DIY Single Pixel Digital Camera

January 21, 2015 by Brian Benchoff 46 Comments

[Artlav] wanted to build a digital camera, but CCDs are expensive and don’t respond well to all wavelengths of light. No problem, then, because with a photodiode, a few stepper motors, the obligatory Arduino, and a cardboard box, it’s pretty easy to make one from scratch.

The camera’s design is based on a camera obscura – a big box with a pinhole in one side. This is all a camera really needs as far as optics go, but then there’s the issue of digitizing the faint image projected onto the rear of the camera. That’s fine, just build a cartesian robot inside the box and throw a photodiode in there.

There are a few considerations when choosing a photodiode for a digital camera. Larger photodieodes have higher noise but lower resolution. [Artlav] has been experimenting with a few diodes, but his options are limited by export control restrictions.

Even with the right photodiode, amplifying the tiny amount of current – picoamps in some cases – is hard. The circuit is extremely sensitive to EMI, and it’s inside a box with stepper motors pulled from the scrap bin. It’s amazing this thing works at all.

Still, [Artlav] was able to get some very high resolution images across a huge range of wavelengths. He’s even getting a few images in mid-wave infrared, turning this homebrew digital camera into the slowest thermal imaging camera we’ve ever seen.

Open Source Haptics Kit Aims To Democratize Force Feedback

January 21, 2015 by Sonya Vasquez 27 Comments

If you’ve been keeping up with augmented and virtual reality news, you’ll remember that spacial haptic feedback devices aren’t groundbreaking new technology. You’ll also remember, however, that a professional system is notoriously expensive–on the order of several thousand dollars. Grad students [Jonas], [Michael], and [Jordi] and their professor [Eva-Lotta] form the design team aiming to bridge that hefty price gap by providing you with a design that you can build at home.

A quick terminology dive: a spacial haptic device is a physical manipulator that enables exploration of a virtual space through force feedback. A user grips the “manipulandum” (the handle) and moves it within the work area defined by the physical design of the device. Spacial Haptic Devices have been around for years and serve as excellent tools for telling their users (surgeons) what something (tumor) “feels like.”

In our case, this haptic device is a two-link, two-joint system grounded on a base station and providing force feedback with servo motors and tensioned wire ropes. The manipulator itself supports 3-degree-of-freedom movement of the end-effector (translations, but no rotations) which is tracked with encoders placed on all joints. To enable feedback, joints are engaged with cable-drive transmissions.

The design team isn’t new to iterative prototyping. Hailing from CS235, a Stanford course aimed to impart protoyping techniques to otherwise non-tinkerers, the designers have drawn numerous techniques from this course to deliver a fully functional and reproducible setup. In fact, it’s clear that the designers have a strong understanding of their system’s physics, and they capitalize on a few tricks that don’t immediately jump out to us as intuitive. For instance, rather than rigidly fixing their cable to the motor shaft, they simply wrap the cable around the shaft a mere 5 turns such that the force of friction greatly exceeds the threshold amount that would otherwise cause slipping. They also choose plywood–not necessarily because of its price–but more so because of its function as a stiff, layered composite that makes it ideal “lever arm material” for rigidly transferring forces.

For a full breakdown of their design, take a look at their conference paper (PDF) where they evaluate their design techniques and outline the forward kinematics. They’ve also provided a staggeringly comprehensive bill of materials (Google Spreadsheet). Finally, as justifiably open source hardware, they’ve packaged their control software and CAD models into a github repository so that you too can jump into the world of quality force feedback simulation without shelling out the twenty thousand dollars for a professional system.

[via the 2015 Tangible Embedded and Embodied Conference]

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3D Printed Camera Battery Emulator

January 21, 2015 by Rich Bremer 30 Comments

There are certainly battery hungry devices out there on the market and, unless you do some serious research before the purchase of said device, you really don’t know how it will perform. Needless to say, some of us get stuck with power hog device, and it seriously sucks because changing out batteries often is expensive and just plain annoying.

If you couldn’t tell, I am speaking from experience, my old Sony DSC-H5 camera works great with the exception of needing new batteries every hour. And if you get cheap batteries, the camera won’t even turn on! There’s a USB connector on the camera but it is only for transferring data and there is also no DC input jack. The entire situation is a totally bummer.

I’m happy (or disappointed) that I am not alone in the world. [Phil] wrote into the HaD tip line to tell us about his solution to this very problem. He has a Canon SD1000 camera and although the battery works fine he needs it to work at an altitude of 15km in order to take some sunrise photos. Cold weather testing (in the fridge freezer) showed that the battery isn’t going to cut the mustard for the hour-long flight. The rest of the balloon-lifted unit already has a battery pack and the plan would be to tap into that to power the camera. Unfortunately his camera, like mine, doesn’t have a DC input jack and can not be powered off the USB port.

[Phil] decided to make a 3D printed battery emulator. It sits in place of the stock battery and holds bare wire where the batteries terminals normally are. The other end of the wires are run out of the camera to a voltage regulator that converts the battery pack’s 6 volts down to the 3.9 that the camera needs.

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Home Made CNC Router Boasts Welded Steel Frame And Super Tidy Wire Management

January 21, 2015 by Rich Bremer 15 Comments

[Cooperman] had been poking around the ‘net checking out DIY CNC machines for a while. He wanted to build one. During his search, he noticed that there was a common thread amongst homemade machines; they were usually made from parts that were on hand or easily obtainable. He had some parts kicking around and decided to hop on the band wagon and build a CNC Router. What sets [Cooperman]’s project apart from the rest is that he apparently had some really nice components available in his parts bin. The machine is nicknamed ‘Tweakie‘ because it will never really be finished, there’s always something to tweak to make it better.

The foundation for Tweakie is a welded frame made from 25mm steel square tubing. A keen observer may point out that welding a frame may cause some distortion and warping. [Cooperman] thought of that too so he attached aluminum spacers to the steel frame and lapped them flat. After that, fully supported THK linear bearings were attached to the now-straight spacer surface. Both the X and Y axes have ball-screws to minimize backlash and are powered by NEMA23 stepper motors. The Z axis uses 16mm un-supported rods with pillow block linear bearings. Unlike the X and Y, the Z axis uses a trapezoidal lead screw and bronze nut. [Cooperman] plans on replacing this with a ball-screw in the future but didn’t have one on hand at the time of assembly.

Mach3 is the software being used to control the CNC Router. It communicates via parallel port with a 3-axis StepMaster motor driver board that can handle providing 24vdc to the stepper motors. All of the electronics are mounted neatly in an electrical cabinet mounted on the back of the machine. Overall, this is a super sturdy and accurate machine build. [Cooperman] has successfully cut wood, plastic and even aluminum!

Sigzig Data Loggers Ditch The Noise While Pimping The Case

January 21, 2015 by Mike Szczys 25 Comments

We ran into [Paul Allen] at CES. He was showing off Sigzig, a super-low noise data logger which his company is just rolling out.

A couple of years ago he worked on a standalone chemical sensor and had a few extra boards sitting around after the project was done. As any resourceful hacker will do, he reached for them as the closest and easiest solution when needing to log data as a quick test. It wasn’t for quite some time that he went back to try out commercially available loggers and found a problem in doing so.

The performance of off-the-shelf data loggers wasn’t doing it for [Paul’s] team. They kept having issues with the noise level found in the samples. Since he had been patching into the chemical sensor PCBs and getting better results, the impetus for a new product appeared.

The flagship 24-bit 8-channel Sigzig samples 0-5v with less than 1uV of noise. A less expensive 4-channel differential unit offers 18-bit with 10-12 uV of noise. They are targeting $199 and $399 price points for the two units. We asked about the sample rate in the video below. The smaller version shown here captures up to 240 samples per second. The big guy has the hardware potential to sample 30,000 times per second but ~~since the data is continuously streaming over USB~~ that rate is currently limited to much less.

Update: It has been pointed out in the comments that USB may not be the choke point for sample rate.

Remotely Controlling Automobiles Via Insecure Dongles

January 21, 2015 by Rick Osgood 56 Comments

Automobiles are getting smarter and smarter. Nowadays many vehicles run on a mostly drive-by-wire system, meaning that a majority of the controls are electronically controlled. We’re not just talking about the window or seat adjustment controls, but also the instrument cluster, steering, brakes, and accelerator. These systems can make the driving experience better, but they also introduce an interesting avenue of attack. If the entire car is controlled by a computer, then what if an attacker were to gain control of that computer? You may think that’s nothing to worry about, because an attacker would have no way to remotely access your vehicle’s computer system. It turns out this isn’t so hard after all. Two recent research projects have shown that some ODBII dongles are very susceptible to attack.

The first was an attack on a device called Zubie. Zubie is a dongle that you can purchase to plug into your vehicle’s ODBII diagnostic port. The device can monitor sensor data from your vehicle and them perform logging and reporting back to your smart phone. It also includes a built-in GPRS modem to connect back to the Zubie cloud. One of the first things the Argus Security research team noticed when dissecting the Zubie was that it included what appeared to be a diagnostic port inside the ODBII connector.

Online documentation showed the researchers that this was a +2.8V UART serial port. They were able to communicate over this port with a computer with minimal effort. Once connected, they were presented with an AT command interface with no authentication. Next, the team decompiled all of the Python pyo files to get the original scripts. After reading through these, they were able to reverse engineer the communication protocols used for communication between the Zubie and the cloud. One particularly interesting finding was that the device was open for firmware updates every time it checked in with the cloud.

The team then setup a rogue cellular tower to perform a man in the middle attack against the Zubie. This allowed them to control the DNS address associated with the Zubie cloud. The Zubie then connected to the team’s own server and downloaded a fake update crafted by the research team. This acted as a trojan horse, which allowed the team to control various aspects of the vehicle remotely via the cellular connection. Functions included tracking the vehicle’s location, unlocking hte doors, and manipulating the instrument cluster. All of this can be done from anywhere in the world as long as the vehicle has a cellular signal.

A separate but similar project was also recently discussed by [Corey Thuen] at the S4x15 security conference. He didn’t attack the Zubie, but it was a similar device. If you are a Progressive insurance customer, you may know that the company offers a device that monitors your driving habits via the ODBII port called SnapShot. In exchange for you providing this data, the company may offer you lower rates. This device also has a cellular modem to upload data back to Progressive.

After some research, [Thuen] found that there were multiple security flaws in Progressive’s tracker. For one, the firmware is neither signed nor validated. On top of that, the system does not authenticate to the cellular network, or even encrypt its Internet traffic. This leaves the system wide open for a man in the middle attack. In fact, [Thuen] mentions that the system can be hacked by using a rogue cellular radio tower, just like the researchers did with the Zubie. [Thuen] didn’t take his research this far, but he likely doesn’t have too in order to prove his point.

The first research team provided their findings to Zubie who have supposedly fixed some of the issues. Progressive has made a statement that they hadn’t heard anything from [Thuen], but they would be happy to listen to his findings. There are far more devices on the market that perform these same functions. These are just two examples that have very similar security flaws. With that in mind, it’s very likely that others have similar issues as well. Hopefully with findings like this made public, these companies will start to take security more seriously before it turns into a big problem.

[Thanks Ellery]

A Portable KIM-1

January 20, 2015 by Brian Benchoff 26 Comments

The KIM-1 was the first computer to use the 6502, a CPU that would later be found in the Apple, Ataris, Commodores, and the Nintendo Entertainment System. Being the first, the KIM-1 didn’t actually do a whole lot with only 1k of ROM and a bit more than 1k of RAM. This is great news for anyone with an Arduino; you can easily replicate an entire KIM-1, with a keypad and 7-segment display. That’s what [Scott] did, and he put it in an enclosure that would look right at home in a late 70s engineering lab.

The impetus for this build was [Scott]’s discovery of the KIM-Uno, a kit clone of the KIM-1 using an Arduino Pro Mini. The kit should arrive in a few weeks, so until then he decided to see if he could cobble one together with parts he had sitting around.

Inside a handheld industrial enclosure is an Arduino Uno, with a protoshield connecting the keypad and display. The display is an 11-digit, seven-segment display [Scott] picked up at a surplus shop, and the metal dome keypad came from a hamfest.

Getting the software working took a bit of work, but the most important parts are just modifications to the standard Arduino libraries.

Now that [Scott] has a KIM-1 replica, he can program this virtual 6502 one hex digit at a time, run Microchess, or use the entire thing as a programmable calculator.