Newer wall warts tend to be more “outlet-friendly”, but many still will not allow use of adjacent outlets when plugged in. Grrrr!

To help solve this dilemma I buy short power cords to move the wall warts off the strip. Maybe you already do this. A good, reasonably inexpensive source for these is Jameco (about $2.50). They also sell a twofer cable for about $6.50.

www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=199778&

www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?jameco_page=42&langId=-1&productId=208347&catalogId=10001&freeText=208347&storeId=10001&search_type=all&ddkey=http:StoreCatalogDrillDownView

Since the new Kindle will soon take the place of the current model, I thought I’d give a nod to Igor Skochinsky, who notoriously hacked the Kindle over a year ago.  In an interview, he described the Kindle as a closed system, but not that closed.  He also said the Sony Reader and iPhone were much more closed.  Easy or not, here are the three entries from his blog, detailing the steps taken to gain access to the console, and mess about inside. (continue reading…)

Well, the JB Weld epoxy held for a month, and then gave up. I was really disappointed. I mean, it really did the trick…until it didn’t. The inside of my shower and car should be covered with the same substance as Amazon has coating the access cover of the Kindle. They might be a lot easier to keep clean then, as nothing much seems to stick to the stuff. What’s even more vexing is that the epoxy directly in contact with the cover material didn’t fully set. I saw the reverse situation in another project where silicone sealant covering an epoxy repair never fully cured. Curious.

Anyway, I was back to square one. I really, really  liked the Velcro straps for the Kindle, and I’m not one to just give up.
(continue reading…)

I found this a few years ago and I bookmarked it thinking this would be something I’d like to make. Well, I still haven’t gotten around to make the thing, but for some reason it always survives my bookmark purges.  The fear is you have a system crash and your cat starves to death, or at very least eats the other cat.

http://www.leeholmes.com/blog/DIYCatFeederAndWaterDispenser.aspx to see more details about the feeder.

We do a lot of hand assembly for prototyping (playing), and some small-volume production. With sufficient magnification, good light, a decent soldering iron, a steady hand, and practice, it’s really not that hard. The key is having the right tools. Good desoldering braid is essential.  For me, only Soder-Wick will do. Others just don’t seem to work as well.

I’ll get to other tools later. What I spent a long time working out was finding a good surface for assembly of PCBs (printed circuit boards) with lots of surface mount components. I wanted something that had some “grip” to it, something that would keep those tiny parts and the PCB from sliding around too much. Often you have to orient or flip a resistor or other component. This usually has to be done one-handed with tweezers.  The surface I was looking for would help with that. The surface could not be too “bouncy”, though. It needed to be resistant to a soldering iron. The surface should not accumulate a static charge. It’s also a boon to be able to easily change the angle of the board you’re working on without picking it up.

It was easy to fulfill that last requirement with a lazy susan turntable. Rubbermaid makes an inexpensive one. The one shown is sold at ACE Hardware for less than $5.00. The surface melts and chars un contact with a hot soldering iron. That’s not desirable. I had some two-part urethane potting compound from Loctite. The turntable has a lip. I was able to pour a new, flat urethane surface on the turntable. Not bad. The urethane was resistant to hot soldering iron and had most of the other characteristics I was looking for. The problem was that I had to buy the urethane by the quart, and it was not cheap. I had purchased the urethane for another project, and the leftovers just came in handy.

I was still in search of a more practical solution. And then I stumbled across this at (of all places) Joann Fabrics. It’s one of the few times I was glad to have been dragged along on one of my wife’s hunting expeditions.

The glue gun pad is inexpensive (around $6; www.joann.com/joann/catalog.jsp?CATID=cat2902&start=17). It does not melt in contact with the hot soldering iron and the surface has almost the ideal “grip”.  The surface washes easily, and resists most solvents and adhesives. Put one on top of the lazy susan, and it makes assembling PCBs with lots of surface mount components much easier. I prefer the clear variety. A similar, gray-colored pad is available at hotstik.com/store/pc/Non-Stick-Glue-Pad-11p59.htm for $4.75.  Both pads are 8″ x 8″ and fit well on the turntable. Cut the corners on the pad to inscribe the mat inside the circle of the turntable (optional). The only thing missing now is some sort of foot operated brake system for the turntable so that it will only rotate when I want it to. Mount through-hole components last so that the board sits flat on the mat while you’re soldering on the surface mount components.

Other good things to have for surface mount assembly:

Magnification aids (all rather inexpensive):

www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=98722 and www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=47995.

www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=96358

www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=95043

www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=95890

Anti-static, really fine tweezers like these (from Digi-Key) are really good to have. In fact, you probably can’t have too many of tweezers of various sizes and shapes. Another tool of choice are ratcheting forceps (hemostats) with very small jaws. Vacuum pickup pens can be useful mainly for ICs.

Johnny Chung Lee has been doing some neat stuff. Admittedly, I saw these videos last year. I thought Mr. Lee had great potential then, and now he’s working for Microsoft. Maybe there’s hope for Microsoft. His main site is www.cs.cmu.edu/~johnny/. The Wii remote stuff is located at www.cs.cmu.edu/~johnny/projects/wii/.

Anyway, these videos are great examples of coloring outside the lines.

There are ways to do the some of the same tricks with a webcam, but you can’t beat this Wii remote as a platform. For $40 you get an IR-sensitive camera, 3-axis accelerometer, lots of buttons, and a Bluetooth connection to a computer. The Wii remote uses the ADXL330 3-axis accelerometer from Analog Devices. The sensor bar referred to in the videos is several IR (infrared) LEDs (light-emitting diodes) with a known spacing. There are 5 LEDs located at each end of the sensor bar. The apparent spacing of the LEDs in combination with the accelerometer data (tilt and velocity) yields positioning.

If only the Emotiv Headset had some IR LEDs…

NOTE:  There has been an update to this article. Click here for the most recent developments.

The Amazon Kindle is an electronic book reader with an electronic-paper display and an EVDO wireless network connection (no extra cost). More than 200,000 titles are available, most for less than $10. Some books are free (you get what you pay for). Overall, I’ve been very happy with the Kindle, and have read more than 75 books using it.

Both my wife and I have Kindles. Both are registered in my name. Once purchased, we can both download a title and read the same book at the same time. I suggest that book clubs considering using the Kindle purchase and register all the Kindles for the group together.

There are a few things I don’t like. The ridiculously large “Next Page” button, and the smaller (but equally annoying) “Back” button on the right side of the Kindle cause endless frustration when accidentally touched. I had considered several options including hammers, nails, and superglue) before trying the solution below. It really works well. Better yet, it’s easily undone.

The second problem was holding the Kindle comfortably. The folder/book cover/piece-of-crap Amazon included with the Kindle is fine for protecting the Kindle while transporting the Kindle, but doesn’t help me hold the Kindle comfortably while reading. The Kindle is very light, lighter than some paperbacks, and certainly lighter than most hardcover books. I tried a couple of things and settled on the solution shown below.

The access cover on the back of the Kindle slides out to gain access to the battery, SD memory slot, and some sort of programming connector hidden under another access door. This access cover (door)  is coated with some sort of soft, rubbery compound that improves your grip. Sadly, not enough. Also, the coating doesn’t bond to many adhesives.

The first attempt was to just put some large rubber bands around the access cover and snap the access cover back in place. Not only didn’t the cover sit quite flat afterward, but the rubber bands were too tight.

The second attempt was to use some self-adhesive, industrial-strength Velcro on the access cover. This is shown in several of the photos below (for example, button6). The “hook” side of the Velcro was  attached to the Kindle. Two loops were fashioned from Velcro One-Wrap. These loops were positioned so that I could put my hand through both loops to hold the Kindle. Thanks to the Velcro, I could reposition the loops on the Kindle, as well as the size of the loops.

I purchased the self-adhesive Velcro from Lowe’s.

This worked fairly well, but the self-adhesive Velcro kept pulling off the access cover because of the poor adhesion to the rubbery coating. Also, I had started with the hooks, so the interior of the loops (straps) made from the One-Wrap  was also of the hook variety. This was sort of rough on the hands.

The final attempt is more permanent. I glued strips of the Velcro One-Wrap (also purchased at Lowe’s) to the Kindle’s access cover with some J-B Weld epoxy I purchased at True Value Hardware . This epoxy is also available at K-mart, Wal-Mart, Home Depot, and PepBoys. This epoxy mixes up to a gray color similar to the color of the outside of the access door. It takes almost 24 hours to fully set though.

Even though the strips of Velcro are glued in place, the access cover is still removable. Take off the straps, and the Kindle still fits in its book cover (not that I use it).

Button1: The Kindle at left. A full cable tie is shown next to the Kindle. Shorten the cable tie at both ends to the length of both buttons. This can be done by eye with some scissors.

Button2: Insert the cut cable tie under the edge if the “Next Page” button, starting at the top. The Kindle is sitting on a roll of Velcro One-Wrap.

Button3: Continue inserting the cut cable tie until the cable tie extends under the leading edge of both the “Next Page” and “Back” buttons.

Button4: Another view showing how the cable tie runs under the button.

Button5: After the cable tie is fully inserted, it shows along the top of the “Next Page” button the right side of the Kindle. This makes it easy to pull the stop out if you need to.

Button6: The bottom of the Kindle showing the fully-inserted cut cable tie. This completely inhibits these two buttons. Cut the cable tie even shorter and only place it under the “Next Page” button to retain operation of the “Back” button. Also shown the self-adhesive, industrial-strength Velcro applied to the Kindle’s access cover. I rejected this Velcro method afterward.

Strap1:  This shot shows the roll of Velcro One-Wrap, a cut cable tie for button inhibition, and a portion of my Kindle with its first application of self-adhesive Velcro.

Strap2: This is the original strap solution. Self-adhesive, industrial-strength Velcro hooks are affixed to the Kindle’s access door. Straps are made from two lengths of the Velcro One-Wrap. One-Wrap has hooks on one side and loops on the other. This stuff is terrific! This solution worked for a couple of weeks, but, sadly, the self-adhesive Velcro kept pulling loose.

Strap3: Original strap system from another angle.

Strap4: Revised strap system. After removing the white Velcro hooks, I used epoxy to glue strips of Velcro One-Wrap on the Kindle’s access cover. The loop side is up this time.

Strap5: Revised system with one strap. The strap now has the loop side inside.

Strap6: Kindle with two straps.

Strap7: Strapped Kindle from another angle.

Strap8: Ditto.

Strap 9-14: Photos of my meaty mitt holding the newly strapped Kindle at various angles. Your Velcro One-Wrap mileage may vary.