Refurbishing Armored Tablets

July 4, 2016 by Elliot Williams 10 Comments

Who can resist the insane deals on bizarre hardware that pop up on auction websites? Not [Dane Kouttron], for sure. He stumbled on Armor X7 ruggedized tablets, and had to buy a few. They’d be just perfect for datalogging in remote and/or hostile locations, if only they had better batteries and were outfitted with a GSM data modem… So [Dane] hauled out his screwdrivers and took stuff apart. What follows is a very detailed writeup of the battery management system (BMS), and a complete teardown of this interesting tablet almost as an afterthought.

First, [Dane] tried to just put a bunch more batteries into the thing, but the battery-management chip wouldn’t recognize them. For some inexplicable reason, [Dane] had the programmer for the BMS on-hand, as well as a Windows XP machine to run the antiquated software on. With the BMS firmware updated (and the manufacturer’s name changed to Dan-ger 300!) everything was good again.

Now you may not happen to have a bunch of surplus X7 ruggedized tablets lying around. Neither do we. But we can totally imagine needing to overhaul a battery system, and so it’s nice to have a peek behind the scenes in the BMS. File that away in your memory banks for when you need it. And if you need even more power, check out this writeup of reverse-engineering a Leaf battery pack. Power to the people!

Looptaggr: Endless Graffiti

July 4, 2016 by Elliot Williams 20 Comments

If your problem is how to put out a maximum amount of repetitive graffiti with a minimum amount of effort, we’ve got your solution. Or rather, [Ariel Schlesinger] and [Aram Bartholl] had your solution way back in 2010. The banner image says it all.

Of course, it doesn’t have to be graffiti that you’re spraying. This idea could be easily adapted to stencil that repeating floral pattern that my grandmother had on her walls too. It’s like a patterned paint roller, but for a spray can.

There’s room for improvements here. For instance, we can’t cut out stencils to save our life but we know where to find a laser cutter. From the look of things, they could use a slightly bigger stencil and something to catch the drips. There’s probably an optimal size for this gizmo, which calls for experimentation.

We’re somewhat obsessed with graffiti machines. Whether it’s a graffiti quadcopter or the elegant and non-permanent sidewalk-chalker style bots, we like machines that make “art”. What’s your favorite graffiti hack?

Thanks [n0p;n0p;n0p;] for the (archival) tip!

Custom Firmware Unlocks Fitness Tracker

July 3, 2016 by Elliot Williams 17 Comments

[Mikhail] sent us a teaser video for a hack he’d done (embedded below). He takes a Bluetooth LE fitness tracker dongle and reflashes it spit out the raw accelerometer data and trigger events. He then wrote a phone app that receives the data and uses the device as an alarm, an on/off switch, a data-logging device, and more.

We thought it was cool enough that we asked [Mikhail] for more detail, and he delivered in spades! Inside the device is a Nordic NRF51822, their ARM Cortex + Bluetooth chip, an accelerometer, and a bunch of LEDs. [Mikhail] mapped out the programming headers, erased the old flash, and re-filled it with his own code. He even added over-the-air DFU re-flashing capability so that he wouldn’t have to open up the case again.

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Mechanical Horse-Bike

July 2, 2016 by Elliot Williams 18 Comments

Oh [Rodger Cleye]! You had us at “unicycle, duct tape, styrofoam, and tie wraps”. But watching the horse-bike in action (video below) is just about enough for us to go out and make one ourselves. (For our child, naturally. We’re far too dignified.)

If you trawl around [Rodger]’s YouTube channel, you’ll see no end of odd motorized vehicles. Like last year’s motorized horse project, or this stormtrooper speeder. But there’s just something about the way that the horse’s legs move along with the rider that is slightly more enchanting. (That’s the “unicycle” part of the build.) And, we assume, the rider gets a little bit more exercise to boot.

We’ve featured a few builds of [Rodger]’s before, including his motorized couch build that’s obviously controlled from the seat-mounted coconut, and of course a pneumatic Boba Fett rocket.

Horrible Macro Rig Makes Good Photos

July 1, 2016 by Elliot Williams 19 Comments

We love horrible hacks like this. It’s a lens and a ring of LEDs, taped to a cell phone. Powered through crocodile clips, also taped to the cell phone. There’s nothing professional here — we can think of a million ways to tweak this recipe. But the proof of the pudding is in the tasting.

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What Could Go Wrong: SPI

July 1, 2016 by Elliot Williams 58 Comments

Serial Peripheral Interface (SPI) is not really a protocol, but more of a general idea. It’s the bare-minimum way to transfer a lot of data between two chips as quickly as possible, and for that reason alone, it’s one of my favorites. But that doesn’t mean that everything is hugs and daffodils. Even despite SPI’s simplicity, there are still a few ways that things can go wrong.

In the previous article in this series, inspired by actual reader questions, I looked into troubleshooting asynchronous serial connections. Now that you’ve got that working, it’s time to step up to debugging your SPI bus! After a brief overview of the system, we’ll get into how to diagnose SPI, and how to fix it.

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200W Laser Bazooka Is Just Silly

June 30, 2016 by Elliot Williams 79 Comments

We weren’t going to run this one, because, well, it’s just ridiculous. But enough of you have browbeat us by sending in tips to the tipline that we’re going to capitulate. We’re not going to name you all by name, because really, you should be ashamed of yourselves. But you know who you are!

[Styropyro] does a lot of crazy things on YouTube. We really liked his “stuff in a microwave oven” series. He’s also obsessed with lasers and popping black balloons. So he took the laser heads out of four DLP computer projectors (the ones with 24 of those 1.5W Nichia diodes) and combined them. Yup, 200W of ~~405~~ 445nm blue.

Then he just straps them together and passes them through a lens. It’s not a tight beam, but this thing is really bright. Even though the beam is very loosely focused, it burns stuff. That’s about all you can say. Lots of laser. Boy Howdy!

OK, there, we ran it. Don’t do this at home. It doesn’t require much finesse, and it’s going to get someone blind. Much better to expend your efforts on something more civilized like a projector. At least then you can play vector games on the wall. And stay off my lawn!!! (Kids these days…)

For those that do want to burn stuff, [Joshua Vasquez] published an article yesterday about building a safe laser cutter… much more worth your energy than anything billed as a laser bazooka.

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