A Simple And Educational Brushless Motor

April 23, 2016 by Jenny List 36 Comments

Sometimes there is no substitute for a real working model to tinker with when it comes to understanding how something works. Take a brushless motor for example. You may know how they work in principle, but what factors affect their operation and how do those factors interact? Inspired by some recent Hackaday posts on brushless motors, [Matt Venn] has built a simple breadboard motor designed for the curious to investigate these devices.

The rotor and motor bodies are laser-cut ply, and the rotor is designed to support multiple magnet configurations. There is only one solenoid, the position of which relative to the magnets on the rotor can be adjusted. The whole assembly is mounted on the edge of a breadboard, and can be rotated relative to the breadboard to vary the phase angle at which the drive circuit’s Hall-effect sensor is activated by the magnet. The drive circuit in turn can have its gain and time constants adjusted to study their effects on the motor’s running.

[Matt] has made all the design files available in his GitHub repository, and has recorded a comprehensive description of the motor’s operation in the YouTube video below the break. Continue reading “A Simple And Educational Brushless Motor” →

This Teddy Bear Steals Your Ubuntu Secrets

April 22, 2016 by Elliot Williams 20 Comments

Ubuntu just came out with the new long-term support version of their desktop Linux operating system. It’s got a few newish features, including incorporating the “snap” package management format. One of the claims about “snaps” is that they’re more secure — being installed read-only and essentially self-contained makes them harder to hack across applications. In principle.

[mjg59] took issue with their claims of increased cross-application security. And rather than just moan, he patched together an exploit that’s disguised as a lovable teddy bear. The central flaw is something like twenty years old now; X11 has no sense of permissions and any X11 application can listen in on the keyboard and mouse at any time, regardless of which application the user thinks they’re providing input to. This makes writing keylogging and command-insertion trojans effortless, which is just what [mjg59] did. You can download a harmless version of the demo at [mjg59]’s GitHub.

This flaw in X11 is well-known. In some sense, there’s nothing new here. It’s only in light of Ubuntu’s claim of cross-application security that it’s interesting to bring this up again.

And the teddy bear in question? Xteddy dates back from when it was cool to display a static image in a window on a workstation computer. It’s like a warmer, cuddlier version of Xeyes. Except it just sits there. Or, in [mjg59]’s version, it records your keystrokes and uploads your passwords to shady underground characters or TLAs.

We discussed Snappy Core for IoT devices previously, and we think it’s a step in the right direction towards building a system where all the moving parts are only loosely connected to each other, which makes upgrading part of your system possible without upgrading (or downgrading) the whole thing. It probably does enhance security when coupled with a newer display manager like Mir or Wayland. But as [mjg59] pointed out, “snaps” alone don’t patch up X11’s security holes.

Hackaday Dictionary: USB Type C

April 22, 2016 by Richard Baguley 75 Comments

USB cables? What a pain. You can never find the right type of connector when you need one, or you can’t figure out which way is up when you plug the cable in. These problems could be a thing of the past, though, with the latest version of the venerable USB connection: USB Type C. This new standard uses a single style of plug for both ends, so you can use cables either way around. The plugs also work both ways up, so you can plug it in with your eyes closed. Let’s take a look at what the USB type C connector means.

Continue reading “Hackaday Dictionary: USB Type C” →

Pine64: The Un-Review

April 21, 2016 by Brian Benchoff 160 Comments

Even before the announcement and introduction of the Raspberry Pi 3, word of a few very powerful single board ARM Linux computers was flowing out of China. The hardware was there – powerful 64-bit ARM chips were available, all that was needed was a few engineers to put these chips on a board, a few marketing people, and a contract manufacturer.

One of the first of these 64-bit boards is the Pine64. Introduced to the world through a Kickstarter that netted $1.7 Million USD from 36,000 backers, the Pine64 is already extremely popular. The boards are beginning to land on the doorsteps and mailboxes of backers, and the initial impressions are showing up in the official forums and Kickstarter campaign comments.

I pledged $15 USD to the Pine64 Kickstarter, and received a board with 512MB of RAM, 4K HDMI, 10/100 Ethernet and a 1.2 GHz ARM Cortex A53 CPU in return. This post is not a review, as I can’t fully document the Pine64 experience. My initial impression? This is bad. This is pretty bad.

Continue reading “Pine64: The Un-Review” →

Hacking When It Counts: POW Canteen Radios

April 21, 2016 by Dan Maloney 55 Comments

Of all the horrors visited upon a warrior, being captured by the enemy might count as the worst. With death in combat, the suffering is over, but with internment in a POW camp, untold agonies may await. Tales of torture, starvation, enslavement and indoctrination attend the history of every nation’s prison camps to some degree, even in the recent past with the supposedly civilizing influence of the Hague and Geneva Conventions.

But even the most humanely treated POWs universally suffer from one thing: lack of information. To not know how the war is progressing in your absence is a form of torture in itself, and POWs do whatever they can to get information. Starting in World War II, imprisoned soldiers and sailors familiar with the new field of electronics began using whatever materials they could scrounge and the abundance of time available to them to hack together solutions to the fundamental question, “How goes the war?” This is the story of the life-saving radios some POWs managed to hack together under seemingly impossible conditions.

Continue reading “Hacking When It Counts: POW Canteen Radios” →

Liberté, Égalité, Fraternité, AZERTY

April 20, 2016 by Brian Benchoff 30 Comments

In the US, we don’t hear much about computing from beyond the Anglosphere. We’ve seen some home computer clones from behind the iron curtain, but getting any information about them is hard. If you find an old keyboard with a QWERTZ layout, or even a few Cyrillic characters, in the States, it’s a rarity. To date, the only French computer on Hackaday is an old Minitel dumb terminal. To help rectify this, [Jeremie Marsin], [Thierry Mazzoleni], and [Jean Paul Mari] from Quebec brought the best of the French computing revolution of the 1980s along to this year’s Vintage Computer Festival East

The evolution of the reigning champion of this exhibit begins with the Micronique Victor Lambda, a licensed copy of a purely American computer, the Interact Home Computer System. This computer featured a 2 MHz 8080A, 8 or 16 kB of RAM, and was quickly discontinued. The French company Micronique quickly bought the original designs and remarketed the computer in France.

In a few short years, Micronique took this design and turned it into the Hector. This machine featured a 5 MHz Z80, 48 kB of RAM, high resolution graphics (243×231 at four colors) and included BASIC and Forth interpreters.

The Victor and Hector were the best home computers at the time, but for every Commodore or Apple, you need a ZX Spectrum. France’s version of this tiny computer with a terrible keyboard was the Matra Alice 32, a computer with a 1 MHz 6803, 16kB of Ram, and a real 80×25 text mode. The Alice is heavily based on the American TRS-80 MC-10, with a SCART connector and an AZERTY keyboard.

The weirdest computer [Jeremie], [Thierry], and [Jean Paul] brought out? That would be the Excelvision EXL100. The 1980s, for better or worse, were the times of the Z80 and 6502. The EXL100 was running something completely different. This home computer used a TMS7020 CPU from Texas Instruments, a speech synthesizer, and a wireless keyboard. Very strange for the time and relatively inexpensive; in 1984 this computer cost only ₣3190, or about $550 USD.

[Jeremie], [Thierry], and [Jean Paul] had an exhibit that presented the best the Francosphere had to offer to the computing world in the 80s and 90s. We haven’t seen enough early computers from outside the US, so we’re happy to have met these guys at the 11th annual Vintage Computer Festival East.

[Sprite_tm] Gives Near Death VFD A Better Second Life

April 20, 2016 by Elliot Williams 16 Comments

[Sprite_tm] picked up some used VFD displays for cheap, and wanted to make his own custom temperature and air-quality display. He did that, of course, but turned it into a colossal experiment in re-design to boot. What started out as a $6 used VFD becomes priceless with the addition of hours of high-powered hacking mojo.

You see, the phosphor screen had burnt-in spots where the old display was left static for too long. A normal person would either live with it or buy new displays. [Sprite_tm] ripped off the old display driver and drives the row and column shift registers using the DMA module on a Raspberry Pi2, coding up his own fast PWM/BCM hybrid scheme that can do greyscale.

He mapped out the individual pixels using a camera and post processing in The Gimp to establish the degradation of burnt-in pixels. He then re-wrote a previous custom driver project to compensate for the pixels’ inherent brightness in firmware. After all that work, he wrapped the whole thing up in a nice wooden frame.

There’s a lot to read, so just go hit up his website. High points include the shift-register-based driver transplant, the bit-angle modulation that was needed to get the necessary bit-depth for the grayscale, and the PHP script that does the photograph-based brightness correction.

Picking a favorite [Sprite_tm] hack is like picking a favorite ice-cream flavor: they’re all good. But his investigation into hard-drive controller chips still makes our head spin just a little bit. If you missed his talks about the Tamagotchi Singularity from the Hackaday SuperCon make sure you drop what you’re doing and watch it now.