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A Mess Of Wires Turned Into An Analog Synth

Hackaday - 2 hours 17 minก่อน

Over on YouTube, [GumpherDM3] built one of the greatest musical projects we’ve seen in a long time. It’s an analog synthesizer that is one of a kind. It’s going to stay one of a kind, too: no one would ever want to copy this mess of wires and perfboard that was successfully turned into a complete musical instrument.

The design of this synth is what you would expect from something that draws its inspiration from semimodular synths such as the Minimoog and Korg MS20. There are four VCOs on this synth, two audio and two used for the LFOs. A four-pole low pass filter, VCA, and two envelope generators round out the purely analog portion of the build. There’s an arpeggiator in there too, which makes for a really great demo video (below).

Inside, this is a true analog synth with the VCOs, filter, and VCA built around the LM13700 transconductance amplifier. The build log shows these chips spread out around half a dozen breadboards before being plugged into sockets soldered to handwired perf board. This synth is a one of a kind instrument – no one would want to build this thing twice.

Additional features include an Arduino with a MIDI in port sending out CV signals to the analog part of the synth. This thing has everything you would expect from a modern take on an analog synthesizer, and it sounds good, too.


Filed under: musical hacks

Google WiFi issues show the downside of always-up-to-date routers

Liliputing - 4 hours 47 minก่อน

Google started getting into the consumer WiFi router space in 2015 by partnering with Asus and TP-Link to launch a line of OnHub routers. More recently Google launched its own whole-home solution called Google WiFi. Among other things, these routers are interesting because they’re supposed to be easy to set up and they download software and […]

Google WiFi issues show the downside of always-up-to-date routers is a post from: Liliputing

iPhone Brain Surgery

Hackaday - 5 hours 17 minก่อน

You think you’re good at soldering? Can you solder a CPU? A CPU inside an iPhone? A decapped CPU inside an iPhone? Can you solder inside a decapped CPU inside of an iPhone?

If you can’t, fear not – someone can, and we found him or her courtesy of a video that [Bunnie Huang] tweeted a while back. There’s not much information in the video, but from what we can gather it comes from an outfit called G-Lon Technology in Guang Zhou. Their Facebook page suggests that they teach cellphone repair, and if they take their repairs this far, we’d say the students are getting their tuition’s worth.

The reason for the repair is unclear, although the titles refer to a “CPU to U0301 AP31 AR31 broken repair,” which we take to refer to a boot error that can be repaired by exposing a couple of pads inside the CPU and wiring them to another chip. We’d love to hear comments from anyone familiar with the repair, but even in the absence of a clear reason for undertaking this, the video is pretty impressive. The epoxy cap of the CPU is painstakingly ground away under a microscope, then tiny tools are used to scrape down to the correct layers. Solder mask is applied, hair-thin wires are tacked to the pads, and a UV-curing resin is applied to fill the CPU’s new gaping hole and to stabilize the wires. It seems like a lot of work to save an iPhone, but it sure is entertaining to watch.

Can’t get enough of poking around the innards of chips? We’ve got decapping stories aplenty: one, two, and three that you might like. We’ve even covered at least one CPU internal repair before too.

Thanks to [Dr.Tune] for the tip.


Filed under: Cellphone Hacks, iphone hacks

Archos is bringing a rugged tablet, 2 dual-camera phones to MWC

Liliputing - 6 hours 17 minก่อน

Archos may have been one of the first companies to launch an Android tablet, but it’s been a while since the French company has offered anything more interesting than a line of budget phones and tablets that do little to stand out in a crowded marketplace. But this week the company did make a few […]

Archos is bringing a rugged tablet, 2 dual-camera phones to MWC is a post from: Liliputing

60 Watt USB Soldering Iron Does it with Type-C

Hackaday - 6 hours 46 minก่อน

Some time back we ran a post on those cheap USB soldering irons which appeared to be surprisingly capable considering they were really under powered, literally. But USB Type-C is slated to change that. Although it has been around for a while, we are only now beginning to see USB-C capable devices and chargers gain traction. USB-C chargers featuring the USB-PD option (for power delivery) can act as high power sources allowing fast charging of laptops, phones and other devices capable of negotiating the higher currents and voltages it is capable of sourcing. [Julien Goodwin] shows us how he built a USB-C powered soldering iron that doesn’t suck.

He is able to drive a regular Hakko iron at 20 V and 3 Amps, providing it with 60 W of input power from a USB-C charger. The Hakko is rated for 24 V operating voltage, so it is running about 16% lower power. But even so, 60 W is plenty for most cases. The USB-C specification allows up to 5 A of current output in special cases, so there’s almost 100 W available when using this capability.

It all started while he was trying to consolidate his power brick collection for his various computers in order to reduce the many types and configurations of plugs. Looking around, he stumbled on the USB-PD protocol. After doing his homework, he decided to build a USB Type-C charger board with the PD feature based on the TI TPS65986 chip – a very capable USB Type-C and USB PD Controller and Power Switch. The TI chip is a BGA package, so he had to outsource board assembly, and with day job work constantly getting in the way, it took a fair bit of time before he could finally test it. Luckily, none of the magic smoke escaped from the board and it worked flawlessly the first time around. Here is his deck of slides about USB-C & USB-PD [PDF] that he presented at linux.conf.au 2017 Open Hardware Miniconf early this year. It provides a nice insight to this standard, including a look at the schematic for his driver board.

Being such a versatile system, we are likely to see USB-C being used in more devices in the future. Which means we ought to see high power USB Soldering Irons appearing soon. But at the moment, there is a bit of a “power” struggle between USB-C and Qualcomm’s competing “Quick Charge” (QC) technology. It’s a bit like VHS and Betamax, and this time we are hoping the better technology wins.


Filed under: peripherals hacks, tool hacks

Deals of the Day (2-24-2017)

Liliputing - 7 hours 47 minก่อน

Mesh networking is the latest trend in home WiFi routers. If a single router fails to blanket your house with wireless internet access, then you might want to consider picking up a system that lets you place two or three stations around your home to cover hard-to-reach places. One of the first big players in the […]

Deals of the Day (2-24-2017) is a post from: Liliputing

About Schmitt (Triggers)

Hackaday - 8 hours 16 minก่อน

There is an old saying: “In theory, theory and practice are the same. In practice, they are not.” We spend our time drawing on paper or a computer screen, perfect wires, ideal resistors, and flawless waveforms. Alas, the real world is not so kind. Components have all kinds of nasty parasitic effects and no signal looks like it does in the pages of a text book.

Consider the following problem. You have a sine wave input coming in that varies between 0 V and 5 V. You want to convert it to a square wave that is high when the sine wave is over 2.5 V. Simple, right? You could use a CMOS logic gate or a comparator. In theory…

The problem is, the sine wave isn’t perfect. And the other components will have little issues. If you’ve ever tried this in real life, you’ll find that when the sine wave is right at the 2.5 V mark the output will probably swing back and forth before it settles down. This is exacerbated by any noise or stretching in the sine wave. You will wind up with something like this:

Notice how the edges of the square wave are a bit fat? That’s the output switching rapidly back and forth right at the comparator’s threshold.

Hysteresis

The answer is to not set the threshold at 2.5 V, or any other single value. Instead, impose a range outside of which it will switch, switching low when it leaves the low end of the range, and high when it exceeds the high end.  That is, you want to introduce hysteresis. For example, if the 0 to 1 shift occurs at, say, 1.9 V and the 1 to 0 switch is at 0.5 V, you’ll get a clean signal because once a 0 to 1 transition happens at 1.9 V, it’ll take a lot of noise to flip it all the way back below 0.5 V.

You see the same effect in temperature controllers, for example. If you have a heater and a thermal probe, you can’t easily set a 100 degree set point by turning the heater off right away when you reach 100 and then back on again at 99.9999. You will usually use hysteresis in this case, too (if not something more sophisticated like a PID). You might turn the heater off at 99 degrees and back on again at 95 degrees, for example. Indeed, your thermostat at home is a prime example of a system with hysteresis — it has a dead-band of a few degrees so that it’s not constantly turning itself on and off.

Schmitt Triggers and How to Get One

A Schmitt Trigger is basically a comparator with hysteresis. Instead of comparing the incoming voltage with VCC / 2, as a simple comparator would, it incorporates a dead band to ensure that logic-level transitions occur only once even in the presence of a noisy input signal.

Schmitt Trigger Symbol by Selket CC-BY 2.5

Assuming you want a Schmitt trigger in a circuit, you have plenty of options. There are ICs like the 74HC14 that include six (inverting) Schmitt triggers. On a schematic, each gate is represented by one of the symbols to the right; the little mark in the box is the hysteresis curve, and the little bubble on the output indicates logical negation when it’s an inverter.

You can also make them yourself out of transistors or even a 555 chip. But the easiest way by far is to introduce some feedback into a plain op amp comparator circuit.

Below are two op amps, one with some positive feedback to make it act like a Schmitt trigger. The other is just a plain comparator. You can simulate the design online.

 

If you haven’t analyzed many op amp circuits, this is a good one to try. First, imagine an op amp has the following characteristics:

  • The inputs are totally open.
  • The output will do whatever it takes to make the inputs voltages the same, up to the power supply rails.

Neither of these are totally true (theory vs. practice, again), but they are close enough.

The comparator on the right doesn’t load the inputs at all, because the input pins are open circuit, and the output swings to either 0 V or 5 V to try, unsuccessfully, to make the inputs match. It can’t change the inputs because there is no feedback, but it does make a fine comparator. The voltage divider on the + pin provides a reference voltage. Anything under that voltage will swing the output one way. Over the voltage will swing it the other way. If the voltages are exactly the same? That’s one reason you need hysteresis.

The comparator’s voltage divider sets the + pin to 1/2 the supply voltage (2.5 V). Look at the Schmitt trigger (on top). If the output goes between 0 V and 5 V, then the voltage divider winds up with either the top or bottom resistor in parallel with the 10K feedback resistor. That is, the feedback resistor will either be connected to 5 V or ground.

Of course, two 10K resistors in parallel will effectively be 5K. So the voltage divider will be either 5000/15000 (1/3) or 10000/15000 (2/3) depending on the state of the output. Given the 5 V input to the divider, the threshold will be 5/3 V (1.67 V) or 10/3 V (3.33 V). You can, of course, alter the thresholds by changing the resistor values appropriately.

Practical Applications

Schmitt triggers are used in many applications where a noisy signal requires squaring up. Noisy sensors, like an IR sensor for example, can benefit from a Schmitt trigger. In addition, the defined output for all voltage ranges makes it handy when you are trying to “read” a capacitor being charged and discharged. You can use that principle to make a Schmitt trigger into an oscillator or use it to debounce switches.

If you want to see a practical project that uses a 555-based Schmitt, check out this light sensor. The Schmitt trigger is just one tool used to fight the imprecision of the real world and real components. Indeed, they’re nearly essential any time you want to directly convert an analog signal into a one-bit, on-off digital representation.


Filed under: Engineering, Hackaday Columns

Bluetooth 5.0 devices are on the way

Liliputing - 8 hours 34 minก่อน

Bluetooth a standard for short-range wireless communications between electronic devices… but the short range part of that may be a bit dated. The Bluetooth 5.0 standard was announced in December, and it offers up to 4 times the range and up to twice the speed. Now it looks like some of the first devices with Bluetooth […]

Bluetooth 5.0 devices are on the way is a post from: Liliputing

Join Hackaday And Tindie At The Southern California Linux Expo

Hackaday - 9 hours 2 minก่อน

Do you like Open Source? Join Hackaday and Tindie at the largest community-run Open Source conference in North America. We’ll be at the Southern California Linux Expo next week, and we want to see you there.

What’s happening at SCALE this year? Amateur radio license exams, a PGP signing party, Bad Voltage Live and The Spazmatics, and a ton of great talks.

Hackaday and Tindie will be at SCALE Friday through Sunday, showing off the coolest parts of Hackaday, Hackaday.io, and our lovable robotic dog, Tindie. We’ll be handing out t-shirts and stickers, and we’ll be giving tours of the SupplyFrame Design Lab located just two blocks away from the convention center. The Design Lab is a crown jewel of our corporate overlord’s emphasis on Open Hardware, and if you want to see where the magic happens, this is your chance. We’ll be running tours of the Lab on Friday, so find the Hackaday and Tindie crew in the expo area around 3:40 PM.

Here’s something cool: We’re offering discounted SCALE passes, too. They’re 50% off using the code ‘HACK’ at this link. That’s $45 for four days of fun.

SCALE is much more interesting than I’m letting on here. Last year, I was absolutely befuddled by the Microsoft booth, and their stickers saying that ‘Microsoft (heart) Linux’. A few weeks later, and a day short of the best April Fool’s joke of all time, Microsoft said Cygwin Can Suck It. Somehow or another, the Linux Subsystem for Windows 10 made it to SCALE and nobody noticed. Let’s see what we find this year.


Filed under: cons, Hackaday Columns

LG Gram 2017 ultralight notebooks go on sale for $1000 and up

Liliputing - ศุกร์, 02/24/2017 - 23:45

The latest LG Gram laptops are now available for purchase in the US, with prices starting at $1,000 for an entry-level model. LG’s Gram line of computers get their name from their extraordinarily light weight: historically the laptops have weighed about one kilogram, or roughly 2.2 pounds. The new 2017 models LG unveiled at CES […]

LG Gram 2017 ultralight notebooks go on sale for $1000 and up is a post from: Liliputing

United Nations defines 5G: At least 20 Gbps max downloads (and 100 Mbps average)

Liliputing - ศุกร์, 02/24/2017 - 23:14

You’re going to hear a lot about so-called “5G” technology in the next year or two, as wireless carriers, phone makers, and mobile chip designers start rolling out new products designed to offer faster, more reliable mobile data connections than 4G LTE. But what exactly is 5G? According to new guidelines from the United Nations’ International […]

United Nations defines 5G: At least 20 Gbps max downloads (and 100 Mbps average) is a post from: Liliputing

Cloudbleed — Your Credentials Cached in Search Engines

Hackaday - ศุกร์, 02/24/2017 - 23:00

In case you are still wondering about the SHA-1 being broken and if someone is going to be spending hundreds of thousands of dollars to create a fake Certificate Authority and sniff your OkCupid credentials, don’t worry. Why spend so much money when your credentials are being cached by search engines?… Wait, what?

A serious combination of bugs, dubbed Cloudbleed by [Tavis Ormandy], lead to uninitialized memory being present in the response generated by the reverse proxies and leaked to the requester. Since these reverse proxies are shared between Cloudflare clients, this makes the problem even worst, since random data from random clients was leaking. It’s sort of like Heartbleed for HTTP requests. The seriousness of the issue can be fully appreciated in [Tavis] words:

“The examples we’re finding are so bad, I cancelled some weekend plans to go into the office on Sunday to help build some tools to cleanup. I’ve informed cloudflare what I’m working on. I’m finding private messages from major dating sites, full messages from a well-known chat service, online password manager data, frames from adult video sites, hotel bookings. We’re talking full https requests, client IP addresses, full responses, cookies, passwords, keys, data, everything.”

According to Cloudflare, the leakage can include HTTP headers, chunks of POST data (perhaps containing passwords), JSON for API calls, URI parameters, cookies and other sensitive information used for authentication (such as API keys and OAuth tokens). An HTTP request to a Cloudflare web site that was vulnerable could reveal information from other unrelated Cloudflare sites.

Adding to this problem, search engines and any other bot that roams free on the Internet, could have randomly downloaded this data. Cloudflare released a detailed incident report explaining all the technicalities of what happened and how they fixed it. It was a very quick incident response with initial mitigation in under 47 minutes. The deployment of the fix was also quite fast. Still, while reading the report, a sense that Cloudflare downplayed this issue remains. According to Cloudflare, the earliest date that this problem could have started is 2016-09-22 and the leak went on until 2017-02-18, five months, give or take.

Just to reassure the readers and not be alarmist, there is no evidence of anyone having exploiting what happened. Before public exposure, Cloudflare worked in proximity with search engines companies to ensure memory was scrubbed from search engine caches from a list of 161 domains they had identified. They also report that Cloudflare has searched the web (!), in sites like Pastebin, for signs of leaks and found none.

On the other hand, it might be very well impossible to know for sure if anyone has a chunk of this data cached away somewhere in the aether. It’s impossible to know. What we would really like to know is: does [Tavis] get the t-shirt or not?


Filed under: news, security hacks

What Does a Hacker Do With A Photocopier?

Hackaday - ศุกร์, 02/24/2017 - 22:01

The year is 2016. Driving home from a day’s work in the engineering office, I am greeted with a sight familiar to any suburban dwelling Australian — hard rubbish. It’s a time when local councils arrange a pickup service for anything large you don’t want anymore — think sofas, old computers, televisions, and the like. It’s a great way to make any residential area temporarily look like a garbage dump, but there are often diamonds in the rough. That day, I found mine: the Ricoh Aficio 2027 photocopier.

It had spent its days in a local primary school, and had survived fairly well. It looked largely intact with no obvious major damage, and still had its plug attached. Now I needed to get it home. This is where the problems began.

The 1991 Daihatsu Feroza is not, as it turns out, an appropriate transport for this task. A combination of its high rear floor and small cargo area (even with the rear seats removed) made loading the copier physically impossible. I will not overstate the weight of this copier, approximately speaking, it was Damn Heavy™. Calls to the few friends I’d made in my short time in Victoria came to nothing, so an alternative solution had to be found.

The south-eastern suburbs of Melbourne are remarkably hilly. It had become my task to push a 62 kg office multifunction 1.4 kilometers home (137 pounds and just less than a mile). Considering this was a piece of hardware I’d found on the side of the road, over the next forty minutes I began to realise I almost literally became the modern Sisyphus.

Quite the struggle. Is This Thing On?

Upon getting it home, I plugged it in.

I was greeted with the phrase “Please wait…” for about ten minutes. I remained hopeful, and then… beeps! The error code SC990 was given, as well as a local number to call for service — though that seemed like giving up, and they’d ask a few too many questions on turning up to a residential address. I persevered, and found that if I quickly cycled the power, the copier would successfully boot.

Now I was really excited. This was the best part of my plan. With the copier sitting by the fridge, I left it powered on and took a photo. I quickly sent it to my housemates in a group chat.

“Guys, I’m really tired of this. If you’re leaving the house would you PLEASE remember to turn the photocopier off before you go? Come on.”

Their confusion and laughter was totally worth it. At this point, though, I reached an impasse — what does one actually do with a free photocopier? Wait, of course! I promptly removed my pants.

The Stuff You Can’t Do With the Work Copier

It took me a little while to master the proper technique. It’s not enough to simply sit down, placing one’s entire weight on the photocopier to image the buttocks. Even ignoring the risk of being crushed in the event of the copier falling over, the imaging bed isn’t designed as a seat. The plastic frame tends to deform under this sort of load, just enough to stop the scanning bar moving across the platen. Instead, it’s necessary to support oneself by placing the hands on the corners of the copier, hovering above the platen, ideally with an assistant to help you by pressing the start button.

In all seriousness, though, short of reinforcing the copier bed with a steel frame to enable the easier imaging of the human anatomy, I was running short on ideas and paper was jamming repeatedly. This test run behind me, I had an agonizing troubleshooting session ahead. Luckily, there were still a few beers in the fridge.

Amateur Copier Repair A jammed print. Notice the rippling from the paper bunching up in the various rollers.

I had to figure out why the paper was getting jammed — for your viewing enjoyment, I filmed the process and embedded it below. The great thing is, over the last 20 years, copiers have started to include big, obvious pictorial instructions on both the LCD and the frame that help you troubleshoot a jam. Enabling users to sort out the easy issues has probably saved millions, if not billions, in service calls.

I did some research online, and came across talk of a paper feed clutch. After turning up the service manual for my copier, I found out how to enter not just Service Mode, but Special Service Mode! This allowed fine control of the photocopier’s deepest, darkest settings. I changed the clutch settings to 10mm, up from 6mm and tried to make 5 copies in succession. No dice — things jammed up again. It didn’t really feel like what I was doing had any effect.

A shot of paper jammed in the teeth that are meant to guide the print away from the fuser, towards the output rollers.

I sat down and had a think. Upon close examination of where the paper was jamming, it looked like instead of rolling over the fuser (the hot roller that bonds the toner to the paper) and peeling away, it seemed like the paper was sticking to the fuser too long and winding up jammed under the teeth designed to guide it off the fuser. Back to the service manual!

I decided to try cooling down the fuser. That would perhaps stop the paper sticking so much and then it would freely pass through to the output rollers. I dialled things down from 170 to 140 degrees. After checking the temperature monitor and confirming the roller temperature was following the settings changes, I successfully made 10 copies in a row with no jams. Success? Perhaps! But if there’s one thing I learned in my career as a manufacturing engineer, it’s not enough to change a setting and call it fixed. You’ve got to confirm your hypothesis is correct.

I decided to go the other way — I cranked the fuser temperature up to 185 C, hit Start, and waited with bated breath. Not entirely to my surprise, I got ten copies out, no problem. A second trial confirmed things were humming along smoothly. On the one hand, my copier worked — great! On the other, it kind of meant I had no idea what was going on.

Compare the prints from the hotter and colder fuser settings – note the spotting on the colder print.

I compared the 185 degree copies with the 140 degree copies, as seen in the image below. Oddly enough, there was some random spotting on the colder copies that wasn’t present on the hotter ones. For all I know, however, this might have just been old toner that was stuck to the rollers that came off at the higher temperature. In the end though, it seems to be printing well now at 185 degrees, only jamming occasionally. In the rare event it does, opening all the access panels, removing the jam, and closing them again is generally enough to get things ticking over smoothly again.

Did I solve the jamming issue? I guess I did. Do I know how? Not really. But if and when it comes back, I’ll be armed with more knowledge to attack the problem once more. If you’re a photocopier tech, please watch the video and tell me what I’m missing. I’d love to get an expert opinion on how to sort this out.

What Now?

The troubleshooting process was a lot of fun. But now I’m back to figuring out what to do with the copier. I’ve currently got the copier wired up to my home network as a printer and scanner, and could hook it up to my vintage computers over parallel or even AppleTalk if I so desired. But all of these ideas are simply using the copier for its intended purpose. Thus far, all I’ve really done is given it a name; it shall henceforth be known as Printmaster Flush.

I ask you — what does a hacker do with a free photocopier? I’m not content to just use this gift as it was intended. I’d like to build something truly unique and awesome with it, I just don’t know what. Please, share with me your ideas in the comments and any stories you have yourself of office hardware hijinx. Check out the video below for a play-by-play on dragging it home and dealing with the jamming issues.


Filed under: Featured, peripherals hacks, repair hacks

Head of the company behind India’s $4 smartphone arrested for fraud

Liliputing - ศุกร์, 02/24/2017 - 21:53

Remember that smartphone that Indian government officials said would be made in India and sell for less than $4? The founder of the company behind that phone was arrested on fraud charges yesterday. Ringing Bells actually started shipping its Freedom 251 phone in mid-2016. But a number of distributors have alleged that they placed orders […]

Head of the company behind India’s $4 smartphone arrested for fraud is a post from: Liliputing

Toast-Bot Butters For You (Sometimes)

Hackaday - ศุกร์, 02/24/2017 - 19:01

Sometimes — despite impracticality, safety, failure, and general good sense — one has an urge to see a project through for the sake of it. When you’re sick of buttering your toast every morning, you might take a leaf out of Rick Sandc– ahem, [William Osman]’s book and build a toast-bot to take care of the task for you.

[Osman] — opting for nail the overkill quotient — is using a reciprocating saw motor to hold the butter while the toast moves underneath the apparatus on a platform controlled by a linear stepper motor. The frame and mounts for Toast-Bot were cut out of wood on his home-built laser cutter — affectionately named Retina Smelter 9000′ — and assembled after some frustration and application of zip-ties. The final result DOES butter toast, but — well — see for yourself.

Despite working with only margerine-al (sorry!) success from a practical standpoint — equally inclined to shred or butter — we are inclined to chalk this up as a win regardless. A robot doesn’t always need to be perfect to prove that it can be done — especially if it does the job in a deliberately comedic fashion.


Filed under: hardware, robots hacks

3D Printing Using Holograms is Actually Printing in 3D

Hackaday - ศุกร์, 02/24/2017 - 16:01

It’s the year 2260 and you’re being beamed from your starship to the planet below. Being a descendant of present day 3D printers, the transporter prints you out, slowly making one layer before moving on to the next, going from the ground up. The you-that-was hopes nothing spills out before you’re done. But what if you could print every atom in your body at the same time? If those transporters are descendant’s of Daqri’s holographic 3D printing technology then that’s just what will happen.

Daqri’s process is akin to SLA (stereolithography) and SLA/DLP (digital light processing). In SLA, a laser beam is shone onto a pool of resin, hardening the resin at the beam’s point. The laser scans across the resin’s surface, drawing one layer. More resin is added and then the next layer is drawn. In SLA/DLP, the light for an entire layer is projected onto the surface at once. While both methods involve stereolithography, the acronym SLA by itself is commonly used to refer to the laser approach.

Holograhically 3D printing a paperclip

Daqri’s process however, uses a holographic chip of their own making to project the light for all the layers at the same time into the material, a light-activated monomer. Their chip is a silicon wafer containing a grid of tunable crystals. Those crystals control the magnitude and phase of light reflected down into the monomer, creating a 3D volume of interference patterns. The brief description of the process says that a laser is used to shine light onto the crystals, so there’s probably still some scanning going on. However, in the video, all of the object being printed appears illuminated at the same time so the scanning is likely very fast, similar to how a laser in a light show seemingly paints what appears to be a 2D shape on the side of a building, even though it’s really just a rapidly moving point. There’s also the possibility that the beam’s point is large enough to encapsulate all of the chip at once. You can see a demonstration of it in the video below.

In the video, Daqri prints a small paperclip, and the reason for that small size is likely due to the size of their chip. But if it’s scaled up then heating may become an issue. The “hardening” that goes on, called polymerization, involves the formation of long, tangled polymers from monomers and is exothermic, meaning it gives off heat. If, like us, you’ve worked with resin before then you’ve probably noticed how hardening a large volume of resin produces more heat than hardening a small volume. That heating can be enough to melt and deform the object itself.

There’s no word on when this process will escape the lab and appear in our workshops, but for a future Star Trek transporter, it’s a step in the right direction. In the meantime, for an SLA/DLP 3D printer, have a look at the open source RooBee One.

Our thanks to Sascho for tipping us off about this.


Filed under: 3d Printer hacks

Universal Radio Hacker

Hackaday - ศุกร์, 02/24/2017 - 13:00

If you are fascinated by stories you read on sites like Hackaday in which people reverse engineer wireless protocols, you may have been tempted to hook up your RTL-SDR stick and have a go for yourself. Unfortunately then you may have encountered the rather steep learning curve that comes with these activities, and been repelled by a world with far more of the 1337 about it than you possess. You give up after an evening spent in command-line dependency hell, and move on to the next thing that catches your eye.

You could then be interested by [Jopohl]’s Universal Radio Hacker. It’s a handy piece of software for investigating unknown wireless protocols. It supports a range of software defined radios including the dirt-cheap RTL-SDR sticks, quickly demodulates any signals you identify, and provides a whole suite of tools to help you extract the data they contain. And for those of you scarred by dependency hell, installation is simple, at least for this Hackaday scribe. If you own an SDR transceiver, it can even send a reply.

To prove how straightforward the package is, we put an RTL stick into a spare USB port and ran the software. A little investigation of the menus found the spectrum analyser, with which we were able to identify the 433 MHz packets coming periodically from a wireless thermometer. Running the record function allowed us to capture several packets, after which we could use the interpretation and analysis screens to look at the binary stream for each one. All in the first ten minutes after installation, which in our view makes it an easy to use piece of software. It didn’t deliver blinding insight into the content of the packets, that still needs brain power, but at least if we were reverse engineering them we wouldn’t have wasted time fighting the software.

We’ve had so many reverse engineering wireless protocol stories over the years, to pick only a couple seems to miss the bulk of the story. However both this temperature sensor and this weather station show how fiddly it can be without a handy software package to make it easy.

Via Hacker News.


Filed under: radio hacks

Jean-Luc PYcARD is a Pocketable Python Development Platform

Hackaday - ศุกร์, 02/24/2017 - 10:00

It’s a good thing that a ridiculous pun and a screenprint of Jean-Luc Picard on the bottom of the board is enough to qualify for the 2017 Hackaday Sci-Fi Contest, because [bobricius]’s Python-plus-Arduino card and environmental sensor potpourri is very cool.

The PCB design itself is great. It’s got a gigantic LED array, cutout for a wrist strap, and an onboard USB plug so you can program it just by sticking it in your computer; it shows up as a USB mass storage device when you plug it in. The files that show up on the “drive” are Micropython code that you can edit, save, and then run directly on the device. You can hardly beat that for convenience.

And there’s a full complement of sensors: not one but two temperature and humidity sensors, including our recent favorite BME280, which also reads barometric pressure. (We suspect that makes it a tri-corder.) There’s a real-time clock, a buzzer, and some buttons. Want to add more sensors? I2C ports are broken out for your convenience.

Besides having Star Trek flair, this board would give the various educational platforms a run for their money: Micro:bit, we’re looking at you. Very cool indeed!


Filed under: Microcontrollers

LG X power2: Budget phone promises all-weekend battery life

Liliputing - ศุกร์, 02/24/2017 - 08:24

LG’s next flagship phone is coming soon, but while we wait for the official LG G6 announcement, the company has unveiled something a little different: a value-oriented phone that promises extra-long battery life. The LG X power2 is a smartphone with a 5.5 inch screen and a 4,500 mAh battery that LG says should be […]

LG X power2: Budget phone promises all-weekend battery life is a post from: Liliputing

Google’s Allo chat app is coming to desktop/web

Liliputing - ศุกร์, 02/24/2017 - 08:12

Google has a habit of launching new messaging apps. Sometimes it even keeps developing them. And it looks like the latest is coming to new places. The company launched the Allo messaging app last year, but it was only available for mobile devices running Android or iOS at the time. So while you could use […]

Google’s Allo chat app is coming to desktop/web is a post from: Liliputing

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