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Hackaday Prize Entry: The Internet Of Meat

พุธ, 09/21/2016 - 12:00

We’ve only just begun to see the proliferation of smart kitchen gadgets. Dumb crock pots with the intelligence of a bimetallic strip, are being replaced by smart sous vide controllers. The next obvious step is barbecue. For his Hackaday Prize entry, [armin] is building a smart, eight-channel BBQ controller for real barbecue, with smoke and fans, vents and metal boxes.

This BBQ controller has been in the works for years now, starting with a thread in a German barbeque forum. The original build featured an original Raspberry Pi, and could relay temperatures from inside a slab of meat to anywhere with range of a WiFi network.

For his Hackaday Prize entry, [armin] is working on a vastly improved version. The new version supports eight temperature probes, temperature logging and plotting, a webcam, setting alarms, a web interface, 433MHz radio, and PWM and fan control. Yes, if you’re very, very clever you can use this project to build a barbeque that will cycle a fan, and open and close a damper while monitoring the temperature of a brisket and email you when it’s done. It’s the Internet of Meat, and it’s the most glorious thing we’ve seen yet.

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Filed under: The Hackaday Prize

Arcade Button Pressing Game

พุธ, 09/21/2016 - 09:00

When every month brings out a fresh console blockbuster game that breaks new boundaries of cinematic immersion in its gameplay, it’s easy to forget that sometimes the simplest of game interfaces can be rewarding.

Hele Norges Knapp” (“All of Norway’s Button”), is a good example. As you might expect, it’s a button, a large arcade-style one, and the gameplay is simple. Press the button as many times as you can in 30 seconds. It’s a project from Norwegian Creations, and it was produced as a promotion that toured the country for one of Norway’s debit card payment systems.

The blog post and video is frustratingly light on hardware or software details, and their is nothing about it in their GitHub presence. But they tell us that at its heart is a Teensy 3.2 with an audio board, driving the big 7-segment displays for the scoreboard and the WS2801 LED lighting.

The button itself is Adafruit’s 100mm Massive Arcade Button, and given that it was pressed over a million times by eager Norwegians it would seem this project has proved its robustness.

The video below the break has details of construction and of the game in action, and there is another far more corporate promotional video on Facebook featuring a host of Bright Young People honing their button action in a sun-kissed Norway that looks almost tropical. The game itself does look as though it could be an amusing diversion in the same vein as those fairground strength tests.

There hasn’t been anything quite like this game here before. We think it would make a great festival installation, like Fire Pong, or the life-size Katamari Damacy ball.


Filed under: hardware

Classing Up a RetroPie Arcade With a Wine Barrel

พุธ, 09/21/2016 - 06:00

Arcade cabinets are a lot of fun, and something most of us would probably like in our homes. Unfortunately, space and decor constraints often make them impractical. Or, at least, that’s what our significant others tell us. Surely there must be a workaround, right?

Right! In this case, the workaround [sid981] came up with was to build a RetroPie arcade into a fancy looking wine barrel. The electronics are pretty much what you’d expect for a RetroPie system, and the screen is set into the top of the barrel. Control is handled by a wireless controller that can be tucked away when it’s not in use, and a glass top simultaneously protects the screen and lets guests use the barrel as a bar table.

Overall, it’s a really classy alternative to putting an arcade cabinet in the corner, and has the added benefit of doubling as a handy place to put your drinks. We’ve seen nifty builds in the past that accomplish a similar goal using coffee tables, but we think the aesthetic appeal of the wine barrel makes this a pretty awesome choice too.

[via r/diy]


Filed under: home entertainment hacks

LEGO Looper Makes Modular Music

พุธ, 09/21/2016 - 03:00

This LEGO synth made by [Rare Beasts] had us grinning from ear to ear.

It combines elements from LEGO Mindstorms with regular blocks in order to make music with color. A different music sample is assigned to each of five colors: red, blue, green, yellow, and white. The blocks are attached to spokes coming off of a wheel made with NXT an EV3. As the wheel turns, the blocks pass in front of a fixed color sensor that reads the color and plays the corresponding sample. The samples are different lengths, so changing the speed of the wheel makes for some interesting musical effects.

As you’ll see in the short video after the break, [Rare Beasts] starts the wheel moving slowly to demonstrate the system. Since the whole thing is made of LEGO, the blocks are totally modular. Removing a few of them here and there inserts rests into the music, which makes the result that much more complex.

LEGO is quite versatile, and that extends beyond playtime. It can be used to automate laboratory tasks, braid rope, or even simulate a nuclear reactor. What amazing creations have you made with it? Let us know in the comments.


Filed under: musical hacks

MakerBot Releases Their 6th Generation Of 3D Printers

พุธ, 09/21/2016 - 01:45

Just in time for the back to school and holiday season, Makerbot has released their latest line of printers. The latest additions to the lineup include the new Makerbot Replicator+ and the Makerbot Replicator Mini+.

The release of these new printers marks MakerBot’s first major product release since the disastrous introduction of the 5th generation of MakerBots in early 2014. The 5th generation of MakerBots included the Replicator Mini, priced at $1300, the Replicator, priced at $2500, and the Replicator Z18, priced at $6500. Comparing the build volume of these printers with the rest of the 3D printer market, these printers were overpriced. The capabilities of these printers didn’t move many units, either (for instance, the printers could only print in PLA). Makerbot was at least wise enough to continue building the 4th generation Replicator 2X, a printer that was capable of dual extrusion and printing more demanding filaments.

The release of the Makerbot Replicator+ and the Makerbot Replicator Mini+ is the sixth generation of MakerBot printers and the first generation of MakerBot’s manufactured overseas. This new generation is a hardware improvement on several fronts and included a complete redesign of the Makerbot Replicator and the Replicator Mini. The Replicator Mini+ features a 28% larger build volume than the original MakerBot Replicator Mini and an easily removable Grip Build Surface that can be flexed to remove a printed part. The Replicator+ features a 22% larger build volume than the MakerBot Replicator and a new Grip Build Surface. The Replicator Mini+ is $1000 ($300 cheaper than its predecessor), and the Replicator+ is $2000 ($500 less expensive). Both new printers, and the old Replicator Z18, now ship with the improved Smart Extruder+.

While the release of two new MakerBots does mean new hardware will make it into the wild, this is not the largest part of MakerBot’s latest press release. The big news is improved software. Makerbot Print is a slicer that allows Windows users to directly import 3D design files from SolidWorks, IGES, and STEP file formats. Only .STL files may be imported into the OS X version of the Makerbot Print software. MakerBot Mobile, an app available through the Apple Store and Google Play, allows users to monitor their printer from a smartphone.

Earlier this year, we wrote the Makerbot Obituary. From the heady days of The Colbert Report and an era where 3D printing would solve everything, MakerBot has fallen a long way. In the first four months of 2016, MakerBot only sold an average of about fifteen per day, well below the production estimated from the serial numbers of the first and second generation Makerbots, the Cupcake and Thing-O-Matic.

While this latest hardware release is improving the MakerBot brand by making the machines more affordable and giving the software some features which aren’t in the usual Open Source slicers, it remains to be seen if these efforts are enough. Time, or more specifically, the Stratasys financial reports, will tell.


Filed under: 3d Printer hacks, news

Expose your Raspberry Pi on Any Network

พุธ, 09/21/2016 - 00:01

Everyone’s talking about the Internet of Things (IoT) these days. If you are a long-time Hackaday reader, I’d imagine you are like me and thinking: “so what?” We’ve been building network-connected embedded systems for years. Back in 2003, I wrote a book called Embedded Internet Design — save your money, it is way out of date now and the hardware it describes is all obsolete. But my point is, the Internet of Things isn’t a child of this decade. Only the name is.

The big news — if you can call it that — is that the network is virtually everywhere. That means you can connect things you never would have before. It also means you get a lot of data you have to find a reason to use. Back in 2003, it wasn’t always easy to get a board on the Internet. The TINI boards I used (later named MxTNI) had an Ethernet port. But your toaster or washing machine probably didn’t have a cable next to it in those days.

Today boards like the Raspberry Pi, the Beagle Bone, and their many imitators make it easy to get a small functioning computer on the network — wired or wireless. And wireless is everywhere. If it isn’t, you can do 3G or 4G. If you are out in the sticks, you can consider satellite. All of these options are cheaper than ever before.

The Problem

There’s still one problem. Sure, the network is everywhere. But that network is decidedly slanted at letting you get to the outside world. Want to read CNN or watch Netflix? Sure. But turning your computer into a server is a little different. Most low-cost network options are asymmetrical. They download faster than they upload. You can’t do much about that except throw more money at your network provider. But also, most inexpensive options expose one IP address to the world and then do Network Address Translation (NAT) to distribute service to local devices like PCs, phones, and tablets. What’s worse is, you share that public address with others, so your IP address is subject to change on a whim.

What do you do if you want to put a Raspberry Pi, for example, on a network and expose it? If you control the whole network, it isn’t that hard. You usually use some kind of dynamic DNS service that lets the Pi (or any computer) tell a well-known server its current IP address (see figure below).

That well-known server answers DNS requests (the thing that converts hackaday.com into a real IP address). Now anyone can find your Pi. If you have a firewall in hardware and/or software (and it is a good bet that you do), you’ll also have to open the firewall port and tell the NAT router that you want to service traffic on the given port.

Alien Networks

That’s fine if you are at home and you control all of your network access and hardware. But suppose you don’t know for sure where your system will deploy. For example, perhaps you will use your box at different traffic intersections over a 3G modem. Or maybe you have built a smart picture frame to put in a hospital or nursing home and you want access over the institution’s WiFi.

Granted, you can handle that as a system design problem. For the hypothetical picture frame, maybe it checks a web server on the public Internet periodically for new content. Sure. You can do that. Until you need to ssh into the box to make some updates. Sometimes you just need to get to the box in question.

Solutions

There are a few options for cases like this. NeoRouter has software for many platforms that can create a virtual private network (VPN) that appears to be a new network interface where all the participants are local. If my desktop computer has a NeoRouter IP of 10.0.0.2 and my Pi has 10.0.0.9 then I can simply ssh over to that IP address. It doesn’t matter if the Pi is halfway around the world. The traffic will securely traverse the public Internet as though the two computers were directly connected with no firewalls or anything else between them.

Honestly, that sounds great, but I found it a little difficult to set up. It also isn’t terribly useful by itself. You need to run some kind of server like a Web server. You also need a NeoRouter server on the public Internet with an open port.

A Better Answer

What I wound up using was a service called Pagekite. The software is all open source and there is a reasonable amount of free use on their servers. I would go on to set the whole thing up on my own servers (I’ll talk about that next time). For right now, though, assume you are happy to use their server.

If you go to the Pagekite web site, they have a really simple “flight plan” to get you started:

curl -s https://pagekite.net/pk/ | sudo bash pagekite.py 80 yourname.pagekite.me

That’s it. Honestly, you don’t know these guys so I wouldn’t suggest just piping something off the Internet into my root shell. However, it is safe. To be sure I actually redirected the script from curl into a temporary file, examined it, and then ran it. You may be able to install Pagekite from your repository, but it might be an older version. They also have common packages on GitHub and repos for many package systems (like deb packages and RPM).

The concept behind PageKite is that of a reverse proxy. Both the remote computer and the user find the PageKite computer via DNS (see figure below). That server acts as a go-between and since nearly all networks will allow access to a web server, there should be no firewall issues.

The last line sets up a redirect from the specified URL to your local machine on port 80. So far that isn’t much different than using NeoRouter. However, the pagekite script is kind of interesting. It can be a backend (that is, your Raspberry Pi serving up web content), or a frontend (like the server at yourname.pagekite.me). It also has a simple web server in it. So if you wanted to serve out pages from, say /home/pi/public_html you could write:

pagekite.py /home/pi/public_html yourname.pagekite.me +Indexes

There is a way to add things like this so they start when pagekite starts (read about the –add option). It all works and it works well.

You can redirect other ports, also. There is even a way to tunnel SSH traffic, although it does require a proxy set up for the SSH client. That will depend on what ssh programs you use. Although it is a bit of trouble, it is also handy since it allows you to SSH into the remote box even on restrictive work or school networks.

Pagekite will give you a chance to sign up the first time you run the script. However, you do need to be on a machine that can open a browser, so if you are using your Pi headless, you might want to set up the account first on another machine.

The free account has some limits, but it does let you set up a CNAME to redirect from your own domain name. You can also create unlimited subdomains (e.g., toaster.myiot.pagekite.me, washer.myiot.pagekite.me, and alarmsystem.myiot.pagekite.me).

On Your Own

If you don’t have a public computer and you don’t have a lot of data transfer needs, the Pagekite free plan might just work for you. I didn’t want to use their domain or be subject to their quotas, so I decided to install the frontend to my own web server. The code is open source, but the documentation for making that work is not great.

Luckily, next time, I’ll take you through the steps I took to get it all working. It isn’t that hard, but it does require a little thought, text editing, and DNS dexterity.


Filed under: Hackaday Columns, internet hacks, Original Art, Raspberry Pi, Skills

RC Drag Racing Christmas Tree and Speed Trap

อังคาร, 09/20/2016 - 22:30

In the drag racing world, a Christmas tree is the post at the start line that sequentially lights up a set of yellow lights followed shortly after by a green light to tell the drivers to go, the lights obviously giving it its seasonal name. Included at the base of the tree are lasers to detect the presence of the cars.

[Mike] not only made his own Christmas tree for his RC cars, but he even made an end-of-track circuit with LED displays telling the cars how long they took. Both start and finish hardware are controlled by Pololu Wixel boards which has TI CC2511F32 microcontrollers with built-in 2.4 GHz radios for wireless communications.

In addition to the LEDs, the Christmas tree has a laser beam using a 650nm red laser diode for each car at the start line that’s aimed at a TEPT5600 phototransistor. If a car crosses its beam before the green light then a red light signals the car’s disqualification.

The end-of-track circuit has 7-segment displays for each car’s time. [Mike] designed the system so that the Christmas tree’s microcontroller tells the end-of-track circuit’s microcontroller when to reset the times, start the times, and clear the times should there be a disqualification. The finish line controller has lasers and phototransistors just like the starting line to stop the timers.

Oh, and did we mention that he also included 1980’s car racing game sounds? To see and hear it all in action check out the video after the break. If the cars seem a little drunk it’s because pushing left or right on the controller turns the wheel’s fully left or right.


Filed under: misc hacks, wireless hacks

Ask Hackaday: Help Me Choose A ‘Scope

อังคาร, 09/20/2016 - 21:00

If there is one instrument that makes an electronic engineer’s bench, it is the oscilloscope. The ability to track voltages in the time domain and measure their period and amplitude is one akin to a light in the darkness, it turns a mere tinkerer with circuits into one in command of them. Straightforward add-on circuits can transform a basic oscilloscope into a curve tracer, frequency response display, and much more, and modern oscilloscopes offer a dizzying array of useful measurement features unimaginable to engineers only a few years ago. And I need your help to pick a new one.

They don’t make ’em like they used to! My Cossor portable oscillograph. The Status Quo

My first oscilloscope came my way in the early 1980s when my school had a lab clear-out. It’s a dual-beam Cossor, probably from the 1950s, and it proudly boasts a 2MHz – or should I say “2 Mc/s”! – bandwidth. The maker’s plate calls it a “Portable Oscillograph”, because it does have a handle on top and if you are a weight-lifter you can probably carry it some distance. Dusting it off from the garage recesses for this article brought back memories of all those hacked-together circuits made from old TV parts, of seeing for myself the mysteries of the PAL colour burst, and of my home-made spectrum analyser.

The Cossor clearly wasn’t going to cut it for an electronic engineering student, so sometime about 1990 I made the trip to the Aladdin’s Cave  of Stewarts of Reading, and bought a bargain Gould dual-scan ‘scope from the mid 1970s. It has a 20MHz bandwidth, and has been my trusty companion ever since. It’s typical of everyday ‘scopes of the era, and since ‘scopes like it can be found for little more than beer money these days I’d have no hesitation recommending one to anybody looking for a basic piece of test equipment.

A quarter century later though, I have a ‘scope problem. As a radio amateur I’ve always wrestled with the Gould’s low bandwidth. It’s also not the smallest of instruments, and the sheer number of things new ‘scopes can do these days are something I just can’t ignore. It’s time I bought a new ‘scope, and this is where you come in.

Choices, Choices

If I held my finger over the badge, would you be able to distinguish it from its competition? Image: SIGLENT TECHNOLOGIES CO.,LTD [PD], via Wikimedia CommonsTo narrow down the selection a little, consider that I won’t be able to spend thousands of pounds on the ‘scope I’d really like. The people who sell ‘scopes at the top of the market will have to wait for my ship to come in. And USB ‘scopes aren’t my thing, I prefer a stand-alone instrument.

Instead I will be looking where I suspect a lot of you will too, at the lower-end Chinese digital ‘scopes from brands like Rigol, Owon, Siglent, Hantek, and others. I’m very familiar with more than one of them from use in contracts, hackspaces, and other people’s benches. They are all compact instruments with fairly similar specifications between brands, in fact many models look similar enough to have been made on the same production lines. They will not perhaps have the spec of the multi-thousand-pound ‘scope when it comes to the edges of the envelope in noise or even sensitivity, but the performance they deliver for the price is more than enough for my purposes.

Why buy a DS1074 when a DS1054 will do. Image: Alex P. Kok (Own work) [CC BY-SA 4.0], via Wikimedia Commons.So given an array of outwardly similar ‘scopes which still occupy a range of prices over the budget end of the market, how should I choose? Once I’ve made the decision that I only need 2 channels rather than 4, my basic requirement above all else is for bandwidth, so that seems a good place to start. But even there the picture is muddled, it seems to be the norm for these instruments to have a quoted bandwidth which can be extended with a software hack. Most well-known are the Rigol 1050 series, 50MHz ‘scopes which can achieve 100MHz bandwidth, but they not alone by any means. Perhaps the manufacturers permit such illicit upgrades because they are a valuable sales tool. My gut feeling though is to buy the highest bandwidth ‘scope I can afford and see a later upgrade as a bonus, but not necessarily to do it straight away as I prefer my instruments unbricked and with warranties.

Even homing in on the bandwidth doesn’t give me as clear a picture as it should. For somewhere between £200 and £300 (About $260 to $400) when all taxes are paid, I can buy any of a spread of Chinese 2-channel 100MHz ‘scopes with similar spec. Some of the models even promise a bonus 200MHz upgrade with a software hack, but this is not price-dependent. I’m left looking at differences in the length of the sample memory, and even wondering whether I am sometimes simply being expected  to pay a bit extra to support an emerging brand hierarchy.

The Hackaday readership are a diverse group, among whom alongside the interested readers reside real, not armchair, experts on almost any subject we cover. Some of you will be in my position of looking at new ‘scopes, and many of you will have been through this process yourselves and have the tales both good and bad to tell about your choices. So if you were standing where I am and looking at a budget digital ‘scope, what would inform your choices?

Header images: Binarysequence (Own work) [CC BY-SA 3.0], via Wikimedia Commons


Filed under: Ask Hackaday, Hackaday Columns

Absolute 3D Tracking With EM Fields

อังคาร, 09/20/2016 - 18:01

[Chris Gunawardena] is still holding his breath on Valve and Facebook surprising everyone by open sourcing their top secret VR prototypes. They have some really clever ways to track the exact location and orientation of the big black box they want people to strap to their faces. Until then, though, he decided to take his own stab at the 3D tracking problems they had to solve. 

While they used light to perform the localization, he wanted to experiment with using electromagnetic fields to perform the same function. Every phone these days has a magnetometer built in. It’s used to figure out which way is up, but it can also measure the local strength of magnetic fields.

Unfortunately to get really good range on a magnetic field there’s a pesky problem involving inverse square laws. Some 9V batteries in series solved the high current DC voltage source problem and left him with magnetic field powerful enough to be detected almost ten centimeters away by his iPhone’s magnetometer.

As small as this range seems, it ended up being enough for his purposes. Using the existing math and a small iOS app he was able to perform rudimentary localization using EM fields. Pretty cool. He’s not done yet and hopes that a more sensitive magnetometer and a higher voltage power supply with let him achieve greater distances and accuracy in a future iteration.


Filed under: Virtual Reality, wearable hacks

An ESP8266 in Every Light Switch and Outlet

อังคาร, 09/20/2016 - 15:01

[Hristo Borisov] shows us his clever home automation project, a nicely packaged WiFi switchable wall socket. The ESP8266 has continuously proven itself to be a home automation panacea. Since the ESP8266 is practically a given at this point, the bragging rights have switched over to the skill with which the solution is implemented. By that metric, [Hristo]’s solution is pretty dang nice.

It’s all based around a simple board. An encapsulated power supply converts the 220V offered by the Bulgarian power authorities into two rails of 3.3V and 5V respectively. The 3.3V is used for an ESP8266 whose primary concern is the control of a triac and an RGB LED. The 5V is optional if the user decides to add a shield that needs it. That’s right, your light switches will now have their own shields that decide the complexity of the device.

The core module seen to the right contains the actual board. All it needs is AC on one side and something to switch or control on the other The enclosure is not shown (only the lid with the shield connectors is seen) but can be printed in a form factor that includes a cord to plug into an outlet, or with a metal flange to attach to an electrical box in the wall. The modules that mate with the core are also nicely packaged in a 3D printed shield. For example, to convert a lamp to wireless control, you use a shield with a power socket on it. To convert a light switch, use the control module that has a box flange and then any number of custom switch and display shields can be hot swapped on it.

It’s all controllable from command line, webpage, and even an iOS app; all of it is available on his GitHub. We’d love to hear your take on safety, modularity, and overall system design. We think [Hristo] has built a better light switch!


Filed under: home hacks

Hackaday Prize Entry: Mouse Controlled Microscope

อังคาร, 09/20/2016 - 12:00

You might imagine that all one should need to operate a microscope would be a good set of eyes. Unfortunately if you are an amputee that may not be the case. Veterinary lab work for example requires control of focus, as well as the ability to move the sample in both X and Y directions, and these are not tasks that can easily be performed simultaneously with only a single hand.

[ksk]’s solution to this problem is to use geared stepper motors and an Arduino Mega to allow the manual functions of the microscope to be controlled from a computer mouse or trackball. The motors are mounted on the microscope controls with a custom 3D-printed housing. A rotary selector on the control box containing the Arduino allows the user to select a slow or fast mode for fine or coarse adjustment.

It’s fair to say that this project is still a work in progress, we’re featuring it in our series of posts looking at Hackaday Prize entries. However judging by the progress reported so far it’s clear that this is a project with significant potential, and we can see the finished product could be of use to anyone operating the microscope.

We’ve featured one or two mouse controlled projects over the years, though not controlling microscopes. Here’s one mouse controlled robot arm, and we’ve covered another arm with a 3D mouse.

The HackadayPrize2016 is Sponsored by:
Filed under: hardware, The Hackaday Prize

The Cicada: A Parasite Art Piece With Commitment Issues

อังคาร, 09/20/2016 - 09:00

How often do you think deeply about the products around you? How about those you owned five years ago? Ten? The Cicada — brainchild of [Daniel Kerris] — is an art piece that aims to have the observer reflect on consumer culture, buyer’s remorse, and wanting what we cannot have.

The Cicada consists of an ultrasonic sensor feeding data to a Raspberry pi which — calculating the distance of an approaching human — either speeds up or slows down a servo motor connected to a General Electric Walkman’s cassette speed potentiometer. Upon detecting someone approaching, The Cicada begins to loop the chorus of Celine Dion’s “I Will Always Love You”. As you move closer, the tape speed slows, and there is a transition from love at first sight to nightmarish drawl as the music slows.

Of course as you leave, it begins to play at normal speed again. [Kerris] hopes this will induce the observer to reflect on wanting what we can’t have — especially if it’s the ‘greener’ grass on the other side of the fence — but also about the media we consume: how we view it, how that initial state changes over time, and — at the very least — how to recycle old tech into new projects!

If you’re looking for more tech-art, The Cicada would be at home in this creepy mechanical art show.

 


Filed under: misc hacks, Raspberry Pi

Thermoelectric Dry Ice Generator Does Not Work (Yet)

อังคาร, 09/20/2016 - 06:00

[Pabr] is trying to make dry ice the hard way by building a thermoelectric dry ice generator. The project is a well planned round trip through thermodynamics and cryogenics with a hard landing on the icy grounds of trial and error.

[Pabr’s] four stage Peltier element on a heatsink.While dry ice can be obtained with simpler methods, for example by venting gaseous CO2 from fire extinguishers and collecting the forming CO2 flakes, [pabr’s] method is indeed attractive as a more compact solid-state solution. The setup employs a four stage Peltier element, which uses four Peltier stages to achieve a high temperature differential. With sufficient cooling on the high-temperature side of the element, it should be well capable of achieving temperatures below -78.5 °C, the sublimation temperature of CO2. So far, [pabr] has built three different setups to expose small amounts of CO2 to the cold of the Peltier element, hoping to observe the formation of little dry ice flakes.

The first setup placed the Peltier element on a massive heatsink, which itself was placed in ice water. A chamber around the element was flooded with CO2 from a bicycle tire inflator. Dry ice was expected to form on the cold tip of the element, but unfortunately, nothing happened. The second attempt was to attach a liquid cooling system with a capable radiator and again, filled with ice water, to the high-temperature side of a Peltier element. A plausible attempt, but again, no success in dry ice production. The third setup moved the experiment to a quasi-vacuum chamber, where CO2 could be streamed onto the Peltier element through a fine needle. The low-pressure environment may have helped with the thermal insulation of the setup, but it also lowers the sublimation temperature of CO2 down to -100 °C. And once again, no CO2 snow formed.

This is not the end of this project, and [pabr] is still working his way toward thermoelectric dry ice production. One big challenge is the acquisition of capable measuring equipment. Thermocouples that are specified for cryogenic temperatures are expensive, and until now measurements have only been taken on the high-temperature side of the cooling element – relying on datasheet values to get an idea of what’s happening on the cold side. Do you have a good idea on how to make this work? [Pabr] will appreciate your suggestions, so let us know in the comments!


Filed under: misc hacks

“Smilemachine” Helmet is a Delightful Mixture of Tech

อังคาร, 09/20/2016 - 03:00

Part performance art and part social experiment, [mocymo]’s Smilemachine V6 helmet is as delightful as it is expressive. The helmet is made primarily from laser-cut MDF assembled around parts from a safety helmet. The display is an Android tablet with fine operation controlled by a Bluetooth mini keyboard, and the helmet cleverly makes use of the tablet’s ability to adjust the display to compensate for head tilt angle. It recently made an appearance at Maker Faire Tokyo, where the creator says the reception (especially by children) exceeded expectations.

There are several interesting things done with this device. One is the handheld controller, which is essentially a mini Bluetooth keyboard. To help allow fine control without needing to look down at the controller, the keyboard sits in a frame with some nuts and bolts used as highly tactile button extensions. By allowing the user to change the physical button layout (and setting up keyboard shortcuts on the device to match) the arrangement can be made more intuitive for the user. Some photos of this assembly are in the gallery after the break.

Geared mirrors to allow seeing out the front of the helmet.

Another interesting bit is that despite a tablet being right in front of your eyes, it is possible to see out the front of the helmet while wearing it. The solution is completely low-tech: two mirrors form a periscope whose angle can be adjusted by turning a knob on the side of the helmet.

Version 1 of the helmet was started back in 2012; this is version 6 and [mocymo] is already filling out a to-do list for refinements. The nose area is uncomfortable, the angle of periscope is slightly off and the gearing needs to be reworked, among other things. We can’t wait to see Version 7. Video and gallery are embedded below.

 

Whenever you are building something into a helmet, every little bit of space matters so it’s important to use whatever you can to save space and weight. For example, offloading the controls in this iPhone-controlled Daft Punk helmet means less to fit into the helmet itself. But sometimes you have no alternative but to design everything as smartly as you can, like this Iron Man Helmet’s faceplate-locking assembly, or this Stargate Horus helmet.


Filed under: misc hacks

Amateur Radio Parity Act Passes US House

อังคาร, 09/20/2016 - 01:31

Most new houses are part of homeowners associations, covenants, or have other restrictions on the deed that dictate what color you can paint your house, the front door, or what type of mailbox is acceptable. For amateur radio operators, that means neighbors have the legal means to remove radio antennas, whether they’re unobtrusive 2 meter whips or gigantic moon bounce arrays. Antennas are ugly, HOAs claim, and drive down property values. Thousands of amateur radio operators have been silenced on the airwaves, simply because neighbors don’t like ugly antennas.

Now, this is about to change. The US House recently passed the Amateur Radio Parity Act (H.R. 1301) to amend the FCC’s Part 97 rules of amateur stations and private land-use restrictions.

The proposed amendment provides, ““Community associations should fairly administer private land-use regulations in the interest of their communities, while nevertheless permitting the installation and maintenance of effective outdoor Amateur Radio antennas.” This does not guarantee all antennas are allowed in communities governed by an HOA; the bill simply provides that antennas, ‘consistent with the aesthetic and physical characteristics of land and structures in community associations’ may be accommodated. While very few communities would allow a gigantic towers, C-band dishes, or 160 meters of coax strung up between trees, this bill will provide for small dipoles and inconspicuous antennae.

The full text of H.R. 1301 can be viewed on the ARRL site. The next step towards making this bill law is passage through the senate, and as always, visiting, calling, mailing, faxing, and emailing your senators (in that order) is the most effective way to make views heard.


Filed under: news, radio hacks

Grinding Gears: Figuring Out The Ratio

อังคาร, 09/20/2016 - 00:01

Practically any combination of motor and gearbox can be mathematically arranged to fit all sorts of problems. You could lift a crane with a pager motor, it just might take a few hundred years. However, figuring out exactly what ratio you need can feel bit backwards the first time you have to do it.

A gear is nothing more than a clever way to make two circles rotate in concert with each other as if they were perfectly joined at their circumferences. Rather than relying on the friction between two rotating disks in contact, the designer instead relies on the strength of a gear tooth as the factor limiting the amount of torque that can be applied to the gear.

Everything is in gearing is neatly proportional. As long as your point of reference is correct, and some other stuff. Uh, it gets easier with practice.

Now as my physics professors taught me to do, let’s skip the semantics and spare ourselves some pedantics. Let us assume that all gears have a constant velocity when you’ve averaged it all out. Sure there is a perceptible difference between a perfect involute and a primitive lantern gear, but for the sake of discussion it doesn’t matter at all. Especially if you’re just going to 3D print the thing. Let’s say that they’re sitting on perfect bearings and friction isn’t a thing unless we make it so. Also we’ll go ahead and make them perfectly aligned, depthed, and toleranced.

Typically, a gearbox is used for two things. You have a smaller torque that you’d like to make into a bigger one or you have one rotational velocity that you’d like to exchange for another.  Typically torque is represented with a capital or lowercase Tau (Ττ) and rotational velocity likes to have a lowercase omega (ω). It also doesn’t matter at all; it just makes your equations look cooler.

Now a lot of tutorials like to start with the idea of rolling a smaller circle against a bigger one. If the smaller circle is a third as large as the big one, it will take three rotations of the small circle to make the big one rotate twice.  However, it is my opinion that thinking it in terms of the force applied allows a designer to think about the gearing more effectively.

If the friction between the two surfaces of the circle is perfect, then any force applied tangentially to one of the circles will result in a perfectly perpendicular and equal force to the other circle at the point of contact between the two. Midway through writing the preceding sentence I began to understand why textbooks are so abstruse, so I also drew a picture. This results in two equations.

Now, when you have a force perpendicular to the line drawn to describe the radius, the equation for torque becomes really simple.

Multiply the length of the “lever arm”, “radius”, etc. by the force to get the preceding equations. Make sure to include the units.

You should end up force-unit * length-unit. Since I usually work in smaller gears I like to use N * mm. American websites typically use oz-in to rate motors. It is technically ozf-in (ounce-force), but the US customary system has a fetish for obtuseness.

We can make some observations. The smaller gear always sees less torque at its center. This initially seemed a bit counter-intuitive to me. If I’m using a cheater bar to turn a bolt the longer I make the bar the more torque I can put on the bolt. So if I touch the outside of a really large gear I should be seeing a ton of torque at the center of a small gear rotating along with it. However, as we mentioned before, any torque applied on the outside of the larger gear is seen equal and tangential on the smaller. It’s as if you’re touching the outside of the small gear. The torque has to be smaller.

This is why you have to pedal so much harder when the rear sprocket on a bicycle gets smaller.  Each time you make the sprocket smaller you shrink the torque input into the wheel. If the perpendicular output where the wheel hits the ground is <input from the small gear> / <radius of the wheel> then it’s obvious why this happens.

Hopefully my diagram doesn’t win a prize for awfulness. Then again, an award is an award. Remember that the bicycle wheel and  its input gear are rigidly attached to each other.

It’s also important to note that any time you increase the torque, the speed of the gears slow by the same proportion. If you need 60 N*m out of a motor that can give 20 N*m and you use a 3:1 gearbox to do it. If the motor previously ran at 30 rpm it’s now running at 10 rpm.

Let’s jump right into an example. Let’s say you want to make a device that automatically lifts your window blinds. You’ve got some junk and a 3D printer.

The problem set-up.

Now you’ve taken a spring scale and pulled until the shutter moves and you know you need 10 lbs. of pull to get the blinds to pull up. To make it easy on yourself you multiply this number by two so you know you need exactly 20 lbs of force to pull the curtain up. Then to make it really easy on yourself convert it all to Newtons. It’s approximately 90 N.

Now you don’t really care how fast the blinds pull up, but you go ahead and pull them up yourself. You get the feeling that the blinds won’t appreciate being lifted faster than the whole range in two seconds. You personally don’t care if takes ten seconds to, but you’d like it not to take too long.

You also measure the length of string pulled out to raise the blinds. It’s 1.2 meters.

A classic.

Lastly, you only have one spare power supply and a matching motor left in your entire laboratory after you followed the advice in a Hackaday article. Cursing the day the author was born, you sullenly write down the last specifications. You’ve got one of those cheap GM9 gear motors. 5 V, 66 rpm, and 300 N*mm. You damn him as you think fondly of your mountain of windshield washer motors and 80 lb server rack power supplies that you tossed out.

To start with, you do some experiments with a pulley. You arbitrarily pick, 3D print, and find that a 100 mm in diameter pulley seems to wind it up nicely by hand. By the end of the winding the outside diameter of the string is 110 mm. So you use the torque equations above. You find that at the end of the rotation, if you attach the motor directly, there is only 5.45 N of force being applied to the string. Not nearly enough.

Hrm..

So, since you know everything is more or less proportional, you divide 90 N / 5.45 N, and arrive at an answer of 17. So, at a minimum for every turn of the pulley you need 17 turns of the motor to get the torque needed.

That would be okay, but it messes with our other specification. At a 17:1 ratio, it will take our 66 rpm motor pretty close to a minute to wind the blinds up.

Damn.

This is a moment for some pondering. Make a coffee. Maybe go write a relaxing comment to a Hackaday writer listing their various flaws, perceived and true, in excruciating detail.

What if you wound the string up on a closet rod? Those are only about 30 mm in diameter. You take a bit of rod and wind it up. It seems to work and since it’s wider the string only ends up adding 5 mm to the final diameter. You rework the calculation and find that in this case you only need a ratio of 6! Yes.

Now some of you who have done this before are likely gnashing your teeth, or more likely already down in the comments. Unfortunately it’s all proportional. While you only need a ratio of 6:1 now, nearly a third. You also need to rotate the pulley approximately three times as much to pull the same length of cord.

Sometimes you can’t win. In this case the only solution is to order a new motor. You look online for a bit and realize that one of the 12 V motors you threw away last week would work perfectly for this. You wouldn’t even need a gear box. You could attach it straight to the pulley. You look around your perfectly clean and orderly garage and feel empty.

However, just for fun you build a 6:1 gearbox anyway. It’s a hack after all.

Cover photo of the hilariously complicated Do Nothing Machine credit to the Joe Martin Foundation.


Filed under: Curated, Engineering, Hackaday Columns, how-to

Real-Life Space Invaders with Drones and Lasers

จันทร์, 09/19/2016 - 22:31

We’ve seen a proliferation of real-life video game builds lately, but this one is a jaw-dropper! [Tomer Daniel] and his crew of twelve hackers, welders, and coders built a Space Invaders game for GeekCon 2016.

[Tomer] et al spent more time on the project than the writeup, so you’re going to have to content yourselves with the video, embedded below, and a raft of photos that they sent us.

[Tomer]’s company makes software for coordinating UAV fleets, so it’s not a coincidence that he would have eight DJI Phantom’s onhand and the ability drive them. The team put together RGB LED matrices, laser sensors, and outfitted each Invader with its own Arduino.

The welders built up a track and cart so that the player would slide back and forth over a twenty meter set of rails. The video shows off the gun in action. (The barrel effect is reminiscent of this hack by Seb Lee-Delisle] that we just covered.) Of course, the turret doesn’t let you just spam the laser, but turns it off after a short delay to force you to actually take aim.

After a hit is registered, the quadcopter turns its lights off and returns to the ground. How cool is that? Enjoy the video.

Now that you’re done reading this blogpost, go check out the rest of the projects at GeekCon. Some of them are nearly equally amazing.


Filed under: drone hacks

Preparing Your Product For The FCC

จันทร์, 09/19/2016 - 21:01

At some point you’ve decided that you’re going to sell your wireless product (or any product with a clock that operates above 8kHz) in the United States. Good luck! You’re going to have to go through the FCC to get listed on the FCC OET EAS (Office of Engineering and Technology, Equipment Authorization System). Well… maybe.

As with everything FCC related, it’s very complicated, there are TLAs and confusing terms everywhere, and it will take you a lot longer than you’d like to figure out what it means for you. Whether you suffer through this, breeze by without a hitch, or never plan to subject yourself to this process, the FCC dance is an entertaining story so let’s dive in!

Did You Mean to Transmit that Signal?

There are two kinds of things that are getting tested; intentional radiators and unintentional radiators. Intentional means they are purposely putting out RF signals, like WiFi, Bluetooth, or any other transmitting radio. These must be tested and filed with the FCC before you can start selling or even marketing your product. Here you are looking at CFR 47 Part 15, Section 247 most likely.

Then there are unintentional radiators. This could be switching noise from a power supply, accidental antennas from poor ground pours, or long clock traces. You need to have your product tested for unintentional radiation (if you are an intentional transmitter you still have to have unintentional radiation testing as well), but you don’t necessarily need to have the reports sent to the FCC. Depending on the type of product, you will either need to do Verification (you don’t need an official testing lab and you keep the reports yourself in case you get asked), Declaration of Conformity (you need an official testing lab, but you keep the reports yourself in case you get asked), and Certification (in which you use an accredited testing lab and the FCC reviews the filed documents).  The relevant part of the FCC guidelines is CFR 47, Part 15, Section 109.

There’s another thing to consider, and that’s FCC Modular Approval. If you want to avoid all the hassle and expense of intentional emission testing, you can use a wireless module that has modular approval. There are lots of companies that make these modules for BLE, WiFi, Zigbee, GSM, and pretty much any wireless tech. They go through the painful FCC process for you and sell you their module, which has the chip, balun, antenna, crystal, and shield, all in a pretty package that you can solder onto your PCB. This will avoid the intentional emissions testing and give you an optimized transmitter. You’re still responsible for unintentional radiation on your full board, but this is much cheaper and easier and may not even need to be filed.

For low volumes of products, modules are a great way to jumpstart product development and start scaling up, and when you have proven the market and the economics make sense to switch (usually in the tens of thousands in volume), then you can go to your own design.

Get Into a Test Facility

Let’s pretend you’re selling a WiFi toothbrush that records how long you’ve been brushing and uploads it to the cloud so that parents can hover over their children in yet another way. You’ll have to get your product tested for both Sections 109 and 247. The FCC doesn’t have their own testing facilities to do this; they accredit other testing facilities, and they’re located around the world. They even have a tool to help you find them.

Request quotes from a few test facilities as well as timelines for when they can get your product into their facility for testing. They will generally handle the filing after you fill out a few forms. Quotes for an intentional transmitter may contain sections for the following (rough ballpark numbers. your results may vary):

  • CFR 47 Part 15 Section 247 – testing for intentional radiated emissions ~$5k
  • CFR 47 Part 15 Section 109 – testing for unintentional radiated emissions ~$1k
  • Test report documents ~$1k
  • FCC Form 731 and some other filing paperwork ~$2k
  • IC paperwork – $2k

What’s the IC? That’s Industry Canada, and if you want to sell in Canada, you have to jump through a couple extra hoops, but it’s better to do it at the same time than later and have to rerun the tests. Your test facility will help you navigate all the accounts you need to create and documents to file.

Do Your Homework

Once you’ve picked your facility, you need to prepare your Equipment Under Test (EUTs) and LOTS of documentation. The documentation can take a month or more to prepare and get settled. They want to know everything, including what the label is going to look like and how it will be affixed to the product permanently.

This prep work doesn’t end with the photos, user manual, Description of Operation, schematics, and block diagrams (the documents you see on the FCC EAS web site are a subset of the total number of documents prepared). You also have to prepare a test procedure document and make sure that your firmware is ready to handle all the strange modes you will have to put it in, and the other hardware you send (like any computers you install software on to control or reprogram the EUTs) is ready and easy to use. Time in the chamber is extremely expensive, and you want your testers to have as easy a time as possible and not need to contact you with a simple problem caused by an oversight.

A Test of Every Flavor

With the EUTs, they’re going to want to test in all possible configurations, so you’ll need to test your WiFi toothbrush when it’s running on battery, but also when it’s plugged in to the wall to charge. If you are including a charger, you’ll have to include the charger in the tests, even if it says it’s already FCC certified, because it’s the combination that you are selling which must meet the standards.

You’ll test it in normal operating mode, but also in continuously transmitting mode on every channel possible, so you’ll need to include firmware (or some way to control) which channel it is on and to put it in a special mode that allows for continuous transmission. Sometimes, manufacturers have made this a bit easier for you. For instance, if you are using a TI chip there is SmartRF Studio, which makes this really easy.

Fixing Your Oversteps

The FCC guidelines allow for certain powers at specific frequency ranges, so it’s possible that your device might be ever so slightly outside the range at the highest or lowest channel. You’ll either have to change the PCB, or you may be able to get away with writing firmware that limits the power at those extremes (you’ll have to have this tested), or write firmware that prevents the device from using those channels.

The testing facility will also want to measure output power directly, which means hooking up an SMA connector to the antenna. Lots of times your product won’t HAVE an SMA connector and will just pipe straight to a trace or chip antenna. This is where you get creative and cut the trace and airwire a short wire to an SMA connector that’s firmly glued to the PCB. It’s a hack, but it’s as close as you can get to being a good measure of the output power.

The trace antenna is cut and an SMA connector is added for emissions testing.

It’s not uncommon for a design to fail the first time. This sucks, but it’s not the end of the world. The testing facility may suspend tests, tell you what they think might be wrong, and let you fix it before continuing. You’ll often see space for extra passive components in the path between the transmitter and the antenna. These are for making whatever fine adjustments are necessary to get the PCB to be in compliance.

Practice Your Patience

A note from personal experience; stay engaged with your testing facility. I was unfortunate in that mine needed constant prodding, for a few months it wasn’t responding to email or phone calls, and from signing the contract to filing with the FCC was a whopping ten months. Usually you can expect it to take one or two, but as a little guy you may have to fight a little harder.

FCC testing can be intimidating, especially if it’s your first time. Testing facilities are accustomed to FCC virgins and will do some hand-holding, but a lot of the preparations are time consuming and need to be done by you. However, this certification is crucial in unlocking a huge market for your product. As with choosing the right components, case design, manufacturing process, and packagaing, FCC testing needs to be considered when planning product development timelines and throughout the design process.

[FCC testing image source: Some Hardware Guy]


Filed under: Engineering, Featured, radio hacks

New Part Day: A Truly Secure Workstation

จันทร์, 09/19/2016 - 18:00

There is a chain of trust in every modern computing device that starts with the code you write yourself, and extends backwards through whatever frameworks you’re using, whatever OS you’re using, whatever drivers you’re using, and ultimately whatever BIOS, UEFI, Secure Boot, or firmware you’re running. With an Intel processor, this chain of trust extends to the Intel Management Engine, a system running independent of the CPU that has access to the network, USB ports, and everything else in the computer.

Needless to say, this chain of trust is untenable. Any attempt to audit every line of code running in a computer will only be met with frustration. There is no modern Intel-based computer that is completely open source, and no computer that can be verified as secure. AMD is just as bad, and recent attempts to create an open computing platform have met with frustration. [Bunnie]’s Novena laptop gets close, but like any engineering task, designing the Novena was an exercise in compromise. You can get around modern BIOSes, coreboot still uses binary blobs, and Libreboot will not be discussed on Hackaday for the time being. There is no modern, completely open, completely secure computing platform. They’re all untrustworthy.

The Talos Secure Workstation, from Raptor Engineering, an an upcoming  Crowd Supply campaign is the answer to the untrustworthiness of modern computing. The Talos is an effort to create the world’s first libre workstation. It’s an ATX-compatible motherboard that is fully auditable, from schematics to firmware, without any binary blobs.

RISC architecture is going to change everything.

‘Secure’ isn’t a word you would use in conjunction with a modern Intel processor, and AMD is just as bad. Most ARM processors are out, because there are binary blobs floating around even when the processor isn’t tied up in NDAs. Even graphics are hard to make secure, and while open source GPUs exist, they’re not exactly powerhouses.

To make a computer fully secure, you’ll have to go outside the usual architectures, and the market for a secure computer simply isn’t there to warrant a completely new architecture, anyway. For the Talos, Raptor Engineering chose IBM’s POWER8 processor. This architecture is now most common in computing that has a few more zeros on the price tag than what Microcenter offers, but historically the POWER line can be traced back through the CELL processor, the GameCube, and [Zero Cool]’s sweet clear laptop.

The rest of the hardware includes 8 DDR3 slots supporting 256GB of RAM, 2 x16 PCIe slots, 4 x8 PCIe slots, one legacy PCI slot, an internal mPCIe slot, 8 internal SATA 6Gb ports, 2 external eSATA 6Gb ports, 1 HDMI port, 8 USB 3.0 ports, 2 external and 2 internal RS232 ports, and an internal GPIO header. The full list of specifications and supported operating systems is available on the Raptor Engineering website.

It should be noted this is not the only POWER8 motherboard available. Tyan produces a POWER8 server motherboard, although it is not as open as the Talos. Even with the Talos, there are some restrictions on how open and secure it actually is; thanks to NDAs, some of the PCIe subsystem is not auditable.

Although the Crowd Supply campaign is not live yet, we know the cost of an entry-level Talos system with an 8-core 130W TDP POWER8 CPU will come in at about $5,300. A standalone board less CPU will be available for about $4,000, according to Raptor Engineering. That’s pricey, but not terrible when it comes to high performance enterprise workstations. You’re paying for security and auditability here, and we hope Talos is a success, if only to prove there is a market for truly secure computing.


Filed under: Hackaday Columns

Real, Life-Sized Transformers

จันทร์, 09/19/2016 - 15:00

Ever dreamed of a real, life-sized Transformer in your garage? The Turkish startup Letrons now offers you exactly that: Their animatronic Autobot drives like a car, transforms like a Transformer, and supposedly fights off space threats with its built-in smoke machine and sound effects.

Letrons’s Transformer seems to be built upon a BMW E92 coupé chassis. According to the company, the beast is packed with powerful hydraulics and servo motors, allowing it to transform and move fast. Sensors all around the chassis give it some interactivity and prevent it from crushing innocent bystanders when in remote-control mode. Interestingly, its movable arms aren’t attached to the body, but to its extendable side-wings and feature hands with actuated wrists and fingers. The Autobot also can move its head, which pops right out of the hood.

Admittedly, Letrons must have spent a lot of time on the dark side of the moon and working in secrecy before they released footage of a working and polished prototype. It’s unclear if Letron’s Transformers will cooperate with the US military in solving armed conflicts, but they are certainly good for a show. Enjoy the video below!

Thanks to [Itay] for the tip!


Filed under: robots hacks, transportation hacks