SNES Portable Leverages Flash Cart For More Games

January 25, 2019 by 12 Comments

Handheld consoles have to make a lot of design choices that their TV connected brethren don’t have to worry about. Battery life is important, as is screen visibility, and the games can’t be too bulky or unwieldy if you’re going to be carrying them around all day. [Chris] is no stranger to building handheld versions of home consoles, and took a few of these lessons on board in his latest portable SNES build.

The motherboard was provided by a SNES Jr., a lightweight, compact model released towards the end of the console’s reign. This was small enough that it required no trimming, however [Chris] elected to replace the inefficient 7805 with a more modern switching regulator. The case was 3D printed on a typical FDM setup, while the buttons were produced on a Form 2 for better dimensional accuracy and surface finish.

The flash cart PCB is permanently wired to the motherboard.

The real party piece, however, is the use of an SD2SNES flash cart. This allows a huge variety of ROMs to be loaded onto a single SD card, and played on the original console hardware. This is particularly useful in a portable build, as it becomes possible to carry all the games you could want, rather than having to juggle several full-sized SNES cartridges. The SD2SNES is wired in place permanently inside the console, with an impressive number of patch wires between the motherboard and the cartridge PCB. Despite the long lead length, [Chris] reports no issues with the connection.

There are some limitations – the flash cart doesn’t work properly for games using extra chips on the cartridge, like the SuperFX in Star Fox, for example. Despite this, it’s an excellent, high quality build that we’re sure is a lot of fun to play out and about.

We’ve seen [Chris]’s work before – this portable N64 is a particularly nice example. Video after the break.

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Robot Can’t Take Its Eyes Off The Bottle

January 25, 2019 by 18 Comments

Robots, as we currently understand them, tend to run on electricity. Only in the fantastical world of Futurama do robots seek out alcohol as both a source of fuel and recreation. That is, until [Les Wright] and his beer seeking robot came along. (YouTube, video after the break.)

A Raspberry Pi 3 provides the brains, with an Intel Neural Compute stick plugged in as an accelerator for neural network tasks. This hardware, combined with the OpenCV image detection software, enable the tracked robot to identify objects and track their position accordingly.

That a beer bottle was chosen is merely an amusing aside – the software can readily identify many different object categories. [Les] has also implemented a search feature, in which the robot will scan the room until a target bottle is identified. The required software and scripts are available on GitHub for your perusal.

Over the past few years, we’ve seen an explosion in accelerator hardware for deep learning and neural network computation. This is, of course, particularly useful for robotics applications where a link to cloud services isn’t practical. We look forward to seeing further development in this field – particularly once the robots are able to open the fridge, identify the beer, and deliver it to the couch in one fell swoop. The future will be glorious!

 

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Silent Stepper Drive Makes A Nicer Watch Winder

January 24, 2019 by 12 Comments

Mechanical watches are great in that they never need batteries, but they are simultaneously less than great in that they will lose time if not worn or otherwise regularly agitated. The ridiculous solution to this is the watch winder, which automatically rotates your mechanical watches for you, while you’re not wearing them. This is probably the item you’ll miss the least once the apocalypse hits. [Kristopher] wanted a nice quiet watch winder for his bedside table, but existing solutions were either too loud or too expensive. As is often the case, hacking ensued.

[Kristopher] had decided that starting from scratch was too much hassle. The cheaper watch winders on the market had acceptable quality enclosures, but were simply too loud. [Kristopher] sourced a $40 unit from Amazon, and proceeded to gut the drivetrain. This was replaced with a Sparkfun stepper motor and a Trinamic SilentStepStick – an advanced stepper motor driver that uses several techniques to reduce noise during operation.

An Arduino Nano was substituted as the brains of the operation, communicating with the stepper driver and allowing the winder to be configured for different wind rates. [Kristopher] reports that the device operates near-silently, and the total cost came in well below that of a high-end luxury winder.

Mechanical watches don’t always get a lot of attention these days, but we’ve seen one built from the ground up before. As always, with tips – send ’em if you got ’em.

Can You Trust Your C Compiler?

January 24, 2019 by 57 Comments

If you are writing a hello world program, you probably aren’t too concerned about how the compiler translates your source code to machine code. However, if your code runs on something that people’s lives depend on, you will want to be a bit pickier and use something like the COMPCERT compiler.  It’s a formally verified compiler, meaning there is a mathematical proof that what you write in C will be correctly translated to machine code. The compiler can generate for PowerPC, ARM, RISC-V, and x86, accepting a subset of ISO C 99 with a few extensions. While it doesn’t produce code that runs as fast as gcc, you can be sure the generated code will do what you asked it to do.

Of course, this still provides no assurance that your code will work. It just means that if you write something such as “x=0;” the generated code will set x to zero and will not do anything else. You can apply formal methods to verify your source code and be assured that the compiler doesn’t introduce possible failures. Cases where code like “x=0;” does extra things or incorrect things are very hard to figure out because the source code is correct and an examination of the generated code would be necessary to find the compiler’s code generation bug.

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Reaction Wheels Almost Control This Unusual Drone

January 24, 2019 by 11 Comments

When you think about all the forces that have to be balanced to keep a drone stable, it’s a wonder that the contraptions stay in the air at all. And when the only option for producing those forces is blowing around more or less air it’s natural to start looking for other, perhaps better ways to achieve flight control.

Taking a cue from the spacecraft industry, [Tom Stanton] decided to explore reaction wheels for controlling drones. The idea is simple – put a pair of relatively massive motorized wheels at right angles to each other on a drone, and use the forces they produce when they accelerate to control the drone’s pitch and roll. [Tom]’s video below gives a long and clear explanation of the physics involved before getting to the build, which results in an ungainly craft a little reminiscent of a lunar lander. The drone actually manages a few short, somewhat stable flights, but in general the reaction wheels don’t seem to be up to the task. [Tom] chalks this up to the fact that he’s using the current draw of each reaction wheel motor as a measure of its torque, which is not exactly correct for all situations. He suggests that motors with encoders might do a better job, but by the end of the video the little drone isn’t exactly in shape for continued experimentation.

Of course, dodgy reaction wheels don’t only cause problems with drones. They can also be a problem for spacecraft when the Sun gets fussy too.

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Solar-Powered OpenWRT Router For Mobile Privacy

January 24, 2019 by 25 Comments

Let’s not pretend we aren’t all guilty of it: at some point we’ve all connected to a public WiFi network to check our email or log into some site or service. We know the risks, we know better. But in a weak moment we can let the convenience of that public network get the better of us. What if you had a small secure router that you could use as an encrypted VPN endpoint, allowing you to connect to those enticing public networks while keeping your traffic secure? That’s precisely what [David] had in mind when he built this pint-sized solar-powered OpenWRT router.

At the heart of this gadget is the TP-Link TL-MR3020, a tiny OpenWRT-compatible router that’s no stranger to the pages of Hackaday. Its small size and low cost have made it a natural choice for a wide array of projects, so it’s little surprise that [David] gravitated towards it. But simply getting OpenWRT installed on the MR3020 and configuring OpenVPN doesn’t exactly grant you entrance into the Hackaday Pantheon, so obviously there’s a bit more to the story.

For one, [David] didn’t like the idea of a USB flash drive hanging out of the side of his router. Since the flash drive would essentially be a permanent part of the router, as it is being used to expand the rather meager internal storage of the MR3020 he decided to wack the USB end off the flash drive and solder it directly to the router’s PCB. This gave him a much cleaner looking package, but it still wasn’t as portable as he’d like.

He decided to order a solar-charged USB power bank to become the new home of his hacked MR3020. He kept the solar panel and charge controller from the original gadget, and after some researched settled on a pair of LG-HG2 3000 mAh batteries as the power source. [David] went through a few charge and discharge cycles making sure everything worked as expected before buttoning up the case. In the future he says he might transplant the electronics into a 3D printed case, but for now he’s pretty pleased with the results.

If you’d like to try your hand at hacking these popular micro routers, you’ll need to start with an OpenWRT firmware. After you’ve got a full blown Linux distro running on this little fellow, the only limitation is your own imagination.

Samy Kamkar’s LED Balloon Network

January 24, 2019 by 8 Comments

Writing this in the frigid darkness of a Northern Hemisphere January evening, I have to admit to more than a little envy of Samy Kamkar and his friends. One of their summer events is a private party at a secluded campground somewhere that looks quite warm, which from here seems mighty attractive.

Samy wanted to provide a spectacle for his friends. What he came up with is glowing orbs; LED balloons that would float above the campsite and wow his friends with their pretty synchronised illumination. Thus an adventure in wireless communications, lighter-than-air flammable gasses versus electronics weight calculations, and code optimization began, the details of which were shared in Samy Kamkar’s 2018 Hackaday Superconference talk embedded below.

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