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Ask Hackaday: A Robot’s Black Market Shopping Spree

จันทร์, 01/05/2015 - 04:01

It was bad when kids first started running up cell phone bills with excessive text messaging. Now we’re living in an age where our robots can go off and binge shop on the Silk Road with our hard earned bitcoins. What’s this world coming to? (_sarcasm;)

For their project ‘Random Darknet Shopper’, Swiss artists [Carmen Weisskopf] and [Domagoj Smoljo] developed a computer program that was given 100 dollars in bitcoins and grated permission to lurk on the dark inter-ether and make purchases at its own digression. Once a week, the AI would carrying out a transaction and have the spoils sent back home to its parents in Switzerland. As the random items trickled in, they were photographed and put on display as part of their exhibition, ‘The Darknet. From Memes to Onionland’ at Kunst Halle St. Gallen. The trove of random purchases they received aren’t all illegal, but they will all most definitely get you thinking… which is the point of course. They include everything from a benign Lord of the Rings audio book collection to a knock-off Hungarian passport, as well as the things you’d expect from the black market, like baggies of ecstasy and a stolen Visa credit card. The project is meant to question current sanctions on trade and investigate the world’s reaction to those limitations. In spite of dabbling in a world of questionable ethics and hazy legitimacy, the artists note that of all the purchases made, not a single one of them turned out to be a scam.

Though [Weisskopf] and [Smoljo] aren’t worried about being persecuted for illegal activity, as Swiss law protects their right to freely express ideas publicly through art, the implications behind their exhibition did raise some questions along those lines. If your robot goes out and buys a bounty of crack on its own accord and then gives it to its owner, who is liable for having purchased the crack?

If a collection of code (we’ll loosely use the term AI here) is autonomous, acting independent of its creator’s control, should the creator still be held accountable for their creation’s intent? If the answer is ‘no’ and the AI is responsible for the repercussions, then we’re entering a time when its necessary to address AI as separate liable entities. However, if you can blame something on an AI, this suggests that it in some way has rights…

Before I get ahead of myself though, this whole notion circulates around the idea of intent. Can we assign an artificial form of life with the capacity to have intent?


Filed under: Ask Hackaday, Hackaday Columns, internet hacks

Arduino vs. Phidgets – Dev Time Trials

จันทร์, 01/05/2015 - 01:00

Is developing on an Arduino too slow? Are Phidgets too expensive? When might you use one or the other? Hackaday regular [Ken] breaks down what he learned from three experimental time trials.

The main development differences between Arduino and Phidgets are a mix of flavor preferences and some hard facts. The Arduino is open source, Phidgets are proprietary. Arduino requires a mix of hard- and software where Phidgets only needs (and only allows) a connection to a full computer but enables high level languages – it is expected to get the job done sooner and easier. And finally, Arduinos are cheap, Phidgets are 3-5x the cost.

The three time trials were common tasks: 1. Blink an LED. 2. Use a pot to turn a servo. 3. Build a pedometer. For [Ken], the Phidgets won in each of the three experiments, but not significantly: 37%, 45%, and 25% respectively. The difference is only minutes. Even considering time value, for most hackers it is not worth the cost.

In context, the advantages of a mildly more rapid development on the simplest projects are wasted away by needing to rebuild a permanent solution. Chained to a PC, Phidgets are only useful for temporary or fixed projects. For many of our readers that puts them dead in the water. Arduinos may technically be dev kits but are cheap enough to be disposed of in the project as the permanent solution – probably the norm for most of us.

[Ken] points out that for the software crowd that abhor electronics, Phidgets plays to their preferences. Phidgets clips together their pricey peripherals and the rest is all done in code using familiar modern languages and libraries. We wonder just how large this group could still be; Phidgets might have been an interesting kit years ago when the gulf between disciplines was broader but the trend these days is towards everyone knowing a little about everything. Hackaday readers probably represent that trend more than most, but let us know if that seems off.

[Ken]’s article has much more and much better detailed explanations of the experiments and the tradeoffs between the platforms.

If you enjoy watching parallel engineering, see the time-lapse video below for a split screen of the time trials.


Filed under: reviews, Software Development

Upgrading DJI Flight Controllers

อาทิตย์, 01/04/2015 - 22:00

DJI, the company that gave us the far too popular Phantom line of quadcopters, doesn’t just make the most popular line of FPV quads. Their top of the line flight controller, The Naza V2, is very good, able to connect to flight planning software that will set waypoints, talk to peripherals over a CAN bus, and has improved flight algorithms. On the other hand, their ‘reduced price’ model, the Naza Light, can’t connect to these nifty CAN bus peripherals and has a bit of a problem with drifting the quad from one side or another.

The Naza V2 sells for around $300, and the Naza Light sells for about $170, both with a GPS module. The hardware inside the V2 and Light is exactly the same. We all know how this is going to go down, right?

[udnham] over on the RC Groups forum figured out a way to load the more capable Naza V2 firmware on the Naza Light, giving the cheaper flight controller features that were, until now, only found in the more expensive V2 hardware. The upgrades include better algorithms for GPS position and altitude hold, the ability to connect to DJI peripherals including the Bluetooth module, the iOSD, and camera gimbals, Octocopter support, the DJI datalink modem, and a bunch of other features.

Even though DJI is using the same hardware in the $170 Naza Light and the $300 Naza V2, upgrading the firmware requires an Internet connection to the DJI servers. [udnham] wrote a utility that modifies the /etc/hosts file on your computer, runs a service, and allows you to upgrade your firmware on the Naza Light. It’s basically a $130 firmware upgrade for a DJI flight controller that’s a single download away.

[udnham] set up a site where you can download the firmware flashing tool with a few videos showing the upgrade process and the improvement over the stock firmware. You can check those out below.


Filed under: drone hacks, slider

800 x 600 VGA With the STM32F4

อาทิตย์, 01/04/2015 - 19:00

Generating VGA is a perennial favorite on the Hackaday tips line, and it’s not hard to see why. Low-res video games, of course, but sending all those pixels out to a screen is actually a pretty challenging feat of coding. The best most project have attained is the original VGA standard, 640×480. Now that we have fast ARMs sitting around, we can bump that up to 800×600, like [Karl] did with an STM32F4 Discovery board.

The problem with generating VGA on a microcontroller is the pixel frequency – the speed at which pixels are shoved out of the microcontroller and onto the screen. For an 800×600 display, that’s 36 MHz; faster than what the 8-bit micros can do, but a piece of cake for the STM32F4 [Karl] is using.

[Karl] started his build by looking at the VGA project Artekit put together. It too uses an STM32, but a 36-pin F103 part. Still, it was fast enough to generate a line-doubled 800×600 display. [Karl] took this code and ported it over to the F4 part on the Discovery board that has enough space for a full 800×600 frame buffer.

With all that RAM on board the F4 part, [Karl] was able to expand the frame buffer and create a relatively high-resolution display with DMA and about a dozen lines of code. It looks great, and now we just need a proper application for high-resolution VGA displays. Retrocomputing? A high-resolution terminal emulator? Who knows, but it’s a great use for the STM32.

If circles and some text aren’t your thing, Artekit also has Space Invaders running on the 36-pin STM32.


Filed under: Microcontrollers

Sound Reactive Drums of Trailing Light

อาทิตย์, 01/04/2015 - 16:00

If you’re going to be the drummer in a band for a Back to the Future themed New Years Eve party, you really need to add something to your gig that captures that kitschy futuristic ambiance as seen by the 80s. Rainbow LEDs will do the trick.

For his drum set’s reactive trailing light display, [Alec Smecher] was inspired by a similar project he’d seen in the past where Neopixels were added to a regular drum kit and activated with several individual microphones. Since the microphones ultimately heard all of the thundering noise from every drum and cymbal at once, there was a lot of bleed over in the response of the LEDs. To remedy this, [Alec] used piezo pickups which listen to discrete surface vibrations rather than sound in order to clean up the effect produced by the lights. Each of the five LED strips lining the stands of his cymbal and inside of his drums were programmed to react with a burst of light equal in brightness to the intensity of the vibration sensed by the piezo.

To insure everything kept together amidst all the constant motion and shaking during performance, [Alec] soldered his connections directly onto his Trinket’s pins as well as the fragile pickup of the piezo. The pickup of the sensors were taped directly against the skin of his drums and along the inside of each cymbal to maximize responsiveness. After ringing in the new year appropriately as the ‘band from the future’, [Alec] reports that his colorful addition worked fantastic the whole night.

Those interested in building their own can find a nice schematic on [Alec’s] blog as well as the code he used on github. Difficulty level taken into account, this is a great first project for a musician who has yet to dabble in electronics… and seeing that it’s a brand new year, there’s no better time to have a go at something new.


Filed under: led hacks, musical hacks

Digital to Analog to Digital to Analog to Digital Conversion

อาทิตย์, 01/04/2015 - 13:00

[Andy] had the idea of turning a mixing desk into a MIDI controller. At first glance, this idea seems extremely practical – mixers are a great way to get a lot of dials and faders in a cheap, compact, and robust enclosure. Exactly how you turn a mixer into a MIDI device is what’s important. This build might not be the most efficient, but it does have the best name ever: digital to analog to digital to analog to digital conversion.

The process starts by generating a sine wave on an Arduino with some direct digital synthesis. A 480 Hz square wave is generated on an ATTiny85. Both of these signals are then fed into a 74LS08 AND gate. According to the schematic [Andy] posted, these signals are going into two different gates, with the other input of the gate pulled high. The output of the gate is then sent through a pair of resistors and combined to the ‘audio out’ signal. [Andy] says this is ‘spine-crawling’ for people who do this professionally. If anyone knows what this part of the circuit actually does, please leave a note in the comments.

The signal from the AND gates is then fed into the mixer and sent out to the analog input of another Arduino. This Arduino converts the audio coming out of the mixer to frequencies using a Fast Hartley Transform. With a binary representation of what’s happening inside the mixer, [Andy] has something that can be converted into MIDI.

[Andy] put up a demo of this circuit working. He’s connected the MIDI out to Abelton and can modify MIDI parameters using an audio mixer. Video of that below if you’re still trying to wrap your head around this one.


Filed under: Arduino Hacks, digital audio hacks

The Smallest Portable Pi

อาทิตย์, 01/04/2015 - 10:00

What do you get when you take an extremely small Raspberry Pi clone and stuff it inside a Game Boy Advance SP? We don’t know what to call it, but it’s probably one of the best portable gaming machines ever made, able to run emulators ranging from the Apple II to playing Quake III natively on a tiny flip-top display.

This isn’t the first time we’ve seen [frostedfires]’ work on a tiny system stuffed into a Game Boy. The initial post on this build over on the bacman forums just covered the basics – getting an Odroid W up and running, and putting Quake III on the tiny display. Now that the build is complete, we can get a look at what it takes to turn a Raspberry Pi clone into one of the smallest portable projects we’ve ever seen.

Using a Raspi clone as the only component in a tiny portable emulation station isn’t possible, so [frostefires] added a few other bits of electronics to make everything work. There’s a joystick from a PSP in there to work as the mouse, a few extra buttons in addition to the stock Game Boy ones, A USB hub, WiFi adapter, speaker and amplifier, a battery and the related charging electronics, and a Teensy 3.1 to handle all the input.

It’s a very impressive build that can run emulators ranging from the Apple II to later generation Nintendo consoles and handhelds (including the Game Boy Advance), but since the HDMI connector is availble on the outside of the case, [frostedfires] can also use this as a tiny, portable media center. Check out the video below to see this Game Boy in action, playing Mario Kart and 1080p video.


Filed under: nintendo gameboy hacks, Raspberry Pi

Boeing 777 from Manilla Folders, A 6+ Year Effort

อาทิตย์, 01/04/2015 - 07:00

The closer you look the more you will be in awe of this shockingly intricate 777 replica. The fully-articulating landing gear alone has over 2,000 parts and 200 hours of assembly, not even including the penny-sized tires with individually-cut lug nuts. All carved from manilla office folders by hand.

A high school art architecture class in 2008 inspired this build by teaching a few papercrafting techniques. When [Luca] got a hold of a precision Air India 777-300ER schematic, he started building this 5 foot long 1:60 scale model. His project has received a fair amount of media attention over the years, including some false reports that he was so focused on the build that he dropped out of college (he did, for 2 years, but for other reasons). 6.5 years in the making, [Luca] is rounding the homestretch.

The design is manually drawn in Illustrator from the schematics, then is printed directly onto the manilla folders. Wielding an X-acto knife like a watch-maker, [Luca] cuts all the segments out and places them with whispers of glue. Pistons. Axles. Clamps. Tie rods. Brackets. Even pneumatic hoses – fractions of a toothpick thin – are run to their proper locations. A mesh behind the engine was latticed manually from of hundreds of strands. If that was not enough, it all moves and works exactly as it does on the real thing.

Tires actually swing and steer. Landing gear actually collapses and folds up. The flaps move. The engines are not just magnificent static replicas; the 777 has a collapsible rear section for reverse thrust and so does [Luca]’s manilla version. The cabin and cargo doors hinge and lock into place. Even the bathrooms are just as cramped as you remember them being.

[Luca] spent a whole summer just on the furniture: the 300+ economy seats took him 20 minutes each, two business class seats could be finished in a day, and a single first class suite was a full 8 hour shift. The engines took another five months. The galley too has plenty of detail – row after row of carts and cabinets.

It is not just the precision, meticulousness, and detail that impresses – the infinitesimal scale defies belief. The individual cockpit controls are each dwarfed by the grooves of their maker’s fingerprints. See the video embedded below of the main landing gear retracting and note the whole assemblies manipulated by tweezers. Just like the real thing the gear is small but strong, it can support several times the weight of the finished jet.

Expecting to be complete later this year (though he said the same thing last year), [Luca] has already started painting the fuselage. After he is done he plans to one-up himself with a 20 foot version.

[Luca] does not have a project page per se but he documents well. He even spent two weeks editing 130 hours of time-lapse footage for his fans to appreciate the work that goes into a single assembly. For all the glorious details see his Flickr albums or his Youtube channel.

Thanks [Lars] for the tip.

* Corrected, it was an architecture class, not an art class.


Filed under: misc hacks, transportation hacks

Automatic 3D Scanning On The Cheap

อาทิตย์, 01/04/2015 - 04:00

After hearing about a few 3D object scanners, [Will] thought one of these tools could find a place in his workshop. The price of these scanners made him reconsider simply buying one, so he just made one out of parts that were sitting around. This was the first version of his 3D scanner. It worked, but there were a few shortcomings. [Will] had to rotate the object manually. That’s a cheap way of doing it, but the method is tedious.

Now [Will] is back for round two. He’s made some improvements, and this time a few bits of electronics automate the process, allowing [Will] to hit a button, walk away, and come back to a scanned object.

Even though [Will] has improved his setup immensely, the theory of how to scan an object remains the same. He’s projecting a straight vertical line on an object, taking a few snapshots with a webcam, and reconstructing the object with computer vision algorithms and Meshlab. The new additions include a BeagleBone Black, a stepper motor and an EasyDriver from Sparkfun, and a turntable.

[Will] wrote two scripts for this project. The first does the mechanical heavy lifting – turning the stepper motor and taking a picture, while the second converts the output from the webcam to a point cloud. From there, the point cloud is sent over to Meshlab, and an object appears on [Will]’s hard drive.

There’s about $80 in hardware invested in this setup, and considering the inspiration for this project was the $800 Makerbot Digitizer, we’re going to call [Will]’s experiments in 3D scanning a success.


Filed under: 3d Printer hacks

Peculiar Radial Mill from Car Parts

อาทิตย์, 01/04/2015 - 01:00

Whether 3D printer, lasercutter, or mill, most CNC machines use human-friendly, square-angle Cartesian geometry. This intriguing concept mill instead uses radial axes where motion is derived from scrap Chevy flywheels. It may look and feel weird at first, but it works – sort of.

Cartesian axes are intuitive. If you want to go to the right, increase X. If you want to go to away from you, increase Y. If you want to lift, increase Z. On a manual mill this is easy for making rectangles and blocks, or, with creative clamping, straight lines of any sort. But if you want to carve a circle? As we all learned on an Etch-A-Sketch, you increase your swearing and then throw it in the corner.

[Jason] knew that with a CNC machine all geometry problems are reduced to math done by software. With two offset discs, any position is possible by rotating both the correct way. It may look odd that both plates drunkenly meander about just to draw a straight line but the computer is ambivalent. Software can be complicated without penalty and is free once written – more on that later. If a machine is physically simple then it can be built and repaired easily and cheaply. This design does away with almost all the familiar – and [Jason] argues complicated – components of normal hobby CNC machines. No slides, rails, carriages or belts here. His design uses only about a dozen parts.

Because automotive flywheels are made from cast iron the machine is rigid and naturally dampening. Sticking with the junkyard theme he pulled bearings from an F-450 truck, good for a few thousand pounds. Some steppers and a Raspberry Pi and he was done – well, sort of.

[Jason] let us know that his project has sat for long enough that he has become passionate about other things and decided to move on. He documented his progress and submitted the tip in hope to inspire someone else to continue the design further. Any type of CNC is possible, not just a mill. 3D printer perhaps?

Two big caveats: it needs a Z-axis (linear, probably standard) and there appears to be deeper-seated-than-expected G-code demands to chit-chat about rectangles and only rectangles. Nothing insurmountable, just nothing he has solved yet himself.

[Jason] said not to expect any further updates from him but he would love to see what the next person could do with it.

See the video after the break of the mill drawing our skull and wrenches logo, (soft of, without a Z-axis to lift).


Filed under: car hacks, cnc hacks

Reverse Engineering the Kayak Mobile API

เสาร์, 01/03/2015 - 22:01

The travel meta-search website Kayak apparently used to have a public API which is no longer available. We can’t say we mourn the loss of the interface we’d never known about. If you are someone who was automating their searches for that perfect vacation getaway deal, there’s still hope. But either way you’ll like this one. [Shubhro Saha] figured out how to access the API used by the Kayak mobile app. We like that he details how to sniff the traffic between an app and the internet and make sense of what is found.

His tool of choice is the Python package Mitmproxy. We haven’t heard of it but we have heard of Wireshark and [Shabhro] makes the case that Mitmproxy is superior for this application. As the name suggests, you set it up on your computer and use that box’s IP as the proxy connection for your phone. After using the app for a bit, there is enough data to start deconstructing what’s going on between the app and remote server which which it communicates. We could have a lot of fun with this, like seeing what info those free apps are sending home, or looking for security flaws in your own creations.

[Thanks Juan via Twitter]


Filed under: Cellphone Hacks, security hacks

Sega Controller Hack Updated for Windows Auto-Launch

เสาร์, 01/03/2015 - 19:01

Who knew that modern versions of Windows have nixed the option to auto-launch when a USB drive is inserted? Not a big deal unless, like [sonicdude10], you want to base a hack on the behavior. He did find a workaround and recently built a Sega Controller emulator to autoplay on Windows computers.

The bulk of the hack was inspired by a Sega Emulator built in a controller which he saw on Hackaday a couple of years back. It’s simply a Sega-like USB gamepad which has a hub and thumb drive internalized. The hardware changes on [sonicdude10’s] version gets rid of the old thumb drive and replaces it with one that supports U3. This is a hardware emulation trick supported by some USB drives which allows them to enumerate as CD drives instead of USB mass storage. Autoplay for CD drives is still functional in Windows.

We’ve heard a bit about U3 over the years. There was a now-dead hack covered all the way back in 2006. And we even found a comment suggesting its use for USB-based game emulators. [sonicdude10] points to two useful tools that let him customize how U3 performs. u3_tool is a multitool for tweaking how the hardware behaves, u3-autorun makes customization of the auto-launching app a snap.


Filed under: peripherals hacks

Trinket EDC Contest: USB Calipers

เสาร์, 01/03/2015 - 16:00

[Lou]’s entry for the Trinket EDC Contest is a great addition to the ubiquitous digital calipers found on workbenches and eBay resellers the world over. It translates the value displayed on the calipers to a USB HID interface for logging all those tricky measurements at the push of a button.

Most of the digital calipers you’ll find at Harbor Freight or on eBay are pretty much the same. There are two pads on the caliper’s PCB that give any microcontroller the ability to read what is being measured. It’s done with a 24-bit encoding scheme, where each bit is a nearly-BCD measurement in units of 1/1000 of an inch or 1/100 of a millimeter. After decoding the value, [Lou]’s trinket sends a few numbers to a computer over a USB HID interface.

Simply sending a measurement to a computer over USB wasn’t enough for [Lou]. He added three buttons to the project for typing multiple characters. The first button just sends Enter to the computer, the second sends a comma, and the third sends “/2 (Enter)”, exactly what you need to input the radius of something when measuring the diameter.

This was a project for the Trinket EDC Contest that ended a few hours ago. Nobody knows who the winner is, but there are some pretty cool prizes up for grabs including the new Rigol scope, a Fluke 179, and a soldering station.


Filed under: contests, tool hacks

Shower Occupancy Sensor Keeps Peace/Eliminates Odor at the Office

เสาร์, 01/03/2015 - 13:01

When the first two prototype ingredients listed are paperclips and Post-it notes you know it’s going to be good. The problem: one shower stall at work with numerous co-workers who bike to the office. The solution: a occupancy monitor that is smart enough to know that someone is actually in the room. You know what we’re talking about, a sensor that knows more than whether the door is open or closed. [James] got wise and built a sensor to monitor whether the door is bolted or not. We think this method is far superior to motion-based systems.

This uber-smart sensor is simply a pair of paperclips anchored on a rolled Post-it note substrate and shoved in the receiver on the door jamb. When the bolt is locked from the inside it pushes the paperclips together completing the simple circuit. This is monitored by a Spark Core but will work with just about any monitoring system you can devise. What we’re trying to figure out is how to ruggedize the paper-clip hack which we can’t think will perform well for very long. It looks like there’s room to bore out a bit more inside the receiver hole. Perhaps leaf switch with a 3D printed mounting bracket?

Oh, and kudos on the Ikea food storage container for the enclosure. That’s one of our favorite tricks for hacks which are installed for the long-run.


Filed under: home hacks

Holiday Cheer From The ATtiny13

เสาร์, 01/03/2015 - 10:00

There are smaller microcontrollers than the ATtiny13. Some ARM chips will fit on the head of a large pin, and even in Atmel world, the ATtiny10 comes in a tiny SOT-23-6 package – a size normally reserved for surface mount transistors. The ‘tiny13, though, can be programmed with just about any ISP and comes in an 8-pin DIP. It’s the bare minimum if you’re looking to break out of the world of Arduino, and you can do some pretty cool things with it, like playing some holiday audio with an SPI Flash chip.

[Vinod] tried opening up a cheap camera pen, but in the course of disassembly a few traces broke. He was now left with a 4Mbit SPI Flash chip. This was obviously the time to investigate what could be done with a small microcontroller and a huge amount of Flash. and the Attiny13 audio player was born.

The circuit uses one PWM for audio out, and reads audio directly from the Flash chip. The UART on board the ‘tiny13 is used to update the Flash, and there’s also a switch to select between play and record. If you’re counting, that means there are 4 pins for the Flash, 2 pins for the UART, 1 for the switch, one for the audio output, and the power and ground rails, all in an 8-pin package. That’s a pretty cool way to use one pin for two different functions.

You can check out a video of the project in action below.


Filed under: ATtiny Hacks

The Ultimate Tool Cart

เสาร์, 01/03/2015 - 07:01

[Burning Becks] set out on a quest to build the ultimate tool cart for himself, and we have to admit, what he’s come up with is pretty damn cool. Not only is the cart super organized and functional, it has an integrated fingerprint scanner to unlock one door, a keypad to unlock another drawer, an RFid tag to unlock another… and an RF remote too. Excessive? Perhaps. But hey, what if you accidentally burn off all your finger prints while building a hotplate SMD reflow oven? It’s possible!

To build the ultimate tool cart, [Becks] had to do some research. Specifically research right here at Hackaday, since we love covering unique work benches and tool boxes. He’s taken a few ideas from some of our favorite work space hacks like the computer tower toolbox, a cyclist’s bicycle workshop (yes it’s actually mounted on the bicycle!), a travelling electronics lab, and of course the mobile soldering workstation that sets up quickly and lets you get to work fast.

Most of the build log is in German but Google translate does a pretty good job getting the point across. There are lots of pictures of the build process, and even a few videos. Unfortunately we can’t embed them, so you’ll have to click some links instead.

First up we have a demonstration of the fingerprint scanner, then a video showing the keypad in action, the RF remote, and a closeup on the latching mechanism for the RFid badge scanner.


Filed under: tool hacks

3D Printable LED Diffusors

เสาร์, 01/03/2015 - 04:00

While you can get an LED matrix in any size or shape, the really cool looking ones that are perfect for low-res displays all have diffusors. When they come from a nameless Chinese factory, these diffusors are thin sheets of plastic set into an extruded plastic frame. Since [Jan] has a 3D printer, he figured a custom diffusor was just a few bits of filament and a SCAD file away.

The basis for this custom LED diffusor was a LoL Shield given to [Jan] by the creator at the recent 31C3 conference. This shield is really only just 126 LEDs, multiplexed and in an Arduino form factor, and that many LEDs were just too bright and indistinct next to each other. The plan for a 3D printed diffusor was hatched.

After taking a few measurements, a pair of OpenSCAD files were whipped up and printed out. Assembly consisted of pressing 126 tiny little white diffusors into a frame, but once everything was attached to the matrix, the results were worth it.

Check out the video below for the before and after, demonstrating what a few bits of plastic can do to a LED matrix.


Filed under: 3d Printer hacks, led hacks

Hacklet 28 – Programmable Logic Hacks

เสาร์, 01/03/2015 - 01:00

FPGAs, CPLDs, PALs, and GALs, Oh My! This week’s Hacklet focuses on some of the best Programmable Logic projects on Hackaday.io! Programmable logic devices tend to have a steep learning curve.  Not only is a new hacker learning complex parts, but there are entire new languages to learn – like VHDL or Verilog. Taking the plunge and jumping in to programmable logic is well worth it though. High-speed projects which would be impossible with microcontrollers are suddenly within reach!

A great example of this is [Tom McLeod’s] Cheap FPGA-based HDMI Experimenting Board. [Tom’s] goal was to create a board which could output 720p video via HDMI at a reasonable frame rate. He’s using a Xilinx Spartan 6 chip to do it, along with a handful of support components. The images will be stored on an SD card. [Tom] is hoping to do some video with the setup as well, but he has yet to see if the chip will be fast enough to handle video decoding while generating the HDMI data stream. [Tom] has been quiet on this project for a few months – so we’re hoping that either he will see this post and send an update, or that someone will pick up his source files and continue the project!

Next up is our own [technolomaniac] with his Arduino-Compatible FPGA Shield. Starting out with FPGAs can be difficult. [Technolomaniac] has made it a bit easier with this shield. Originally started as a project on .io and now available in The Hackaday Store, the shield features a Xilinx Spartan 6 FPGA. [Technolomaniac] made power and interfacing easy by including regulators and level shifters to keep the sensitive FPGA happy. Not sure where to start? Check out [Mike Szczys’] Spartan-6 FPGA Hello World! [Mike] takes us from installing Xilinx’s free tool chain to getting a “hello world” led blinker running!

Still interested in learning about Programmable Logic, but not sure where to go? Check out [Bruce Land’s] Teaching FPGA parallel computing. Actually, check out everything [Bruce] has done on Hackaday.io – the man is a living legend, and a wealth of information on electronics and embedded systems. Being a professor of engineering at New York’s Cornell University doesn’t hurt either! In Teaching FPGA parallel computing, [Bruce] links to Cornell’s ECE 5760 class, which he instructs. The class uses an Altera/Terasic DE2 FPGA board to demonstrate parallel computing using programmable logic devices. Note that [Bruce] teaches this class using Verilog, so all you seasoned VHDL folks still can learn something new!

 

Finally, we have [Michael A. Morris] with Chameleon. Chameleon is an Arduino compatible FPGA board with a Xilinx Spartan 3A FPGA on-board. [Michael] designed Chameleon for two major purposes:  soft-core processors, and intelligent serial communications interface. On the processor side Chameleon really shines. [Michael] has implemented a 6502 core in his design. This means that it would be right at home as the core of a retrocomputing project. [Michael] is still hard at work on Chameleon, he’s recently gotten fig-FORTH 1.0 running! Nice work [Michael]!

Want more programmable logic goodness? Check out our Programmable Logic List!

That about wraps things up for this episode of The Hacklet! As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!


Filed under: FPGA, Hackaday Columns

Prototyping With The ATMega1284P

ศุกร์, 01/02/2015 - 22:00

While most people are moving onto ARMs and other high-spec microcontrollers, [Dave Cheney] is bucking the trend. Don’t worry, it’s for a good reason – he’s continuing work on one of those vintage CPU/microcontroller mashups that implement an entire vintage system in two chips.

While toying around with the project, he found the microcontroller he was using, the ATMega1284p, was actually pretty cool. It has eight times the RAM as the ever-popular 328p, and twice as much RAM as the ATMega2560p found in the Arduino Mega. With 128k of Flash, 4k of EEPROM, 32 IOs, and eight analog inputs, it really starts to look like the chip the Arduino should have been built around. Of course historical choices don’t matter, because [Dave] can just make his own 1284p prototyping board.

The board is laid out in Fritzing with just a few parts including a crystal, a few caps, an ISP connector, and pins for a serial connector. Not much, but that’s all you need for a prototyping board.

The bootloader is handled by [Maniacbug]’s Mighty 1284 Arduino Support Package. This only supports Arduino 1.0, not the newer 1.5 versions, but now [Dave] has a great little prototyping board that can be put together from perfboard and bare components in a few hours. It’s also a great tool to continue the development of [Dave]’s Apple I replica.


Filed under: Microcontrollers

A Bluetooth Garage Door, Take Three

ศุกร์, 01/02/2015 - 19:00

A few years ago, [Lou] came up with a pretty clever build to open his garage door with his phone. He simply took a Bluetooth headset, replaced the speaker with a transistor, and tied the transistor to a few wires coming out of his garage door opener. When the Bluetooth headset connected, the short beep coming from the speaker output opened the door.

The newest version of this build does away with the simple Bluetooth headset and replaces it with a Bluetooth 4.0 chip. The reason for this is that Apple and their walled garden of an App store would never allow a Samsung Bluetooth headset to be used with one of their iDevices.

The latest build is just about as simple as using a Bluetooth headset. A board that appears to use TI’s CC2540 chip is attached to the garage door opener with a few passives and a transistor. Pairing the new circuit with a phone is as simple as shorting a pair of pins, and the new iOS app does exactly what it should – opens a garage door at the press of a non-button.

While it’s not something that can be put together with scraps from a junk drawer, it’s still an extremely simple solution to opening a garage door with a phone. Video below.


Filed under: wireless hacks