I made myself one of the paper wallets as shown in the Instructable, but realized after a few days of use that it would not last long in an abrasive jeans pocket, and would be absolutely wrecked at the first sign of moisture. I took a brief survey of the paper items around my room which could be more suitable materials for a wallet, and found that I had some USPS Priority Mail envelopes, which are made of a pretty heavy-duty teflon. Here’s a quick overview of how I put the wallet together using the envelope:

First off, I sliced open the envelope, and measured out an 8.5 x ll” section, being careful to feature some of the USPS labeling on the section that would become the exterior of the wallet:

The next step was to cut out the marked off section, and put the initial folds in it, as directed in the paper wallet Instructable. I then sliced out the card openings on the section that would be the inside of the wallet, using a tin can lid as the template:

Next, it was a simple matter to perform the final Zipper-cuts as directed in the Instructable, and fold the wallet into its final form:

One final touch I decided to add to the wallet was to finish the edges with some reinforcing layers, cut from the adhesive-backed flap of the envelope. I cut appropriately sized sections, and applied them to each end and the bottom of the wallet:

With that, the wallet was finished! I loaded it up and gave it a test run (I’m not normally that rich, but I borrowed some money for the sake of demonstration):

I’ve been using the wallet for about two months now, and it’s holding up really well… way better than the previous one I made out of normal paper. Some of the exterior colored bits are starting to wear through, but I think I should get another solid three or so months out of the wallet before making another one. Not bad for a DIY wallet that cost nothing to make!

I’ve received a ton of compliments on the wallet, with people asking me where I bought it. If I wasn’t sure the USPS would sue me, I’d consider selling them on Etsy or something for a hefty markup, but that seems like a risky proposiiton. Anyway, perhaps this will become a trendy way to repurpose all those Priority Mail envelopes after the USPS goes under.

I made some GoPro cheat sheets that I printed out and then taped to the box where I store the GoPros, so that it’ll always be close at hand when I need it. I’ve even folded up one of the smaller ones and inserted it behind the camera in the waterproof case so it’s easy to get to if I need it on the go.

I’ve posted the cheat sheet I put together here, in case it’s useful to someone else. There’s a pocket sized 4×2″ version (GoPro HD Hero Cheat Sheet 4x2inch), and a larger, easier to read 7×2″ version (GoPro HD Hero Cheat Sheet 7x4inch), both in .pdf format. I’ve also posted the excel file I used to create them (GoPro HD Hero Cheat Sheet Excel File), in case you want to modify them to suit your particular tastes.

Files:

• GoPro HD Hero Cheat Sheet Excel File (57kB .xlsx)
• GoPro HD Hero Cheat Sheet 7x4inch (45kB .pdf)
• GoPro HD Hero Cheat Sheet 4x2inch (49kB .pdf)

A pretty cool article describing some of the up-till-now secret sauce on the electric motorcycle project I’ve been working on with Chip Yates for the last few months. The article describes the front-wheel Kinetic Energy Recovery System that Chip designed in great detail. It has some cool pictures of the bike, and an awesome video that someone (ahem, yours truly) put together for the bike unveiling a few weeks ago.

Now that I’m working and have more dollars than sense and finally have a car that’s big enough to hold a decent audio setup, I finally decided to buckle down and install a woofer. Following is a writeup of my install.I bought my GTI back in May 2009, and I’ve been pretty happy with the stock sound system except for the lack of bass. If I turned up the bass control knob at all, it would just distort and sound horrible. Otherwise, the stock system was pretty clean and loud however. I haven’t been really impressed with any of the aftermarket head unit installs I’ve seen in GTI’s, so I decided to keep the stock head unit and the stock speakers, at least for the time being. After surfing the forums and discussing it with some audio-nut friends, I decided a single 8″ or 10″ sub would likely do for my needs.

The GTI

Because the stock system maxes out at about 20W per channel, I figured I should take it pretty easy with the wattage I put in for my woofer, so as not to overpower the stock system and end up with nothing more than a deafening back massager. After shopping around a little and reading amp reviews, I settled on a JL 250.1 mono amp. I had been wanting to mount the amplifier under my drivers seat since there’s a nice little cutout there, and as it turns out this JL amp is an absolutely perfect fit for the space.

Having selected the amp, I started hunting for subs and enclosures. I contemplated making my own MDF enclosure to fit toward the side of the trunk, but I ran across a beautiful fiberglass enclosure from Audio Integrations that tucks back into one of the wheel well cubbies in the trunk. I decided to buy a JL sub just to keep my components from the same manufacturer, for no better reason than that I knew JL made good components and my OCD likes having everything uniform. I grabbed a JL 10W1V2 subwoofer, since its volume requirements fit the AI box and it had good reviews.

View of the empty trunk

Finally, I drew up a whole system diagram and estimated how much wire and overbraid I’d need for the install, and made sure I had all the hardware I’d need. I’ve always found the most frustrating thing in the world is getting partially through an install and finding that you don’t have one piece of hardware to finish it up. I ordered all the stuff from Crutchfield, and sat on the edge of my chair until it arrived a week or so later.

Once I received all the components, I wired it together on my bedroom floor with a lab power supply stolen from one of my roommates, to make sure I knew how I was going to hook it up. I wired up a potentiometer with a built-in switch to the remote volume control and the remote turn-on inputs of the amplifier in place of the stock remote volume knob. The pot replaces the remote volume control, while the switch mechanism disables the remote-on line. I terminated the control lines from the pot into a short pigtail with a connector on the end, so that I could modify it or replace it down the line without modifying the other amp wiring if I need to.

Finally, install day rolled around. My buddy James drove down from LA to assist and advise, since he’s had some experience with previous audio installs. I decided to tackle routing the power cables first. I had purchased some 4AWG power wire to use for power and ground from the amp. I lucked out in that Volkswagen has a big distribution bus bar in the main fusebox under the hood with a few empty positions. This made it really easy to mount a fuse and source power for the amp.

Fuse block with purple audio fuse on the right.

I had to modify the front of the fuse block a little by cutting down some of the plastic below the bus bar to provide clearance for the new terminal. However, you can’t see the modified bits at all when the fuse box cover is installed. In the photo above, you can see the 4AWG wire in black overbraid running below the front of the fuse box and the purple 60A fuse I used for the amplifier.

Fuse box with cover installed

Routing the power wire through the firewall also turned out to be easier than I had anticipated. I found a large rubber boot with the main engine harness running through it just behind the battery box. This boot had a number of small “nipples” on it for additional harnesses to run through, so I clipped off one of the spare nipples and fed the power wire through from the passenger compartment. The rubber boot forms a very tight seal against the cable insulation, so I’m not concerned about water being able to migrate in from the engine compartment.

The boot going through the firewall through which I fed the power cable.

To route the power cable to the amplifier location under the seat required removing a large plastic panel under the steering wheel, several trim pieces near the door, and the drivers’ seat. I had heard that disconnecting the airbag harness going to the drivers’ seat can cause issues with the airbag system, so I did not completely remove the seat but rather just removed the hold-down bolts and slid it into the rear seat footwell. I removed the door sill trim piece, and the trim piece that the hood release mounts to.

Routing the power wire into the passenger compartment.

I routed the power cable down underneath the door sill and then out under the seat. There’s a pretty sizable tunnel under the door sill that made routing the cable very easy. I also found a large grounding bolt in the tunnel which I decided to use for the amplifier ground. I’m not sure what the ground wire attached to the bolt goes to, but based on subsequent events (keep reading) I think it might be associated with the airbag system.

Amplifier ground wire attachment to ground stud.

I ran the ground wire up the tunnel under the drivers’ seat along with the power wire. With the power cables routed, my next step was to wire in to the back of the head unit. Following some instructions I found online, I pulled the dashboard apart, and removed the head unit. Once I had access to the head unit harness, I used some Positaps to connect a length of 8-conductor shielded 24AWG wire to the rear speaker outputs. I used four of the conductors to carry the line-level audio to the amp, two for the level control, and one for the remote-turnon, leaving one spare conductor.

Dashboard pulled apart and the radio harness hanging out.

After tapping the speaker outputs, I reinstalled the head unit and put the dash back together. I routed the cable from the rear of the head unit down through the center tunnel and then out under the driver’s seat. I pulled out the ashtray assembly and mounted the level control pot on one of the blank switch plates next to the ESP switch. I had to cut away a decent bit of plastic from the ashtray assembly to clear the pot body, and I’m not very happy with the mounting, so I’ll probably re-do it one of these days when I have some down-time.

Underneath the ashtray assembly

The last step before actually installing the amp was to route the wires back to the sub. This actually turned out to be substantially easier than I had feared. I was figuring I’d have to route the wires under the carpet and possibly remove the back seat to get them back to the trunk cleanly. As it turns out, however, I was able to just slide them under the plastic trim panels along the side of the car and then along the side of the rear seat. I pulled up the carpet covering the spare tire and ran the wire along the styrofoam that holds the spare in place. In this picture, you can barely see the wire in its black overbraid next to the lower rear seat bolster and right near the hinge where the seat folds down:

Wire routing back to the sub.

Finally, I installed the amp itself under the drivers’ seat. This required terminating the volume control wires in a 3.5mm audio plug, splicing the speaker level inputs to the JL-supplied connector pigtail, and connecting the remote turn-on wire to the remote input on the amp. I connected the 4AWG power wires as well as the sub outputs.

Wiring up the amplifier.

I was pretty squeamish about drilling holes in the floor to attach the amp, so I decided to go with the tried and true velcro mounting method. I put some large velcro adhesive patches to the bottom of the amp, and stuck it in place on the floor. Frequent removal would probably tear up the carpet pretty badly, but I don’t anticipate I’ll be pulling the amp out frequently. Here’s the final amp install:

Final amplifier install under the driver's seat.

The amp is completely stealth when the driver’s seat is in a normal driving position. It can only be seen if you’re really looking for it:

Invisible amp install

The sub box install was ridiculously easy. Audio Integrations makes a really well-built product that just dropped right in. The only hitch I ran into was getting the installation bolts to slide cleanly into the enclosure, so I dropped a 1/4″ drill bit into the installation holes to smooth and widen them out a little. The final installation is really clean, and almost looks stock because Audio Integrations did a really good job of matching the OEM carpet:

Subwoofer installation

I’m really pleased with the install… I think the 10″ sub is a perfect fit for the stock stereo. With the amp volume control set about halfway, the system sounds pretty well balanced. If I want to really shake and do some hearing damage, I can turn it up all the way and get all the mirrors shaking. I’ve got a few outstanding issues with the install that I need to fix:

• The airbag warning light came on right after the install, along with a MFD warning saying “Airbag Fault”. I’ve read mixed stories on the forums about this issue. Some people have reported the same issue from just disconnecting the battery, but other people have said it’s an indication of some larger problem. I’m mildly concerned that disconnecting that ground wire to install the amp ground might have caused the fault condition. I’ll be taking the car in to the dealer in a week or two for the 20,000 mile service, so I guess I’ll find out then what the issue is.
• The pot that I used for the level control is a linear-resistance pot. Unfortunately, it looks like the amp level control is designed for a logarithmic “audio” pot. I’m hunting around for a suitable replacement log pot, but for the time being it’s usable. The effect of using a linear vs a log pot is that the useful range of the pot is compressed to one end of its rotation. Most of the volume control takes place in the first 1/4 turn of the pot. I’m still shopping around for a suitable audio pot, but one of these days I’ll swap it out.

*UPDATE 6/12/2010* I brought the GTI in to the dealer, and the airbag fault code was apparently due to an unexpected open circuit on the passenger airbag warning light in the center of the dash. This was due to me disconnecting it while pulling the dash apart to get at the back of the head unit, even though I reconnected it when I was done. It might be possible to pull the dash apart without disconnecting this light, but I haven’t tried it.Anyway, the dealer cleared the fault code at no cost, and now everything’s back to normal.

Apple, being Apple, decided to make it im-freaking-possible to get into the guts of the Airport Express. The case is two halves of thick plastic ultrasonically welded together, making it a serious pain in the ass to get it open. I tried prying it apart with a series of screwdrivers:

Attempting to pry it open

This was the wrong way to go about it. After a half hour of struggling with various sizes of screwdriver, I got impatient and grabbed my hand-saw. I carefully sawed around the three sides without the connectors. I tried to saw down the plastic until I was just starting to break through to the inside of the box, but this was pretty tricky in spots. Eventually I got impatient and went back to the screwdrivers:

Back to screwdrivers

After a good bit of prying and swearing, I managed to get the thing open. The Airport Express internals are split into two halves… a power board, and the airport-express-stuff board, with just a power cable connecting the two:

Halved

Once the Airport Express is open, there are a few screws holding the Airport motherboard in place. I pulled those screws and then popped the metal shielding off of the board.

Airport motherboard

Here’s what the two boards look like after yanking them from the plastic shells:

The boards

The motherboard is actually made out of two boards. The larger board holds all the RF and computing stuff, and the smaller daughterboard holds the audio interface circuit. Here’s a pic of the two separated:

Board and Daughterboard

Here’s the back side of the motherboard:

Back of the motherboard

Next, I sat down to try to figure out what was wrong with the airport express. I tossed a volt-meter on the power supply outputs and plugged it in, and it turns out the power supply was shot. Neither the 5V or 3.3V outputs were pumping out any juice. I briefly considered trying to troubleshoot the supply, but I decided it was easier jut to chuck it  and throw some wall-warts on the inputs. I had a 3.3V wall-wart, but no 5V supply, so I used the 3.3V supply and a 12V supply running through a TI PT5101A 5V, 1A switching power supply:

Complete with warts

Unfortunately, the 3.3V and 12V wall warts I had sitting around were only 300mA and 500mA supplies, whereas the Airport Express’s original power supply was spec’d at 1.21A and 0.7A for each voltage. I was hoping that the Airport wouldn’t require that much power to operate, but it turns out that it does. When I plugged the power supplies in, the green LED briefly lit up and slowly faded out. I’m going to try to hunt down some more powerful supplies and try again.

I cracked the case open using a combination of an xacto knife and a little metal scale. You’ve got to be careful that you don’t scratch or cut the plastic case while doing this, so I’d recommend using something made out of nylon or other plastic to do this. All I had was the Xacto and scale though, and I managed to get it open without butchering the plastic too badly:

Opening the case

After carefully working around the outside of the case, the two halves just pop apart, revealing the hard drive and connector circuit board:

Inside the case

Here’s another view of the input circuit board, the hard drive, and the ribbon connector that connects to the main circuit board:

Side view

Gently pulling on the ribbon connector frees it from the main circuit board, and the two halves can be separated:

Halved

Once the iPod is in half, it’s easy to remove the hard drive. It’s not screwd in or anything, just held in by the pressure of the two case halves. Pull the cable out of the end of it, and you end up with:

HDD removed

If you were to replace the hard-drive, you’d have to pull the rubber bumper off of the perimeter of it, and the foam backing off the back side.

Hard drive padding

From here, it’s possible to remove the main PCB by unscrewing the Torx T6 screws that hold it in place, and removing the battery connector in the lower right. There’s also a little flex cable that runs to the buttons on the front that you will have to disconnect:

Removing the main PCB

Here are all the guts laid out together:

Guts

And as proof that I’m at least *somewhat* better than a five-year-old, here’s a video of the reassembly:

I keep running across more and more stuff that is just begging to be torn apart. It’s like I’m 5 years old all over again, except this time I have screwdrivers instead of just rocks and sticks. Anyway, this time around, I tore down my roommate’s Canon Powershot SX100IS camera. It’s been having some issues with a stuck shutter, so we tried to pull it apart and fix it. Following are the results of that attempt:

First off, there were about 10 or so screws to remove from the outside of the case. Some were hidden in the battery compartment, others underneath a little removable trim panel, others in the little port flap on the side. They’re tricky to find, so don’t start prying at the case until you’re sure you’ve pulled all the screws.

Removing exterior screws

The SX100IS has a cool little memory backup battery that just slides into the side of the camera that can be seen above the pile of screws in the pic above.

After removing the side trim

The camera has a little side trim piece that’s hiding another couple of screws that hold the front and back of the camera on. Once those screws are removed, it’s possible to pop the entire front of the camera off. First, though, you have to pop off the top of the camera, which should be loose at this point if you pulled all the other screws from the outside.

Pulling off the top

After pulling the top off, you can remove the front plastic piece:

Removing the front

Here’s what the inside of the front of the camera looks like:

Inside the front

You can see the flash board off to the side of the lens, and the lens motor on the other side. After the front is off, the back can be pulled in a similar manner, but watch out for the flex cable connecting the buttons on the back to the PCB.

Inside the back of the camera

In our quest to remove the lens assembly, I decided it was a good idea to pull the LCD and the pcb off of the back of the camera. The LCD has two connectors, one for the backlight, and one for the LCD data… make sure to disconnect both before pulling the LCD.

Pulling the LCD

After removing the LCD and the PCB, it is possible to see the back of the CCD assembly:

Back of the CCD

Next I yoinked off the flash driver board on the front of the camera to see if there was any way to get at the lens mechanism that way.

Flash driver board

At this point, we came to the conclusion that we weren’t getting anywhere trying to get at the shutter, so we decided it was time to put the camera back together. This was pretty straightforward, with the exception of plugging some of the flex cables back in. The trick here is that the sockets they plug into have little black parts at the front that flip down to clip the cable in place. One of these can be seen on the LCD cable below:

LCD cable insertion

Anyway, those are all the pictures I took. We managed to get the camera put back together with only two extra screws! It still powers up and everything works on it, but the shutter is still broken so the whole exercise was kind of pointless, except for the educational and entertainment value.

Anyway, I’m the webmaster for the group, so I’ve been working on getting a website together. I grabbed a .tk domain name for the website, so that we don’t have to deal with the horrible Georgia Tech hosting url. Anyway, the site’s at http://www.pneumaniacs.tk if you want to see what we’re up to. I’ll be updating it throughout the semester as we get more work done on the project.

The template for the Obama Cubecraft is available on Cubecraft’s site. It’s a limited edition, so grab it while you can.

Obama Template (click to see full-sized on on Cubecraft's site)

I printed the template out on some heavy cotton resume paper that I happened to have sitting by my printer. Turns out I somehow managed to mess up the printer settings and ended up lopping off the lowest 1/4″ or so of the image. More about this later.

To cut out the parts, I grabbed my trusty Xacto knife. It’s very important to use a brand new blade, as an even slightly dull one will tear rather than slice the paper. I started off with an older blade, and managed to make a few nasty cuts. I grabbed a brand new blade, and the cuts got much cleaner and easier to make. Interestingly, I observed that the blade got noticably duller by the time I was done cutting. Who knew paper could dull a steel blade so quickly?

Cutting out the Obama shapes

Removing the cut bits from the printed template

After carefully cutting out all five of the shapes (two arms, a torso, a head, and pants), it was time to fold them. Depending on how thick your paper is, you may have to lightly scribe the back-side of the fold lines with the Xacto knife to get good clean folds. My paper was thin enough that I just grabbed a small stainless steel scale I had on my desk and used its edge to get straight, clean edges on my folds.

Folding the head

After creasing all of the folds, we begin the actual assembly process. This is a straightforward tongue and slit assembly, and requires no tape or glue if you do it right. All of the tongues and slits are lettered, so assembly is pretty obvious. One trick that will make your finished figure more durable is to bend the “ears” on each tongue slightly so that they are less likely to slide out of the slit once assembled.

Obama's head coming together

I mentioned above that I had some trouble with my page settings when I printed, so I lost abou 1/4″ of the template. The result of this was that I lost tabs “R”, “S” and “i”. The first two tabs connect the torso to the head, and the last one holds Obama’s hand closed. I didn’t discover the problem until I had already cut everything out, so I was reluctant to re-print the template and do more cutting. I grabbed out my handy-dandy scotch tape and just taped the hand closed and taped the head to the torso:

The hand missing tab "i"

The head/torso junction missing tabs "R" and "S"

I also had to extend the slits where the arms mount by about 1/8″ in order to keep them from interfering with the head/torso joint. This would not be a problem if I hadn’t printed the template incorrectly. Anyway, after some judicious application of the knife and some tape, I got the finished figurine:

The Phone

I didn’t take any pictures of the disassembly process, but here are the pics of the guts (click for higher res version):

Good view of the membrane keyboard and the back of the main PCB on the left.

View of the PCB for the front of the clamshell, including the screen and speaker.

The front of the main PCB and the main screen on the right. Interesting things on the main PCB are the SIM card connector and the grounding between the RF circuits toward the top of the main PCB and the rest of the board.

Parts everywhere! Notice there are two sets of plastic in this pic... the old case and the new one.