“Yell To Press B” Mod Makes N64 Controller Worse

November 25, 2018 by Donald Papp 8 Comments

There’s probably no reason anyone would actually desire a mod like this. Well, no good reason. But [William Osman] had been pondering what it would be like to play some classic games with inputs other than buttons, and decided to make an audio sensor responsible for pressing the B button on an old N64 controller. This “Yell To Press B” mod was also something unique to show his hosts when he visited the YouTube video game aficionados, [Game Grumps].

[William] acknowledges that the build is a bit of a hack job, but the project page does a good job of documenting his build process and covering the kinds of decisions involved in interfacing to a separate piece of hardware. After all, most budding hackers have sooner or later asked themselves “how do I make my gadget press a button on this other thing?” [William] ends up using a small relay to close the connection between the traces for the B button when triggered by a microphone module, but he points out that it should be possible to do a non-destructive version of the mod. Examples exist of reading the N64 controller’s state with an Arduino, which could form the basis of a man-in-the-middle approach of “Yell To Press B” (or anything else) instead of soldering to the button contacts. A video is embedded below, in which you can watch people struggle to cope with the bizarre mod.

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Quick Face Recognition With An FPGA

November 25, 2018 by Inderpreet Singh 8 Comments

It’s the 21st century, and according to a lot of sci-fi movies we should have perfected AI by now, right? Well we are getting there, and this project from a group of Cornell University students titled, “FPGA kNN Recognition” is a graceful attempt at facial recognition.

For the uninitiated, the K-nearest neighbors or kNN Algorithm is a very simple classification algorithm that uses similarities between given sets of data and a data point being examined to predict where the said data point belongs. In this project, the authors use a camera to take an image and then save its histogram instead of the entire image. To train the network, the camera is made to take mug-shots of sorts and create a database of histograms that are tagged to be for the same face. This process is repeated for a number of faces and this is shown as a relatively quick process in the accompanying video.

The process of classification or ‘guess who’, takes an image from the camera and compares it with all the faces already stored. The system selects the one with the highest similarity and the results claimed are pretty fantastic, though that is not the brilliant part. The implementation is done using an FPGA which means that the whole process has been pipe-lined to reduce computational time. This makes the project worth a look especially for people looking into FPGA based development. There is a hardware implementation of a k-distance calculator, sorting and selector. Be sure to read through the text for the sorting algorithm as we found it quite interesting.

Arduino recently released the Arduino MKR4000 board which has an FPGA, and there are many opensource boards out there in the wild that you can easily get started with today. We hope to see some of these in conference badges in the upcoming years.

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Hackaday Links: November 25, 2018

November 25, 2018 by Brian Benchoff 20 Comments

Bad Obsession Motorsport have been stuffing the engine and suspension from a 4WD Celica into an old Mini since forever. It is a wonderful homage to Police Squad and some of the best machining and fabrication you’ll see on YouTube. The latest episode tackled the electrical system and how to drive an alternator in an extremely cramped engine bay. The solution was a strange flex-shaft confabulation, and now the Bad Obsession Motorsport guys have a video on how they attached an alternator to a car where no alternator should go. It’s forty minutes of machining, go watch it.

Last Friday was Black Friday, and that means it’s time to CONSUME CONSUME CONSUME. Tindie’s having a sale right now, so check that out.

I’m the future of autonomous flight! This week, I got a market research survey in my email from Uber, wanting me to give my thoughts on autonomous ridesharing VTOL aircraft. Uber’s current plan for ridesharing small aircraft involves buying whatever Embraer comes up with (Uber is not developing their own aircraft), not having pilots (this will never get past the FAA), and turning a random parking lot in LA into the busiest airport in the world (by aircraft movements, which again is something that will never get past the FAA). Needless to say, this is criminally dumb, and I’m more than happy to give my thoughts. Below are the relevant screencaps of the survey:

The crux of this survey is basic market research; how much would I pay for a VTOL ride sharing service versus buying a new (autonomous) car versus using an autonomous Uber. You’ve also got a Likert scale thingy asking me if I’m comfortable flying in a battery-powered aircraft. Protip: I highly doubt anyone given this survey has flown in a battery-powered aircraft. Proprotip: the easiest way to screw up the scoring for a Likert scale is to answer ‘1’ for the first question, ‘2’ for the second, etc., and wrap back around to ‘1’ for the sixth question.

Don’t worry, though: I answered all the questions truthfully, but Uber Air will never happen. The FAA won’t let this one fly, and no company will ever carry passengers without a licensed pilot on board.

Solar-Powered IoT Sensor Saves Wine Batch From Overheating

November 25, 2018 by Donald Papp 4 Comments

Making wine isn’t just about following a recipe, it’s a chemical process that needs to be monitored and managed for best results. The larger the batch, the more painful it is to have something go wrong. This means that the stakes are high for small vineyards such as the family one [Mare] works with, which have insufficient resources to afford high-end equipment yet have the same needs as larger winemakers. The most useful thing to monitor is the temperature profile of the fermentation process, and [Mare] created an exceptional IoT system to do that using LoRa wireless and solar power.

It’s not enough just to measure temperature of the fermenting liquid; viewing how the temperature changes over time is critical to understanding the process and spotting any trouble. [Mare] originally used a Raspberry Pi, I2C temperature sensor, and a Wi-Fi connection to a database to do the monitoring. This was a success, but it was also overkill. To improve the system, the Raspberry Pi was replaced with a LoRaDunchy board, an STM-based module of [Mare]’s own design which is pin-compatible with the Arduino Nano. It includes a battery charger, power management, and LoRa wireless communication. Adding a solar cell and lithium-polymer battery was all it took to figuratively cut the power cord.

Sensing the temperature of fermentation is done by sealing the temperature sensor into a thin aluminum tube, and lowering that into the vat. There it remains, with the LoRaDunchy board periodically waking up to read the sensor and report the tempurature over LoRa before going back to sleep, all the while sipping power from the battery which in turn gets recharged with solar power.

It’s an elegant system that has already paid off. A 500 litre vat of wine generated an alarm when the temperature rose above 24 Celsius for 10 minutes. An email alert allowed the owner to begin mixing the solution and add ice water to put the brakes on the runaway reaction. The temperature dropped and slow fermentation resumed, thanks to the twin powers of gathering the right data, then doing something meaningful with it.

Vineyards and LoRa have joined forces before, for example in the Vinduino project which aims to enable water-smart farming. If you’re unfamiliar with LoRa in general, the LoRa on the ESP32 project page contains a good primer, and if the antenna on the module shown here looks familiar to you it’s because we recently featured [Mare]’s guide on making DIY LoRa antennas from salvaged wire.

Already Impressive CNC Router Gets An Extra Axis

November 25, 2018 by Dan Maloney 6 Comments

The type of CNC machine within the financial reach of most DIYers is generally a three-axis affair, with a modest work envelope and a spindle that never quite seems powerful enough. That’s not to say that we don’t covet such a machine for our own shop of course, but comparing small machines with the “big boy” five-axis tools might leave the home-gamer feeling a tad inadequate.

Luckily, there’s a fix that won’t necessarily break the bank: adding a fourth axis to your CNC router. [This Old Tony] tore into his CNC router – a build we’ve featured before and greatly admire – to add a machine spindle that lets him work with the machine much as if it was a CNC lathe. The first video below covers the mechanical part of the build, which involves welding and machining a sturdy assembly to hold a spindle connecting a four-jaw chuck to a Lexium MDrive, a stepper motor with integrated driver and feedback that makes it act more like a servo. [Old Tony] covered integrating the drive into Mach4 in a previous video.

The assembled machine spindle is a beefy looking affair that can smoothly ramp up to 3000 rpm and has decent enough holding torque to allow it to act as an indexing head in addition to a lathe. The second video below shows some tests turning aluminum and steel; we were surprised by how aggressive the cuts can be before stalling the spindle.

No, it’s not a Tormach or Haas or even a Pocket NC, but it’s a great addition to an already capable machine, and we’re looking forward to what [Old Tony] cranks out with it.

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3D Printed V8 Engine Uses Solenoids

November 25, 2018 by Al Williams 17 Comments

Normally when you think of a V8 engine you think of pistons driven by exploding fuel, pushing a crankshaft. [Miller’s Planet’s] version doesn’t use pistons, instead it uses solenoids along with a 3D printed crankshaft. The finished product would make a great science project or classroom demonstration of how a crankshaft converts a reciprocal linear motion into a rotary motion.

There are a lot of 3D printed parts and the links are in the post. A lot of the video (see below) is filmed in the wordless-workshop style with just a few text overlays to explain what is happening. But towards the middle, you’ll hear an explanation of how a solenoid produces force. The real payoff though is at the end, when you get to watch the contraption in motion.

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DIY Ovalia Chair Serves Your Futuristic Fantasies

November 25, 2018 by Lewin Day 16 Comments

The 1960s were a heady time, with both society and the language of design undergoing rapid changes over a short period. Back in 1968, Henrik Thor-Larsen exhibited his Ovalia egg chair for the first time, at the Scandinavian Furniture Fair. With original examples now antiques, and with even replicas being prohibitively expensive, it might just be worth considering building your own if you need to have one. Thankfully, [Talon Pascal] leads the way.

It’s a replica that’s built with accessible DIY tools and techniques. The frame is built up from plywood parts, cut out with a jigsaw. These are then assembled with glue and screws, forming two halves of the full-sized egg assembly. The exterior is then covered with thin strips of wood, as opposed to the fiberglass construction of the original. This is smoothed out with a judicious application of wood putty and plenty of sanding. The interior is then lined with foam before the chair is upholstered with red fabric. We’re not sure exactly how the trim ring is fitted, but it gives the chair a nice clean finished edge and rounds out the project nicely. There are even embedded speakers so you can chill out with some tunes in your ovaloid sanctuary.

It just goes to show that there’s value in the old adage – if you can’t buy it, build it! Perhaps, however, you’re outfitting the office – in which case, would something from the Porsche range suffice?