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Hardware hacking how-tos

Navigate Around Garmin’s Custom Map Limits

October 4, 2019 by 23 Comments

If your only experience with Garmins is from that one rental car a few years back, it may surprise you that some of them, mostly the handheld outdoor units, allow custom maps. This sounds cool until you find out the limitations. Unless you upgrade to premium, it doesn’t allow map files larger than 3MB. What’s worse, it will choke the resolution of maps larger than one megapixel. Well, bust out your virtual hiking boots, because [facklere]’s gonna take you down the trail of DIY digital cartography.

You can use any map you want as long as its not completely fictional (although wandering the maps of middle-earth would be a fun hack on top of this one). Your map can be paper, PDF, or parchment; it just has to be converted to JPEG. The map [facklere] wanted to use was a huge PDF, so as a bonus, he shows how to get from PDF to JPEG in GIMP. Then comes the fiddly part — rooting the map in reality by overlaying it on real roads using Google Earth.

You’ve still got a huge map. Now what? The secret sauce is tiling. [facklere] used KMZfactory, a free map editor for Garmin maps that goes the extra mile to split the tiles for you, keeping them under the 1MP limit. Once that’s done, just upload it to your unit and hit the road.

Got an old Garmin that won’t do custom maps? See if you can get DOOM up and running on it.

Solve Your Precision Woes With A Sliding Angle Grinder

October 3, 2019 by 9 Comments

Angle grinders are among the most useful tools for anyone who’s ever had to cut metal. They’re ergonomic, compact, and get the job done. Unfortunately, one of the tradeoffs you usually make when using them is precision.

But thankfully, there’s a DIY solution. YouTuber [workshop from scratch] demonstrated the build process for a sliding angle grinder in a recent video, welding steel beams into a flat frame and attaching fitted beams on top to slide across the rows. Where necessary, spacers are used to ensure that the slider is perfectly fitted to the beam. The contraption holding the angle grinder – a welded piece of steel bolted to the sliding mechanism – has a grip for the user to seamlessly slide the tool across the table.

The operation is like a more versatile and robust chop saw, not to mention the customized angle references you can make to cut virtually anything you like. The build video shows the entire process, from drill pressing and turning holes to welding pieces of the frame together to artfully spray painting the surface a classy black, with familiarity enough to make the project look like a piece of cake.

As the name implies, [workshop from scratch] is all about building your own shop tools, and we’ve previously taken a look at their impressive hydraulic vise and mobile crane builds. These tools, largely hacked together from scraps, prove that setting up your own shop doesn’t necessarily mean you need to break the bank.

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Fried Desk Lamp Reborn: How To Use ESP8266 To Build Connected Devices

October 1, 2019 by 9 Comments

Some hacks are born of genius or necessity, and others from our sheer ham-fisted incompetence. This is not a story about the first kind. But it did give me an excuse to show how easy it is to design WiFi-connected devices that work the way you want them to, rather than the way the manufacturer had in mind.

It started out as a sensible idea – consumer electronics in Vietnam have many different electric plug types for mains AC power: A, C, G, F, and I are fairly present, with A and C being most common. For a quick review of what all those look like, this website sums it up nicely. There are universal power adapters available of course, but they tend to fit my most common type (C) poorly, resulting in intermittent power loss whenever you sneeze. So I figured I should replace all the plugs on my devices to be A-type (common to those of you in North America), as it holds well in all the power bar types I have, mainly leftover server PDUs.

This was very straightforward until I got to my desk lamp. Being a fancy Xiaomi smart lamp, they had opted to hide a transformer in the plug with such small dimensions that I failed to notice it. So instead of receiving a balmy 12 volts DC, it received 220 volts AC. With a bright flash and bang, it illuminated my desk one final time.

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The Zen Of Mechanical Keyboard Wiring

September 27, 2019 by 24 Comments

Mechanical keyboards are all the rage right now, but the vast majority of them are purchased commercially. Only the most dedicated people are willing to put in the time and effort required to design and assemble their own custom board, and as you might imagine, we’ve featured a number of such projects here on Hackaday in the past.

But what makes this particular mechanical keyboard build from [kentlamh] so special isn’t the final product (though it’s certainly quite nice), but the care he took when hand-wiring all of the switches to the Teensy 2.0 microcontroller that serves as its controller. There’s no PCB inside this custom board, it’s all rainbow colored wires, individual diodes, and the patience to put it all together with tweezers.

[kentlamh] takes the reader through every step of the wiring process, and drops a number of very helpful hints which are sure to be of interest to anyone who might be looking to embark on a similar journey. Such as bending the diode legs en masse on the edge of a table, or twisting them around a toothpick to create a neat loop that will fit over the pin on the back of the switch.

He also uses a soldering iron to melt away the insulation in the middle of the wires instead of suffering through hundreds of individual jumpers. We’ve seen this trick before with custom keyboards, and it’s one of those things we just can’t get enough of.

Some will no doubt argue that the correct way to do this would be to use an automatic wire stripper, and we don’t necessarily disagree. But there’s something undeniably appealing about the speed and convenience of just tapping the wire with the iron at each junction to give yourself a bit of bare copper to work with.

Even if you aren’t enough of a mechanical keyboard aficionado to travel all the way to Japan to attend the official meetup or discuss the finer points of their design at the Hackaday Superconference, there’s an undeniable beauty to this custom board. With a little guidance from [kentlamh], perhaps it will be your own handwired masterpiece that’s next to grace these pages.

[Thanks to Psybird for the tip.]

Pizza Oven Build Exercises Forgotten Gym Ball

September 18, 2019 by 6 Comments

See, this is what happens when pizza lovers follow their dreams. It probably started innocently enough for [phammy57]—he got a pizza stone, then maybe one of those big rocking pizza cutters. Maybe he even learned how to toss the dough high in the air. But every time [phammy57] slid one of those homemade pies into the electric oven, the nagging feeling grew a little stronger. Eventually, he gave in to making pizza the way it’s supposed to be made, and built a wood-fired oven.

The most intriguing thing about this build is also the most important: this pizza preparer pivots on a gym ball, which served as the base for forming the oven. To do this, [phammy57] pushed the ball halfway through a hole in a big piece of plywood, effectively creating the world’s largest Pogo Bal (remember those?). Then he applied plastic wrap to the ball as a mold release, and laid down a thick mixture of vermiculite, cement, and water.

[phammy57] built the base from lightweight blocks, sculpting a nice arch for the top of the wood storage area. Once the dome was fastened to the base with the opening cut and outlined with brick, he cut a vent hole and built the chimney. Finally, it was time to add insulating blanket material, chicken wire, more vermiculite, and coat of plaster to finish. Take a brief look inside after the break.

It’s a long process of building, curing, and burning in, but the end result looks fantastic. We bet it pizzas like a champ, too. Probably gives this 45-second pizza oven a run for its money.

[Ed Note: If you’re still having trouble parsing the title, try it out with “build” as a noun and “exercises” as a verb.]

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Basic Acrylic Bending, No Special Tools Needed

September 16, 2019 by 24 Comments

Acrylic sheets are relatively inexpensive, pretty, and can be heat-shaped very effectively. There are blades and tools made specifically for cutting, heating, and bending acrylic but [Marija] shows that even without them acrylic can be cut and bent with a bit of care and patience.

Acrylic sheets are brittle and crack easily, but a hacksaw is a good way to cut it by hand. After cutting, [Marija] uses a small portable gas stove at its lowest setting to provide gentle heat until the acrylic becomes soft, then it can be formed into different shapes using common shop and household items. It’s a process that requires patience and practice, so she shares some useful tips:

  • Remove the protective film after cutting, but before heat forming. Otherwise the film will be much harder to remove.
  • Heating too aggressively will result in bubbles that ruin the acrylic.
  • Uneven heating will result in a bad bend, or “hot spots” which can result in bubbles as mentioned above.
  • This heating method naturally softens a wide area, but it’s still possible to get straight and flat bends by using wood forms and letting the acrylic cool before moving it.

[Marija] used this method of heating and bending acrylic to complete an earlier lamp project of hers that we featured in the past. Acrylic might laser-cut beautifully, and there may be inexpensive tools for heating and bending it, but it’s always nice to have some tried and true techniques that don’t require anything special.

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These Tips Make Assembling A Few Hundred PCBs Easier

September 12, 2019 by 7 Comments

There are a few common lessons that get repeated by anyone who takes on the task of assembling a few hundred PCBs, but there are also unique insights to be had. [DominoTree] shared his takeaways after making a couple hundred electronic badges for DEFCON 26 (that’s the one before the one that just wrapped up, if anyone’s keeping track.) [DominoTree] assembled over 200 Telephreak badges and by the end of it he had quite a list of improvements he wished he had made during the design phase.

Some tips are clearly sensible, such as adding proper debug and programming interfaces, or baking an efficient test cycle into the firmware. Others are not quite so obvious, for example “add a few holes to your board.” Holes can be useful in unexpected ways and cost essentially zero. Even if the board isn’t going to be mounted to anything, a few holes can provide a way to attach jigs or other hardware like test fixtures.

[DominoTree] ended up having to attach multiple jumper wires to reprogram boards after assembly, and assures us that “doing this a bunch of times really sucked.”
Other advice is more generic but no less important, as with “eliminate as many steps as possible.” Almost anything adds up to a significant chunk of time when repeated hundreds of times. To the basement hacker, something such as pre-cut and pre-tinned wires might seem like a shameful indulgence. But cutting, stripping, tinning, then hand-soldering a wire adds up to significant time and effort by iteration number four hundred (that’s two power wires per badge) even if one isn’t staring down a looming deadline.

[DominoTree] also followed up with additional advice on making assembly easier. Our own [Brian Benchoff] has also shared his observations on the experience of developing and assembling a large number of Hackaday Superconference badges, including what it took to keep things moving along when inevitable problems surfaced.

You don’t need to be making batches of hundreds for these lessons to pay off, so keep them in mind and practice them on your next project.