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Hackaday Prize Entry: A Low Cost, Open Source MRI

This low cost magnetic resonance imager isn’t [Peter]’s first attempt at medical imaging, and it isn’t his first project for the Hackaday Prize, either. He’s already built a CT scanner using a barium check source and a CCD marketed as a high-energy particle detector. His Hackaday Prize entry last year, an Open Source Science Tricorder with enough sensors to make [Spock] jealous, ended up winning fourth place.

[Peter]’s MRI scanner addresses some of the shortcomings of his Open Source CT scanner. While the CT scanner worked, it was exceptionally slow, taking hours to image a bell pepper. This was mostly due to the sensitivity of his particle detector and how hot a check source he could obtain. Unlike highly radioactive elements, you can just make high strength magnetic fields, making this MRI scanner potentially much more useful than a CT scanner.

There are a few things that make a low-cost MRI machine possible, the first being a way to visualize magnetic fields. For this, [Peter] is using an array of Honeywell HMC5883L 3-axis magnetometers, the smallest sensors he could find with the largest range. These magnetometers are I2C devices, so with a few multiplexers it’s actually a relatively simple build.

Imaging with these magnetometers is not simple, and it’s going to take a lot of work to make a signal from all the noise this magnetic camera will see. The technique [Peter] will use isn’t that much different from another 2014 Hackaday Prize entry, A Proton Precession Magnetometer. When a proton in your body is exposed to a high strength magnetic field, it will orient towards the high strength field. When the large field is turned off, the proton will orient itself towards the next strongest magnetic field, in this case, the Earth. As a proton orients itself to the Earth’s magnetic field, it oscillates very slightly, and this decaying oscillation is what the magnetic camera actually detects.

With some techniques from one of [Peter]’s publication, these oscillations can be turned into images. It won’t have the same resolution as an MRI machine that fills an entire room, but it will work. Imagine, an MRI device that will sit on a desktop, made out of laser-cut plywood. You can’t have a cooler project than that.

The 2015 Hackaday Prize is sponsored by:

Filed under: The Hackaday Prize


Improving Active Loads

[Texane]’s job requires testing a few boards under a set of loads, and although the lab at work has some professional tools for this it seemed like a great opportunity to try out the Re:load 2. It’s a nifty little active load that’s available can of course be improved with an injection of solder and silicon.

While the Re:load 2 is a nice, simple device that can turn up to 12 Watts directly into heat, it’s not programmable. The ability to create and save load profiles would be a handy feature to have, so [Texane] took a Teensy 3.1 microcontroller and installed a resistor divider in front of the Re:load’s amplifier. A simple script running on a computer allows [Texane] to set the amount of current dumped and automate ramps and timers.

There is a more fundamental problem with the Re:load; the lowest possible current that can be dumped into a heat sink is 90mA. [Texane] replace the amplifier with a zero-drift amp that brought that 90mA figure down to 7mA.

Of course the Re:load and Teensy 3.1 are sold in the Hackaday store, but if you’re looking for a ready-built solution for a computer-controlled active load you can always check out the Re:load Pro, a fancy-smanchy model that has an LCD. The Pro costs more, and [Texane] just told you how to get the same features with the less expensive model we’re selling, though…

Filed under: tool hacks


Vintage Computer Festival Europa 16.0: The Hackaday Report

The 16th annual Vintage Computer Festival Europa (VCFe) is still ongoing this weekend in Munich, and of course Hackaday had to swing by. If you’re anywhere in Germany, you’ve still got until Sunday at 16:30 to check it out.

DSCF7896The theme for this year’s festival is “The East is Red Colorful” and that means vintage computers from the other side of the Iron Curtain. Here in (West) Germany, that naturally means a good representation of computers from the former Democratic Republic of Germany (DDR), but Czechoslovakia, Yugoslavia, and of course Russia were also in the house. There was far too much going on to cover it all, but here’s a few of the projects and computers that caught our eye.


DSCF7900_2This little blue beauty is testament to necessity being the mother of invention. In the mid-80s in Yugoslavia, it was illegal to import computers. You could try your luck getting through customs, and some did, but with microcomputer prices hovering around a month’s salary it wasn’t a good bet. Nevertheless, a few Z80s and Commodore 64s had gotten through customs, and there was a tiny microcomputer scene in the country. This all changed in December 1983 with the publication of the schematics for the Galaksija (Galaxy) computer in the science magazine of the same name.

The Galaksija plans consisted of one single-sided PCB that included everything: processor, keyboard, and memory. It had to be manufacturable at home, cheap, and yet functional. Basically everything about the design is a response to these three constraints. There’s no video chip, for instance. PAL TV output was bit-banged by the Z80 CPU, taking 80-90% of CPU cycles just to draw the screen. Cleverly, the video output could be turned off in code when the programmer needed the chip for number crunching, so this wasn’t quite as bad as it sounds.

The OS, BASIC language, and everything else was crammed into a 4KB of EEPROM, and it was a tight fit. To make it work, the Galaksija uses its own version of BASIC. They saved on memory by storing only the first letter of each command in the BASIC interpreter, but this means that some conflicts had to be worked around. For instance, instead of “LOAD” the Galaksija used the command “OLD” to load an existing program from cassette storage to avoid a collision with “LOOP”. (Note the CD player with a recording of old cassette data on the left.)

Despite being a serious hack, it was a runaway success. The designers of the computer also sold a kit through the magazine, and estimated that around 100 or so people would build their design. More than 8,000 kits are known to have been sold, and nobody has any idea how many more readers went the full-DIY route. For individuals who wanted to get into home computing, it was the only game in town.

Returning to the box in question, one aspect we love DIY work is the way that the builder’s spirit can shine through. Unlike most Galaksija computers which lie flat on their single PCB, this PCB was cut in half at the keyboard and re-attached at a more ergonomic angle. The all-metal case is completely custom, and quite a nice piece of work. (Most Galaksija never even had a case built for them, but sat naked on the PCB.) And you can even see the owner’s ghost in the R key, displaying a phenomenon more familiar to us with W, A, S, or D. R was the fire button in his favorite video game. (The current R key is actually a shift key re-painted. The shift key is taken from a later PC, covered over with nail polish, and simply soldered in place.) That corporate Dell just doesn’t tell stories like this.

The Ascota 170


For a while in the late 1950’s the Ascota 170 was one of the most powerful electro-mechanical computers on the market. Manufactured by the VEB Bookkeeping Machines Factory in Karl-Marx City, it was essentially a computer that would do everything an accounting secretary for a large company would need. It typed automatically, calculated, and stored values in its 15 (mechanical) registers. One machine could do four (!) calculations in parallel.


The two examples on display were trucked up from around Trento, Italy just for the festival. The owners didn’t know how much they weighed, but described them as “heavy”. If you’ve played around with mechanical typewriters, you’d recognize the smell of typewriter oil that filled the air around the two desk-mounted units and even spilled out onto the cardboard that the owners had thoughtfully covered the floor with under the unit on the left. They clicked, whirred, and were in continual motion — for some reason the typewriter ribbons continually spun in some kind of ancient wear-levelling scheme. In short, they were awesome.

DSCF7885_2One machine had add, subtract, and subtotal. The other, later, model had the optional multiplication co-processor shown here. Much bigger than a breadbox and driven by its own separate motor, the co-processor was connected by this cable as thick as your fist. Think about how this works for a second: you have an all-mechanical adding machine that you want to add an all-mechanical multiplication machine onto. You certainly don’t want to tie them together with a spider’s web of strings and pulleys. Instead, a bunch of electro-mechanical relays turn the mechanical closing of contacts into electrical signals that then pass through the cable to be converted back into physical movement on the other side.

The owners are still trying to figure out the programming language for the beasts. Here’s a photo of one of the programs that they do have on hand. The metal card, around a yard wide, is placed in the typewriter part of the machine, just behind the paper roll, and is read side-to-side by a bunch of levers with rollers on them. Here’s a video of a different Ascota running a program.DSCF7888

While we were talking about the machine, a visitor came by and joked that they should unplug the devices at night because Germany’s trying to lower its power consumption to be able to turn off the nuclear power plants. The owner laughed politely, but then pointed out that the beasts actually run on a single AC electrical motor and draw between 80W at idle and under 200W at full tilt. We joked that if they oiled it up a little more maybe they could get them under 50W — after all, when it’s not actually throwing its levers around the main power loss is to friction.


Prepare to die! The Nemesis crew have restored a multi-user dungeon (MUD) of the early 1990’s and was serving it up on a period DECstation 5000 for the festival.

DSCF7891_2And speaking of old iron, the coolest display in the whole festival was this prototype high-resolution graphic terminal developed in the mid-80s at the Technical University of Munich (TUM). The white on this screen doesn’t glow like a monitor, but rather reads like a piece of paper. You’d be excused for thinking it was e-ink, but larger than a full sheet of paper and instantly updating.

But back to the game. Nemesis itself is written in LPC, an object-oriented C-like language written for MUDs. That’s not just of interest to computer scientists — when a player gets to a certain level in the MUD, they can edit the code themselves, adding on to the world and even editing the players themselves. “Wizards” aren’t just players of the game, but also creators within it. While most any MUD can claim to be the text-only precursor to today’s massively-multiplayer online games, Nemesis is additionally something like the programmer’s precursor to Minecraft. Plus ça change!

DSCF7902Naturally it’s romantic to play the game in green-on-black phosphor screen, but you don’t have to be a retro aficionado to get in on the action. Outside of the festival, [Snake] runs the server on a modern virtual machine. Just telnet to at port 2000 and you’re in. Get lamp.

Everything else

DSCF7868A lot of space was dedicated to the Robotron KC85 / KC87 family (“klein-computer”, literally small computer) and other similar devices based on the East German ripoff of the Z80 processor, the U880. Unfortunately, we didn’t get a chance talk to folks about them.


We forgot how marvelous the noise that’s made when you shoot an asteroid in Asteroids is when it comes out of a large speaker inside a wooden case. Even more surprising was how well Crystal Castles holds up after all these years when played with real trackballs. And in keeping with the East vs West theme of this year’s festival, we had to play a little Tetris.

DSCF7870Apple fanboys wouldn’t be disappointed either. No watches to be seen, but Apples ranging from the Apple I, through a number of Apple IIs, to an Apple LC pizza box were all represented. We shed a brief tear for our long-forgotten SE/30.

Rounding out the event, there were talks galore and a swap meet. In short, everything the vintage computer aficionado could desire. If you missed this one, there are a number of similar festivals going on in Europe and the US. Check out the US mother site or its German daughter for details.

And for the Czech side of things, don’t forget our own Martin Malý’s twin-post series on
Home Computers Behind The Iron Curtain and
Peripherals Behind The Iron Curtain.

Filed under: news, Uncategorized


Hackaday Prize Entry: BS Free USB

Take a look at some old electronics magazines, or even a few blog posts from 10 years ago, and you’ll notice something strange: parallel ports. Those big ‘ol DB25 were the way to get bits out of a computer and into a microcontroller. There was a reason for this: it was exceptionally easy to do.

Now, we have USB to deal with, and that means VIDs and PIDs, drivers, enumeration, and a whole bunch of cruft that makes blinking an LED a surprisingly complicated process. [Colin O’Flynn]’s project for the 2015 Hackaday Prize aims to fix that with BSU – BS Free USB.

Instead of USB to serial chips attached to another microcontroller, [Colin] is using a few microcontrollers with a built-in USB interfaces. These chips are loaded up with firmware and controlled with a simple API on the computer side. If you want to blink a pin, just add a library to your project and set the pin high. Want some SPI on your computer? That’s just setting a few pins as MOSI, MISO, and SCK and typing in a few bytes. It’s basically a Bus Pirate that you can stick into any project.

If [Colin]’s name sounds familiar in the context of The Hackaday Prize, it’s because he won second place with the ChipWhisperer last year. While a tiny USB thing isn’t quite as cool as a tool to break embedded encryption, the BSU certainly seems more useful to millions of hardware tinkerers around the world.

The 2015 Hackaday Prize is sponsored by:

Filed under: Microcontrollers, The Hackaday Prize


Aspectus adds a beautiful music widget to Reachability

There are a bunch of tweaks on Cydia which provide a collection of widgets to be added to Reachability. One such tweak is Aspectus which has been released recently by iOS developers S1ris and JoeyJreij.
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3D Printing an Arcade Controller

A keyboard and mouse simply can’t stand in for games originally meant to be played with a joystick and buttons. We are of course thinking of coin-op here and building your own set of arcade controls is a great project to give back some of the thrill of those classics. But these are not trivial builds and may push your comfort zone when it comes to fabrication. Here’s one alternative to consider: 3D printing an arcade controller housing.

3d-printed-arcade-controller-thumb[Florian] already had experience building these using laser cut acrylic and MDF. This is his first foray into a 3D printing build method for the controller body. The top is too large to easily produce as a single piece on inexpensive printers. He broke it up into sections; eleven in total. When the printing is complete he chemically welds them together using a slurry of acetone and leftover ABS.

We think one possible extension of this technique would be to build a mounting system that would allow you to swap out segments (instead of welding them all) while you dial in the exact placement that you want for each component. You know, like when you decide that rectangular button pattern doesn’t fit your hand. That said, this looks like a beautiful and functional build. At the least it’s a great way to practice your 3D printing skills and you end up with a wicked controller at the end of it.

Filed under: 3d Printer hacks


$50k In Play: Giving Away 50 LightBlue Bean This Week

This week we’re awarding a LightBlue Bean board to 50 projects entered in The Hackaday Prize.

We love this little board so much we put it in our store. It brings a microcontroller that has plenty of room and peripherals (and is quite well-known… the ATmega328) with the connectivity of Bluetooth Low Energy. If you’re planning on building something that needs processing power and connectivity with smartphones this is a good place to start. And this week you might just score one as part of the 2015 Hackaday Prize.

We’ll be looking for entries that are getting ready for the physical build and need connectivity. The best way to let us know your project should be one of the fifty winners is to post a new project log with your construction plans and how the Bean (or BTLE) would fit into that plan. Submit your build by next Wednesday and you’re in the running!

We’re giving away ,000 in prizes, 1/10 of the total Hackaday Prize pool during the build phase going on right now.

Last Week’s 30 Winners


Last week we were looking for great entries in need of circuit boards and boy, did we find a lot of them. Judging is super hard. We looked at all the entries and ended up with these 30 winners. Each will receive to use for custom PCB manufacturing from OSH Park. We expect to see a lot more purple boards popping up on entry pages in the coming weeks! Congratulations to all winners. Each project creator will find prize info as a message on

  • 0 CT Scanner
  • Algorithmic Composter
  • An IOT Device That Tells Dad the Stove is Off.
  • Arduino MPPT Solar charging
  • Binary Fuel Tank
  • Blockits
  • Chocometer
  • Dual channel battery charger
  • eink Pi display
  • eye drive wheelchair
  • Gas Sensor For Emgergcy Workers
  • Guerillamesh
  • Internet enabled smoke alarm
  • Medical Tricorder
  • Open Ground Penetrating Radar
  • Open Source Cell Phone
  • Pathfinder Haptic Navigation
  • Portable environmental monitor
  • satSEND
  • SentriFarm
  • Share the warmth
  • Smart Fridge
  • Smart Solar Lamp
  • Subpos
  • TactTiles
  • Terra Spider
  • The Vision Project
  • Wireless battery mouse

The 2015 Hackaday Prize is sponsored by:

Filed under: The Hackaday Prize


Teardown: An Electronic Master Lock

[rohare] has an interesting teardown for us over on the keypicking lock picking forums. It’s a Masterlock combination lock – specifically the Masterlock 1500eXD – and yes, it’s a completely electronic lock with buttons and LEDs. Think that’s the mark of a terrible lock? You might be surprised.

The first impressions of this lock were surprisingly positive. It was heavy, the shackle doesn’t move at all when you pull on it. Even the buttons and LEDs made sense. Once the back of the lock was drilled open, things got even more impressive. This lock might actually be well-built, with a ‘butterfly’ mechanism resembling a legendary padlock, actuated by a small but sufficient motor. Even the electronics are well-designed, with the programming port blocked by the shackle when it’s closed. [rohare] suspects the electronics aren’t made by Masterlock, but they are installed in a very secure enclosure.

The teardown concludes with a fair assessment that could also be interpreted as a challenge: [rohare] couldn’t find any obvious flaws to be exploited, or a simple way to break the lock. He concludes the most probable way of breaking this lock would be, “knowing some trick of logic that bypasses the codes on the electronics”. That sounds like a good enough challenge for us, and we’re eagerly awaiting the first person to digitally unlock this physical lock.

Filed under: lockpicking hacks, teardown


Hackaday Retro Edition: TRS Wiki

1977 was a special year for computing history; this year saw the release of the 8085 following the release of the Z80 a year before. Three companies would launch their first true production computers in 1977: Apple released the Apple II, Commodore the PET 2001, and Tandy / Radio Shack the TRS-80 Model I. These were all incredibly limited machines, but at least one of them can still be used to browse Wikipedia.

[Pete]’s TRSWiki is a Wikipedia client for the TRS-80 Model I that is able to look up millions of articles in only uppercase characters, and low resolution (128×48) graphics. It’s doing this over Ethernet with a very cool Model I System Expander (MISE) that brings the lowly Trash-80 into the modern era.

The MISE is capable of booting from CF cards, driving an SVGA display and connecting to 10/100 Ethernet. Connecting to the Internet over Ethernet is one thing, but requesting and loading a web page is another thing entirely. There’s not much chance of large images or gigantic walls of text fitting in the TRS-80’s RAM, so [Pete] is using a proxy server on an Amazon Web Services box. This proxy is written in Java, but the code running on the TRS-80 is written entirely in Z80 assembly; not bad for [Pete]’s first project in Z80 assembly.

vt100normal The Hackaday Retro Edition is our celebration of old computers doing something modern, in most cases loading the old, no CSS or Javascript version of our site.

If you have an old computer you’d like featured, just load up the retro site, snap some pictures, have them developed, and send them in.

Filed under: classic hacks, Hackaday Columns


The Infinite Bar(T)

Combining an Android app with some fluid pumps, an infinity mirror, and a whole lot of booze — let us introduce BarT — the Automated Bartender.

It’s the work of [dosko27] for his senior design project in Electrical Engineering. It’s an automated and wireless drink mixology system. Since it’s for school, the demonstration video doesn’t have any “hard drinks” but the ingredients (up to sixteen) are completely up to you.

He started off with the case. It’s your standard infinity mirror build, a mirror, a 1-way mirror, and some programmable RGB LEDs. We covered a great build tutorial on how to make your own a few years ago. Unlike most automated bar units, [dosko27] opted for a simple, yet elegant design hiding all the electronics. One small LCD to name your drink, and one small spot to stick your cup.

He designed a custom PCB bank of solenoid drivers to control the valves on each ingredient. The trickiest (and most expensive) part with most of these builds is a pump for every ingredient — so instead, he’s using a CO2 supply to pressurize the bottles. This cuts the cost of the build, although you will have to supply CO2 now.

For more great barbot builds, check out the Roboxotica festival in Vienna for some inspiration for your next robotic bartender build!

Filed under: Arduino Hacks, cooking hacks