Hackaday Columns

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This excellent content from the Hackaday writing crew highlights recurring topics and popular series like Linux-Fu, 3D-Printering, Hackaday Links, This Week in Security, Inputs of Interest, Profiles in Science, Retrotechtacular, Ask Hackaday, Teardowns, Reviews, and many more.

RC receiver to arduino converter for BB-8

Ask Hackaday: How Do You Convert Negative Voltages To Positive?

November 14, 2016 by 81 Comments

I have a good background working with high voltage, which for me means over 10,000 volts, but I have many gaps when it comes to the lower voltage realm in which RC control boards and H-bridges live. When working on my first real robot, a BB-8 droid, I stumbled when designing a board to convert varying polarities from an RC receiver board into positive voltages only for an Arduino.

Today’s question is, how do you convert a negative voltage into a positive one?

In the end I came up with something that works, but I’m sure there’s a more elegant solution, and perhaps an obvious one to those more skilled in this low voltage realm. What follows is my journey to come up with this board. What I have works, but it still nibbles at my brain and I’d love to see the Hackaday community’s skill and experience applied to this simple yet perplexing design challenge.

The Problem

RC toy truck and circuit with no common
RC toy truck and circuit with no common

I have an RC receiver that I’ve taken from a toy truck. When it was in the truck, it controlled two DC motors: one for driving backwards and forwards, and the other for steering left and right. That means the motors are told to rotate either clockwise or counterclockwise as needed. To make a DC motor rotate in one direction you connect the two wires one way, and to make it rotate in the other direction you reverse the two wires, or you reverse the polarity. None of the output wires are common inside the RC receiver, something I discovered the hard way as you’ll see below.

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Hackaday Links: November 13, 2016

November 13, 2016 by 16 Comments

The Travelling Hackerbox is going International. I wrote a post on this earlier in the week, and I’m still looking for recipients for the box that are not in the United States. The sign-up form is right here, [the sign up form is now closed] and so far we have good coverage in Canada, Australia, NZ, Northern Europe, and a few in Africa. If you ever want to be part of the Travelling Hackerbox, this is your chance. I’m going to close the sign-up sheet next week. Sign up now.

Like the idea of a travelling hackerbox, but are too impatient? Adafruit now has a box subscription service. Every quarter, an AdaBox will arrive on your doorstep packed to the gills with electronic goodies.

The very recently released NES Classic edition is the 2016 version of the C64 DTV — it’s a Linux system, not as elegant, and there’s little hacking potential. If you want to increase the amount of storage, desolder the Flash chip (part no. S34ML04G200TFI000), and replace it with a larger chip. The NES Classic edition isn’t the coolest retro system coming out — Genesis is back, baby. Brazil has had a love affair with the Genesis/Mega Drive because of their bizarre import restrictions. Now, the manufacturer of the Brazilian Sega clones is releasing a Linux-ified clone. Does anyone know how to export electronics from Brazil?

The CFP deadline for the SoCal Linux Expo is fast approaching. You have until the 15th to get your talks in for SCALE.

Let’s talk about dissolvable 3D printer support material. One of the first materials able to be printed and removed by dissolving in water was PVA. Makerbot sold it for use in their dual extruder machines. PVA does dissolve, but it degrades at higher temperatures and kills nozzles. HIPS can be dissolved with limonene, but it’s really only for use in conjunction with ABS. This week, E3D released their Scaffold support material. It’s a PVA/Polyvinyl alcohol filament — ‘the stuff gel caps are made out of’ was the line we got when E3D previewed Scaffold at MRRF last March. It’s a support material that’s water dissolvable, compatible with most filaments, and is able to produce some amazing prints. It’s available now, but it is a bit pricey at £45 for half a kilo. Brexit is a good thing if you’re paid in dollars.

If you’re into chiptunes, you’ve heard about Little Sound DJ. LSDJ is a cart/ROM capable of toggling all the registers on the Game Boy sound chip, sequencing bleeps and bloops, and generally being awesome. The recently released Nanoloop Mono is not Game Boy software. It’s a few op-amps and a PIC micro pasted on a board that turns the Game Boy into a synth. You get a significantly more 80s sound with the Nanoloop Mono over LSDJ, audio input, and a step sequencer.

Hackenings: KiCAD, Science, DevOps, And Cyber

November 12, 2016 by 4 Comments

This week in [Hackenings], we’ve got a full roster of interesting upcoming events scattered all over the world. Can’t afford airfare to India, but Dublin is in the next county over? We’ve got you covered.

KiCad in Bangalore

IKP EDEN, in Bangalore, is hosting an Introduction to KiCad workshop on Sunday, Nov 13 from 10:00-2:00 pm. If you’re just getting started with PCB layout, or just want a quickstart learning KiCad, Hackaday contributor [Anool Mahidharia] will be there to show you how! Sign up on the link above, and bring your laptop with KiCad already installed.

Science in Dublin

20151115_124704-e1476655395528_thumbnailTOG hackerspace in Dublin is putting on their fifth annual Science Hack Day, a 36-hour hardware and software hackathon on Nov 19 & 20th. Looking through their photos, past creations have included a laser mission-impossible crawl-through maze thing, some kind of freaky turtle, and many objects that move, make noise, or otherwise amuse.

“Each year we bring together, designers, coders, scientists, engineers and makers. Simply to make interesting things. Why? For adventure, for playfulness, for science!”

DevOppery (and Foppery) in Stuttgart

logo_webDo you have what it takes to meet the needs of DevOps, Agile, and Cyber in the Enterprise Environment? Interested in Disruptive Cloud Computing or Mobile First Growth Hacking? Can you rub two buzzwords together and come up with marketing gold? Then you might have a fun time at the shack hackerspace in Stuttgart on Nov. 19th, for the eloop 2016 conference (translated here).

A full day’s talks include topics such as “Enterprise Patterns”, “Good Enough”, and the “Cult of Done Manifesto” as it relates to computer security. “What’s discussed at eloop today moves the digital markets of tomorrow.” YOLO!

Vote for Swindon

If you’re a UK citizen, you can vote to get the Swindon Makerspace some community funding so that they can furnish a new space. Why not?

Game Retro

And if you’re in Huntsville, Alabama, or environs, don’t forget Makers Local 256’s Retro Gaming night tonight (Saturday, 12th).

Hackenings? Hackenings!

[Hackenings] is our weekly Saturday morning (US, Pacific Time) roundup of what’s going to be going on in the hackerspace world in the upcoming week. If you’d like us to cover your event, email us at tips@hackaday.com and put [Hackenings] in the subject so that we don’t miss it. Thanks!

Retrotechtacular: The Golden Book Of Chemistry Experiments

November 11, 2016 by 33 Comments

Back in “the old days” (that is, when I was a kid), kids led lives of danger and excitement. We rode bikes with no protective gear. We stayed out roaming the streets after dark without adult supervision. We had toy guns that looked like real ones. Dentists gave us mercury to play with. We also blew things up and did other dangerous science experiments.

If you want a taste of what that was like, you might enjoy The Golden Book of Chemistry Experiments. The book, first published in 1960, offers to show you how to set up a home laboratory and provides 200 experiments. The colorfully illustrated book shows you how to do some basic lab work as well as offering some science history and terminology.

Want to make oxygen? There’s several methods on page 27. Page 28 covers making hydrogen. To test the hydrogen for purity, the suggest you collect a test tube full, invert it, and stick a match up to the tube. If the hydrogen is pure it will burn with a pop noise. If air is mixed it, it will explode. Yeah, that sound safe to us.

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Creating A PCB In Everything: Protel Autotrax

November 10, 2016 by 37 Comments

Protel Autotrax is a PCB design tool first released for DOS in the mid-80s. Consider this a look at the history of PCB design software. I’m not recommending anyone actually use Protel Autotrax —  better tools with better support exist. But it’s important to know where we came from to understand the EDA tools available now. I’m rolling up my sleeves (about 30 years worth of rolling) and building our standardized test PCB with the tool. Beyond this, I suggest viewing EEVblog #747, where [Dave] digs into one of his old project, Borland Pascal, and Protel Autotrax.

This is the continuation of a series of articles demonstrating how to Create A PCB In Everything. In this series, we take a standard reference circuit and PCB layout — a simple ATtiny85 board — and build it with different PCB design tools. We’ve already covered Eagle in this series. We learned Fritzing is a joke for PCB design, although it is quite good for making breadboard graphics of circuits. Each of these tutorials serves as a very quick introduction to a specific PCB design tool. Overall, this series provides for a comparison between different PCB design tools. Let’s dig into Protel Autotrax.

A short history of Protel, Altium, and Autotrax

The company we know as Altium today was, for the first fifteen years of its existence, known as Protel. Back in the day, PCB design on a computer required a dedicated workstation, a lot of hardware, light pens, and everything was extraordinarily expensive. Protel was a reaction to this and the first product, Autotrax, was a DOS-based program that brought PCB design to the PC. A freeware version of Autotrax is still available on the Altium website and can be run from inside a DOS virtual machine or DOSBox.

Interestingly, Protel Autotrax is not the only PCB design software named Autotrax. A company called DEX 2020 has also has a PCB design software called AutoTRAX. This is weird, confusing, and I can’t figure out how this doesn’t violate a trademark. If anyone has any insight to what the Protel / Altium legal department was doing a few decades ago, your wisdom is welcome in the comments.

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Visual Guide To The Best Hacker T-Shirts

November 9, 2016 by 16 Comments

Head out in the normal “civilian” world and look at the shirts around you. I don’t want to be too nasty about about it, but let’s face facts — the T-shirts you see will be boring and uninventive. Now compare that to your favorite hacker cons. We wear our shirts like they’re oil paintings.

Going into the weekend of SuperCon I had no intention of writing this post. But then I saw a really awesome shirt and already had the camera in my hands so I asked if I could snap a picture. A bit later that day it happened again. Then I don’t know what came over me. Here are my favorites, but I’ve curated an epic number of great garments for your viewing pleasure after the break.

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My Life In The Connector Zoo

November 9, 2016 by 45 Comments

“The great thing about standards is that there are so many to choose from.” Truer words were never spoken, and this goes double for the hobbyist world of hardware hacking. It seems that every module, every company, and every individual hacker has a favorite way of putting the same pins in a row.

We have an entire drawer full of adapters that just go from one pinout to another, or one programmer to many different target boards. We’ll be the first to admit that it’s often our own darn fault — we decided to swap the reset and ground lines because it was convenient for one design, and now we have two adapters. But imagine a world where there was only a handful of distinct pinouts — that drawer would be only half full and many projects would simply snap together. “You may say I’m a dreamer…”

This article is about connectors and standards. We’ll try not to whine and complain, although we will editorialize. We’re going to work through some of the design tradeoffs and requirements, and maybe you’ll even find that there’s already a standard pinout that’s “close enough” for your next project. And if you’ve got a frequently used pinout or use case that we’ve missed, we encourage you to share the connector pinouts in the comments, along with its pros and cons. Let’s see if we can’t make sense of this mess.

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