Fail Of The Week: How Not To Electric Vehicle

December 3, 2018 by Dan Maloney 92 Comments

If you ever doubt the potential for catastrophe that mucking about with electric vehicles can present, check out the video below. It shows what can happen to a couple of Tesla battery modules when due regard to safety precautions isn’t paid.

The video comes to us by way of [Rich], a gearhead with a thing for Teslas. He clearly knows his way around the EV world, having rebuilt a flood-soaked Tesla, and aspires to open an EV repair shop. The disaster stems from a novelty vehicle he and friend [Lee] bought as a side project. The car was apparently once a Disney prop car, used in parades with the “Mr. Toad’s Wild Ride” theme. It was powered by six 6-volt golf cart batteries, which let it maintain a stately, safe pace on a crowded parade route. [Rich] et al would have none of that, and decided to plop a pair of 444-cell Tesla modules into it. The reduced weight and increased voltage made it a real neck-snapper, but the team unwisely left any semblance of battery management out of the build.

You can guess what happened next, or spin up to the 3:00 mark in the video to watch the security camera mayhem. It’s not clear what started the fire, but the modules started cooking off batteries like roman candles. Quick action got it pushed outside to await the fire department, but the car was a total loss long before they showed up. Luckily no other cars in the garage were damaged, nor were there any injuries – not that the car didn’t try to take someone out, including putting a flaming round into [Lee]’s chest and one into the firetruck’s windshield.

[Rich] clearly knew he was literally playing with fire, and paid the price. The lesson here is to respect the power of these beefy batteries, even when you’re just fooling around.

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Hackaday Links: December 2, 2018

December 2, 2018 by Brian Benchoff 15 Comments

CircuitPython is becoming a thing! CircuitPython was originally developed from MicroPython and ported to various ARM boards by Adafruit. Now, SparkFun is shipping their own CircuitPython board based on the nRF52840, giving this board an ARM Cortex-M4 and a Bluetooth radio.

You like contests, right? You like circuit boards too, right? Hackster.io now has a BadgeLove contest going on to create the Blinkiest Badge on Earth. Yes, this is a #badgelife contest, with the goal of demonstrating how much you can do in a single circuit badge. Prizes include a trip to San Francisco, a badass drone, a skateboard, a t-shirt, or socks. YES, THERE ARE SOCKS.

We have a date for the Vintage Computer Festival Pacific Northwest 2019. It’s going down March 23 and 24 at the Living Computers Museum in Seattle. The call for exhibitors is now open so head over and check it out. So far the tentative list of exhibits and presenters include Attack of the SPARC Clones, and I must mention that SPARC systems are showing up on eBay with much higher frequency lately. I have no idea why.

Need another con? How about a KiCAD con? The inaugural conference for KiCAD users is happening next April in Chicago and the call for talk proposals just opened up. The con focuses on topics like using KiCAD in a manufacturing setting, what’s going on ‘under the hood’ of KiCAD, and how to use KiCAD to make an advanced product.

Spanish police have stopped a homemade scooter. Someone, apparently, was tearing around a public road in Galacia on a homemade scooter. From the single picture, we’re going to say ‘not bad.’ It’s a gas-powered weed wacker mounted to a homemade frame.

Every year, in December, we take a look back at what Hackaday has accomplished in the past twelve months. Sure, we gave out hundreds of thousands of dollars in awards in the Hackaday Prize, and yes, we’ve pushed our coverage of tech advancements into weird, uncharted, but awesome territory. Our biggest accomplishment, though, is always how many readers we reach. This year, we had a slight fall-off in our readership in the Democratic People’s Republic of North Korea. We’re down from 156 views in 2017 to 75 views this year. While the year isn’t over, we don’t expect that number to change much. What was the cause of this drop-off? We’re not quite sure. Only time will tell, and we’re looking forward to serving fresh hacks every day to the DPRK in 2019.

Retrotechtacular: Some Of The Last CRTs From The Factory Floor

November 30, 2018 by Drew Littrell 41 Comments

It seems crazy having to explain what a piece of technology was like to someone who is barely fifteen years your junior, but yet we have reached that point when it comes to CRTs. There may still be remnants of CRT televisions and monitors left out in the wild, however, the chances that a kid preparing to enter high school has encountered one is slim. While there may be no substitute for the real thing, there is this raw video from [Glenn] who shared his tour of the Sony Trinitron assembly line in the early 2000s.

Sony Electronics’ cathode ray tube manufacturing facility was located alongside headquarters in Rancho Bernado, CA. The facility was shuttered in 2006 when Sony transitioned wholly onto digital displays like the flat-panel LCD line of Bravia televisions. [Glenn]’s video shows that the manufacturing process was almost entirely automated from end to end. A point that was made even more clear with the distinct lack of human beings in the video.

The Trinitron line of televisions first appeared in 1968. At a time where most manufacturer’s were offering black and white picture tubes, Sony’s Trinitron line was in color. That name carried through until the end when it was retired alongside tube televisions themselves. Sony’s focus on technological innovation (and proprietary media formats) made them a giant in the world of consumer electronics for over forty years in the United States, but in the transition to a digital world saw them seeding market share to their competitors.

A quick word of warning as the video below was shot directly on Sony’s factory floor so the machinery is quite loud. Viewers may want to reduce the volume prior to pressing play.

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Building Portable Linux Devices: Never Been Easier, But Still Hard

November 30, 2018 by Jenny List 35 Comments

We live in a Golden Age of single-board computers. There was a time when a portable computer that was any good was a relatively rare and expensive device, certainly not something you could expect to replicate for yourself. A Psion, or later a Palm or perhaps a WinCE device would have been a lot more than an impulse purchase, and could not easily have been replicated using the components then available to the experimenter.

Thanks to spin-offs from technology developed for set-top boxes and mobile phones we can now buy any one of a pile of different boards that have almost equivalent power to a desktop computer. The experimenter can leverage that computing power to create their own small portables. Zerophone creator Arsenijs Picugins spoke about the tricky parts of designing a LInux portable at the recent Hackaday Superconference. You’ll find his talk below the break, which makes for a fascinating primer for those tempted to walk in his footsteps.

Minor Details of Portables are the Majority of the Build

In theory, it’s pretty easy to use one of these boards to make a portable computer. Take one of the smaller members of the Raspberry Pi or Beaglebone families, add a battery and a display, and away you go. But as always the devil is in the detail, and for a truly successful build there are a wealth of variables to attend to.

In his talk, Arsenijs takes us through the challenges of power supplies, connectors, and interfaces. In particular there is considerable challenge to running an SBC from a battery small enough to be portable, as efficiency concerns and the ability to easily recharge make for a critical set of choices. Then we learn of another pitfall, that of using USB as a default interface. Power loss in converting 5V to 3.3V that is inconsequential for a desktop computer is a battery-killer in a small device, so we’re pointed at the array of alternatives.

Zerophone screen menu [via @ZeroPhoneOSHW]

Screen Size is a Tricky Spec to Settle

If you’ve been tempted by one of those cheap Raspberry Pi touch screens, you’ll certainly understand that while a full desktop on a screen the size of a playing card looks cool, the reality is almost unusable. Your device will require a user interface that fits its form factor, which from his experience, Arsenijs suggests is best achieved through the medium of buttons rather than a touchscreen on smaller screens. There are a variety of UI and display libraries he introduces us to which make the whole process significantly easier.

Arsenijs’ Zerophone Raspberry Pi smartphone was a finalist in the 2017 Hackaday Prize, and remains an exemplary portable project from which many others can gain inspiration. We are privileged that he was able to bring his experience to speak at the Superconference, and his talk makes for a fascinating watch.

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Packing Decimal Numbers Easily

November 30, 2018 by Al Williams 12 Comments

While desktop computers have tons of computing power and storage, some small CPUs don’t have a lot of space to store things. What’s more is some CPUs don’t do multiplication and division very well. Same can be said for FPGAs. So suppose we are going to grab a bunch of three-digit decimal numbers from, say, a serial port. We want to store as many as we can, and we don’t want to do a lot of math because we can’t, it is slow, or perhaps it keeps our processor awake longer and we want to sleep to conserve power. We want a way to pack the numbers as close to the theoretical maximum as we can but with little or no math.

The simple approach is to store the numbers as ASCII. Great for processing since they are probably in ASCII already. If they aren’t, you just add 30 hex to each digit and you are done. That’s awful for storage space, though, since we can store 999 in 10 bits if it were binary and now we are using 24 bits! Storing in binary isn’t a good option, if you play by our rules, by the way. You need to multiply by 10 and 100 (or 10 twice) to get the encoding. Granted, you can change that to two shifts and an add (8x+2x=10x) but there’s no easy way to do the division you’ll have to do for the decode.

Of course, there’s no reason we can’t just store decimal digits. That’s call binary coded decimal or BCD and that has some advantages, too. It is pretty easy to do math on BCD numbers and you don’t get rounding problems. Some CPUs even have specific instructions for BCD manipulation. However, three digits will require 12 bits. That’s better than 24, we agree. But it isn’t as good as that theoretical maximum. After all, if you think about it, you could store 16 distinct codes in 4 bits, and we are storing only 10, so that 6 positions lost. Multiply that by 3 and you are wasting 18 codes.

But there is a way to hit that ten-bit target without doing any math. Its called DPD or densely packed decimal. You can convert three decimal digits into ten bits and then back again with no real math at all. You could implement it with a small lookup table or just do some very simple multiplexer-style logic which means it is cheap and easy to implement in software or onboard an FPGA.

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Katrina Nguyen Automates Her Mice

November 29, 2018 by Dan Maloney 5 Comments

When embarking on a career in the life sciences, it seems like the choice of which model organism to study has more than a little to do with how it fits into the researcher’s life. I once had a professor who studied lobsters, ostensibly because they are a great model for many questions in cell biology; in actuality, he just really liked to eat lobster. Another colleague I worked with studied salt transport in shark rectal glands, not because he particularly liked harvesting said glands — makes the sharks a tad grumpy — but because he really liked spending each summer on the beach.

Not everyone gets to pick a fun or delicious model organism, though, and most biologists have had to deal with the rats and mice at some point. It’s hard to believe how needy these creatures can be in terms of care and feeding, and doubly so when feeding is part of the data you’re trying to collect from them. Graduate student Katrina Nguyen learned this the hard way, but rather than let her life be controlled by a bunch of rodents, she hacked a solution that not only improved her life, but also improved her science. She kindly dropped by the Hackaday Superconference to tell us all about how she automated her research.

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Linux Fu: Controlling The Terminal

November 28, 2018 by Al Williams 17 Comments

A Linux terminal has a lot more features than the TeleType of yore. On a TeleType, text spews out and scrolls up and is gone forever. A real terminal can use escape characters to do navigate around and emulate most of what you like about GUIs. However, doing this at the lowest level is a chore and limits portability. Luckily, all the hard work has already been done.

First, there’s a large database of terminal capabilities available for you to use: terminfo. And in addition, there’s a high-level library called curses or ncurses that simplifies writing programs to control the terminal display. Digging deep into every nook and cranny of ncurses could take years. Instead, I’m going to talk about using a program that comes with ncurses to control the terminal, called tput. Using these two commands, you can figure out what kind of terminal you’re dealing with, and then manipulate it nearly to your heart’s content. Let’s get started!

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