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Hackaday Links: February 1, 2015

It’s Sunday evening, and that means Hackaday Links, and that means something crowdfunded. This week it’s UberBlox. It’s a modular construction system based on Al extrusion – basically a modern version of an Erector set. Random musings on the perceived value UberBlox offers in the comments, I’m sure.

[Trevor] sent in something from his Etsy shop. Normally we’d shy away from blatant self-promotion, but this is pretty cool. It’s reproductions of 1960s Lockheed flying saucer plans. We’re not sure if this is nazi moon base/lizard people from the inner earth flying saucer plans or something a little more realistic, but there you go.

3D computer mice exist, as do quadcopters. Here’s the combination. It looks like there’s a good amount of control, and could be used for some aerobatics if you’re cool enough.

Who doesn’t love LED cubes? They’re awesome, but usually limited to one color. Here’s an RGB LED cube. It’s only 4x4x4, but there’s a few animations and a microphone with a beat detection circuit all powered by an ATMega32u4.

A while ago we had a post about a solar powered time lapse rig. Time lapse movies take a while, and the results are finally in.

BMW Remote Unlock Wasn’t Using Secure HTTP

Ah, the old HTTP versus HTTPS. If you want to keep people out, that trailing ‘S’ should be the first thing you do, especially if you’re trying to keep people out of a luxury automobile. It turns out that BMW screwed up on that one.

BMW has an infotainment feature called ConnectedDrive which builds your favorite apps and services right into the dashboard. You can even unlock the vehicle using this system which is built around a piece of hardware that includes a GSM modem and permanent SIM card. A security research group recently discovered that the commands sent for this system were being pushed over HTTP, the unencrypted sibling of HTTPS. The firm, hired by German automobile club ADAC, disclosed the vulnerability and an over-the-air upgrade has already been pushed to patch the flaw. The patch is described to have “turned on” the HTTPS which makes us think that it was always meant to be used and just configured incorrectly in the roll-out. We’ll leave you to debate that point in the comments. Seriously, how does something like this happen? It certainly sheds a lot more light on thieves being able to magically unlock high-end cars. Was this how they were doing it?

[Thanks Fabian]

Building A Modern Retro Console

There are a few dozen classic re-imaginings of classic game consoles, using hardware ranging from the ATMegas of the Uzebox to everyone’s favorite, stuffing some ROMs on a Raspi and calling it a day. You don’t necessarily learn anything doing that, which puts [Mike]’s custom game console head and shoulders above the rest.

The build started off as a plan for a Z80 computer with a dual ATMega GPU. He progressed far enough in the design where it would have been a masterpiece, but the inability to mill double-sided boards at home killed the design. Plans then moved on to an FPGA, then to an ATMega with the Analog Device AD725 PAL/NTSC encoder chip. That idea had a similar architecture to the Uzebox, but [Mike] wanted more power. He eventually settled on a PIC32 with the AD725.

This setup was capable of pumping out some impressive graphics, but for moving bits to a screen, you need DMA. [Mike] ran into a problem where the DMA timer runs at a maximum rate of 3.7 MHz. It’s a problem documented in a few projects, leading [Mike] to change his plan once again, this time to the STM32F4.

The bugs are worked out, and now [Mike] can stream a whole lot of pixels to a screen while still having some processing power left over to play a game. It’s a project that’s more than a year and a half old at this point, and so far he’s learned a lot.

Give Your Multimeter A Wireless Remote Display

Multimeters are one of the key tools in a hardware hacker’s bench. For 90% of us, the meter leads are perfect for making measurements and looking over at the results. Sometimes you need a bit more distance though, and for that, [Ken Kaarvik] has created the Multimeter remote display. Remote displays are pretty handy when you want to measure something several feet away from your bench. They’re also great if you need to check something in an enclosed space, like a server rack or a refrigerator. Fluke actually sells multimeters with wireless displays, such as their model 233.

The key to this project is the FS9721 LP3 chip by Fortune Semiconductor. (PDF link) The FS9721 is essentially a system on chip (SOC) for multimeters. It contains a digital to analog to digital converter, an LCD driver, and a microcontroller. It also can send data out over a 2400 baud serial link. Two of [Ken’s] multimeters, the Digitek DT-4000ZC and a Fluke 17B, both have this chip. The Digitek has a 1/8″ plug for connecting to the outside world, while the Fluke requires some simple hardware mods to enable data output.

Since this was his entry for the Trinket EDC contest,  [Ken] connected the serial output of the FS9721 to an Adafruit Pro Trinket. The Trinket formats the data and sends it to an  nRF24L01+ 2.4GHz radio module. The receiving end has an identical radio, and another Pro Trinket. [Ken] actually built two wireless displays. One is a dual-boot Game Boy advance which has a really slick background on the color display. The other receiver utilizes a 128×64 OLED. The trinket, nRF24L01+ and display all fit neatly inside an Altoids tin.

Click past the break to see both wireless remote displays in action!

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Autonomous Vehicle-Following Vehicle

Humanity has taken one step closer to Skynet becoming fully aware. [Ahmed], [Muhammad], [Salman], and [Suleman] have created a vehicle that can “chase” another vehicle as part of their senior design project. Now it’s just a matter of time before the machines take over.

The project itself is based on a gasoline-powered quad bike that the students first converted to electric for the sake of their project. It uses a single webcam to get information about its surroundings. This is a plus because it frees the robot from needing a stereoscopic camera or any other complicated equipment like a radar or laser rangefinder. With this information, it can follow a lead vehicle without getting any other telemetry.

This project is interesting because it could potentially allow for large convoys with only one human operator at the front. Once self-driving cars become more mainstream, this could potentially save a lot of costs as well if only the vehicle in the front needs the self-driving equipment, while the vehicles behind would be able to operate with much less hardware. Either way, we love seeing senior design projects that have great real-world applications!

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Spline Thieving Makes Hobby Servos Even More Useful

For years the proprietary spline pattern of rc servos has been a dealbreaker for hobbyists who want to add custom shafts and gears to their servos. First, different servo sizes have different spline sizes, and each vendor equips their servos with different patterns. True, some special vendors sell custom gears that mate to these patterns, but, overall, the hard-to-replicate pattern has severely limited the output options for servos.

This pattern didn’t deter [JB], however. With some clever CAD skills, and two working implementations, he’s demonstrated that these spline patterns can be (1) harvested and (2) added into custom components, opening a new suite of design opportunities involving servos.

To capture the spline, [JB] imports an image into Solidworks, and traces the pattern on a properly scaled image. From there, he can embed this pattern directly into a physical model for fabrication.

To make parts that preserve this pattern, [JB] has two options. With his FormLabs printer, he can print components that already have the pattern feature, allowing him to press-fit custom links directly onto servos. Alternatively, for a sturdier component, he presents the milling method. With this technique, he drills a circle of bolt holes onto the desired output shaft and then mills out the center. From here, the shaft can also be directly pressed onto the servo spline where each spline groove fits snugly into the edge of the previously-drilled holes.

So, how well do they work? According to [JB] he’s actually managed to do some damage to himself before damaging to the 3D-printed part while trying to strip the pattern. The end-goal is to insert these shafts into transmissions for a miniature combat robot, another one of [JB’s] projects which is well-underway. Until then, we’re looking forward to seeing more servos tightly-integrated into upcoming projects.

Emergency Power Based On Cordless Drill Batteries

[Don Eduardo] took matters into his own hands after experiencing a days-long power outage at his house. And like most of us have done at least one, he managed to burn his fingers on a regulator in the process. That’s because he prototyped a way to use power tool batteries as an emergency source — basing his circuit on a 7812 linear regulator which got piping hot in no time flat.

His next autodidactic undertaking carried him into the realm of switch-mode buck converters (learn a bit about these if unfamiliar). The device steps down the ~18V output to 12V regulated for devices meant for automotive or marine. We really like see the different solutions he came up with for interfacing with the batteries which have a U-shaped prong with contacts on opposite sides.

The final iteration, which is pictured above, builds a house of cards on top of the buck converter. After regulating down to 12V he feeds the output into a “cigarette-lighter” style inverter to boost back to 110V AC. The hardware is housed inside of a scrapped charger for the batteries, with the appropriate 3-prong socket hanging out the back. We think it’s a nice touch to include LED feedback for the battery level.

We would like to hear your thoughts on this technique. Is there a better way that’s as easy and adaptive (you don’t have to alter the devices you’re powering) as this one?

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