Making a Solar-Cell Tester With Mecrisp-Stellaris Forth

In the last two articles on Forth, I’ve ranted about how it’s beautiful but strange, and then gotten you set up on a basic system and blinked some LEDs. And while I’ve pointed you at the multitasker, we haven’t made much real use of it yet. Getting started on a Forth system like this is about half the battle. Working inside the microcontroller is different from compiling for the microcontroller, and figuring out the workflow, how to approach problems, and where the useful resources are isn’t necessarily obvious. Plus, there’s some wonderful features of Mecrisp-Stellaris Forth that you might not notice until you’ve hacked on the system for a while.

Ideally, you’d peek over the shoulder of someone doing their thing, and you’d see some of how they work. That’s the aim of this piece. If you’ve already flashed in our version of Mecrisp-Stellaris-plus-Embello, you’re ready to follow along. If not, go back and do your homework real quick. We’ll still be here when you’re done. A lot of this article will be very specific to the Mecrisp-Stellaris flavor of Forth, but given that it runs on tons of ARM chips out there, this isn’t a bad place to be.

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Hack Your Own Samsung TV With The CIA’s Weeping Angel Exploit

[Wikileaks] has just published the CIA’s engineering notes for Weeping Angel Samsung TV Exploit. This dump includes information for field agents on how to exploit the Samsung’s F-series TVs, turning them into remotely controlled spy microphones that can send audio back to their HQ.

An attacker needs physical access to exploit the Smart TV, because they need to insert a USB drive and press keys on the remote to update the firmware, so this isn’t something that you’re likely to suffer personally. The exploit works by pretending to turn off the TV when the user puts the TV into standby. In reality, it’s sitting there recording all the audio it can, and then sending it back to the attacker once it comes out of “fake off mode”.

It is still unclear if this type of vulnerability could be fully patched without a product recall, although firmware version 1118+ eliminates the USB installation method.

The hack comes along with a few bugs that most people probably wouldn’t notice, but we are willing to bet that your average Hackaday reader would. For instance, a blue LED stays on during “fake off mode” and the Samsung and SmartHub logos don’t appear when you turn the TV back on. The leaked document is from 2014, though, so maybe they’ve “fixed” them by now.

Do you own a Samsung F-series TV? If you do, we wouldn’t worry too much about it unless you are tailed by spies on a regular basis. Don’t trust the TV repairman!

Juicero: A Lesson On When To Engineer Less

Ben Einstein, a product designer and founder at Bolt, a hardware-based VC, recently got his hands on a Juicero press. This desktop juice press that only works with proprietary pouches filled with chopped fruits and vegetables is currently bandied in the tech press as evidence Silicon Valley has gone mad, there is no future in building hardware, and the Internet of Things is a pox on civilization. Hey, at least they got the last one right.

This iFixit-style tear down digs into the Juicero mixer in all its gory details. It’s beautiful, it’s a marvel of technology, and given the engineering that went into this machine, it was doomed to fail. Not because it didn’t accomplish the task at hand, but because it does so with a level of engineering overkill that’s delightful to look at but devastating to the production cost.

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VR Mech’s Missing Link: The Phone in Your Pocket

In the process of making a homemade Mech Combat game that features robot-like piloted tanks capable of turning the cockpit independent of the direction of movement, [Florian] realized that while the concept was intuitive to humans, implementing it in a VR game had challenges. In short, when the body perceives movement but doesn’t feel the expected acceleration and momentum, motion sickness can result. A cockpit view that changes independently of forward motion exacerbates the issue.

To address this, [Florian] wanted to use a swivel chair to represent turning the Mech’s “hips”. This would control direction of travel and help provide important physical feedback. He was considering a hardware encoder for the chair when he realized he already had one in his pocket: his iPhone.

By making an HTML page that accesses the smartphone’s Orientation API, no app install was needed to send the phone’s orientation to his game via a WebSocket in Unity. He physically swivels his chair to steer and is free to look around using the VR headset, separate from the direction of travel. Want to try it for yourself? Get it from [Florian]’s GitHub repository.

A video is embedded below, but if you’re interested in details be sure to also check out [Florian]’s summary of insights and methods for avoiding motion sickness in a VR Mech cockpit.

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Get Up Close to your Soldering with a Pi Zero Microscope

Do your Mark 1 Eyeballs no longer hold their own when it comes to fine work close up? Soldering can be a literal pain under such conditions, and even for the Elf-eyed among us, dealing with pads at a 0.4-mm pitch is probably best tackled with a little optical assistance. When the times comes for a little help, consider building a soldering microscope from a Pi Zero and a few bits and bobs from around the shop.

Affordable commercial soldering scopes aren’t terribly hard to come by, but [magkopian] decided to roll his own by taking advantage of the streaming capabilities of the Raspberry Pi platform, not to mention its affordability. This is a really simple hack — nothing is 3D-printed or custom milled. The stage base is a simple aluminum project box for heat resistance and extra weight, and the arm is a cheap plastic dial caliper. The PiCam is mounted to the sliding jaw of the caliper on a scrap of plastic ruler. The lens assembly of the camera needs to be hacked a little to change the focal length to work within 10 centimeters or so; alternatively, you could splurge and get a camera module with an adjustable lens. The Pi is set up for streaming, and your work area is presented in glorious, lag-free HDMI video.

Is [magkopian]’s scope going to give you the depth perception of a stereo microscope? Of course not. But for most jobs, it’ll probably be enough, and the fact that it can be built on the cheap makes it a great hack in our book.

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Old Part Day: Voltage Controlled Filters

For thirty years, the classic synths of the late 70s and early 80s could not be reproduced. Part of the reason for this is market forces — the synth heads of the 80s didn’t want last year’s gear. The other part for the impossibility to build new versions of these synths was the lack of parts. Synths such as the Prophet 5, Fairlight CMI, and Korg Mono/Poly relied on voltage controlled filter ICs — the SSM2044 — that you can’t buy new anymore. If you can source a used one, be prepared to pay $30. New old stock costs about $100.

Now, these chips are being remade. A new hardware revision for this voltage controlled filter has been taped out by the original hardware designer, and these chips are being produced in huge quantities. Instead of $100 for a new old stock chip, this chip will cost about $1.60 in 1000 unit quantities.

The list of synths and music boxes sporting an SSM2044 reads like a Who’s Who of classic electronic music machines. E-Mu Drumulators, Korg polyphonic synths, Crumars, and even a Doepfer module use this chip in the filter section. The new chip — the SSI2144 — supposedly provides the same classic tone but adds a few improvements such as improved pin layouts, an SSOP package, and more consistent operation from device to device.

This news follows the somewhat recent trend of chip fabs digging into classic analog designs of the 70s, realizing the chips are being sold for big bucks on eBay, and releasing it makes sense to spin up a new production line. Last year, the Curtis CEM3340 voltage controlled oscillator was rereleased, giving the Oberheim OB, Roland SH and Jupiter, and the Memory Moog a new lease on life. These chips aren’t only meant to repair broken, vintage equipment; there are a few builders out there who are making new devices with these rereleased classic synths.

 

Look at me with your Special Animatronic Eyes

Animatronics for movies is often about making something that works and is reliable in the short term. It doesn’t have to be pretty, it doesn’t have to last forever. [Corporate Sellout]  shows us the minimalist approach to building animatronics with this pair of special eyes.  These eyes move in both the pan and tilt. Usually, that means a gimbal style mount. Not in this case. The mechanical assembly consists of with popsicle sticks, ping-pong balls, film canisters and dental floss.

The frame for the eyes is made of simple popsicle sticks hot glued together. The eyes themselves are simple ping-pong balls. Arduino powered servos control the movement. The servos are connected to dental floss in a cable arrangement known as a pull-pull system. As each servo moves, one side of the arm pulls on a cable, while the other provides enough slack for the ping-pong ball to move.

Mounting the ping-pong balls is the genius part of this build. They simply sit in the open end of a couple of film canisters. the tension from the dental floss holds everything together. We’re sure it was a finicky setup to build, but once working, it’s reliable. Only a glue joint failure or stretch in the dental floss could cause issues.

There are plenty of approaches to Animatronic eyes. Check out the eyes in this Stargate Horus helmet, which just won our Sci-Fi contest. More recently we saw Gawkerbot, which uses a CD-ROM drive to provide motion for a creepy robot’s eyes.

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