You want old skool electronic music? How about 1951?
Researchers at the University of Canterbury in New Zealand have just restored what is probably the oldest piece of recorded, computer-generated music. Recorded in 1951, the rendition of “God Save The King”, “Baa-Baa Black Sheep” and “In The Mood” was produced by a computer built by none other Alan Turing and other researchers at the Computing Machine Research Laboratory in Manchester.
These phat beats were captured by the BBC for broadcast on an acetate disk that the researchers found in an archive. They sampled and restored the recording, fixing the rather poor quality recording to reproduce the squawky tones that the computer played. You can hear the restored recording after the break.
It halts apparently unexpectedly in the middle of a stanza, sounds essentially horrible, and goes out of tune on the higher notes. But you gotta learn to crawl before you can walk, and these are the equivalent of the grainy 8mm films of baby’s first steps. And as such, the record is remarkable.
Via ABC News
Filed under: musical hacks, news
[Nick Poole] over at SparkFun was playing with some force resistive strips. He wanted to use them as a keyboard input. It occurred to him that the office laminator could feasibly laminate a sheet of paper and the resistor into one sealed piece.
He put the assembly inside the pouch, ran it through the laminator, and it worked! After this success he built on it to make a full resistive keyboard. Then it occurred to him to ask, as it would to any good hacker with access to expendable company property “what else can I laminate”? Basically everything.
His next experiment was an LED throwie. No problem. Bolstered by the battery not exploding, he got more creative. The next victim was one of SparkFun’s Arduino-compatible boards and his business card. Success again.
Finally he went full out. Since the input rollers to the laminator are soft silicone it can apparently accommodate a fair amount of variance in height. He threw a full noise maker keyboard with resistive pads and a USB cable into the assembly. No issue.
It seems like a pretty good technique for making keyboards, weather proof circuits, and more.
Filed under: tool hacks
Gianni Bernardo has published a tutorial for usage of DHT22 sensor with a PICmicro (machine translation).
Tutorial about DHT22 / AM2302 Digital Humidity and Temperature sensor usage on picmicro, using XC Compiler. Code is for a PIC12F1822, data from sensor are formatted and sent on UART @9600baud
Source code is available on github.
Via the contact form.
Although many of us may have had childhood aspirations to be a famous wrestler in the WWE, not very many of us will ever realize those dreams. You can get close, though, if you have your own epic intro music theme that plays anytime you walk into a room. Although it’s not quite the same as entering a wrestling ring, [Matt]’s latest project will have you feeling just as good whenever you enter a room to your own theme song.
The core of the build consists of a boom box with an auxiliary input. The boom box is fed sound via a Raspberry Pi which also serves as the control center for the rest of the project. It runs Node.js and receives commands via websockets from a publicly accessible control server. The Pi is also running Spotify which allows a user to select a theme song, and whenever that user’s iBeacon is within range, the Pi will play that theme song over the stereo.
The project looks like it would be easy to adapt to any other stereo if you’re looking to build your own. Most of the instructions and code you’ll need are available on the project’s website, too. And, if you’re a fan of music playing whenever you open a door of some sort, this unique project is clearly the gold standard. It might even make Stone Cold Steve Austin jealous.
Filed under: musical hacks
The Google app for Android lets you use your voice to search the web, set reminders, open apps, and do a lot of other things. You can use it by tapping the microphone icon on your phone, but if you enable “OK Google” hotword detection, you can also interact with your phone without ever touching it… assuming you’re willing to put up with a little extra battery drain and the chance that your phone might mishear something else you’ve said and start trying to answer questions when you aren’t asking.
Hallucination is the erroneous perception of something that’s actually absent – or in other words: A possible interpretation of training data. Researchers from the MIT and the UMBC have developed and trained a generative-machine learning model that learns to generate tiny videos at random. The hallucination-like, 64×64 pixels small clips are somewhat plausible, but also a bit spooky.
The machine-learning model behind these artificial clips is capable of learning from unlabeled “in-the-wild” training videos and relies mostly on the temporal coherence of subsequent frames as well as the presence of a static background. It learns to disentangle foreground objects from the background and extracts the overall dynamics from the scenes. The trained model can then be used to generate new clips at random (as shown above), or from a static input image (as shown in pairs below).
Currently, the team limits the clips to a resolution of 64×64 pixels and 32 frames in duration in order to decrease the amount of required training data, which is still at 7 TB. Despite obvious deficiencies in terms of photorealism, the little clips have been judged “more realistic” than real clips by about 20 percent of the participants in a psychophysical study the team conducted. The code for the project (Torch7/LuaJIT) can already be found on GitHub, together with a pre-trained model. The project will also be shown in December at the 2016 NIPS conference.
Filed under: software hacks
Want to run Android apps on your Chromebook? Right now there are three models that can do that: and if you’re looking for a reasonably good deal on one, Groupon is selling a refurbished Acer Chromebook R11 convertible notebook with 4GB of RAM and a Celeron N3060 for $200.
That’s one of the best prices you’ll find right now for a Chromebook that already supports Android apps. But support is coming to dozens of additional Chromebooks in the coming months… and you can find plenty of new or refurbished Chrome OS laptops for even lower prices if you’re not hung up on the idea of getting one with a touchscreen display.
There are a number of ways to measure the speed of light. If you’ve got an oscilloscope and a few spare parts, you can build your own apparatus for just a few bucks. Don’t believe the “lies” that “they” tell you: measure it yourself!
OK, we’re pretty sure that conspiracy theories weren’t the motivation that got [Michael Gallant] to build his own speed-of-light measurement rig, but the result is a great writeup, and a project that includes one of our favorite circuits, the avalanche transistor pulse generator.
The apparatus starts off with a very quickly pulsed IR LED, a lens, and a beam-splitter. One half of the beam takes a shortcut, and the other bounces off a mirror that is farther away. A simple op-amp circuit amplifies the resulting pulses after they are detected by a photodiode. The delay is measured on an oscilloscope, and the path difference measured with a tape measure.
If you happen to have a photomultiplier tube in your junk box, you can do away with the amplifier stage. Or if you have some really fast logic circuits, here’s another project that might interest you. But if you just want the most direct measurement we can think of that’s astoundingly accurate for something lashed up on breadboards, you can’t beat [Michael]’s lash-up.
Oh and PS: He got 299,000 (+/- 5,000) km/sec.
Filed under: misc hacks
There’s good news and bad news for folks that have been waiting for new features to hit their Android Wear smartwatches. The good news is that Android Wear Developer Preview 3 is now available and it does have some new goodies, including the ability to browser the Google Play Store for smartwatch apps on your smartwatch (rather than by using your phone).
The bad news? Google has decided to extend the preview program… which means that the company won’t officially release Android Wear 2.0 until early 2017.
For the next post in the Creating A PCB series, we’re going to continue our explorations of Eagle. In Part 1, I went over how to create a part from scratch in Eagle. In Part 2, we used this part to create the small example board from the Introduction.
This time around I’ll be going over Design Rule Check (DRC) — or making sure your board house can actually fabricate what you’ve designed. I’ll also be covering the creation of Gerber files (so you can get the PCB fabbed anywhere you want), and putting real art into the silkscreen and soldermask layers of your boards.
The idea behind this series is to explore different EDA suites and PCB design tools by designing the same circuit in each. You can check out the rest of the posts in this series right here.DRC – Design Rule Check What happens when you don’t run a DRC. Image credit: Quinn Dunki
Board houses can’t produce PCBs with infinite resolution. There are limits to their process and when designing a PCB you can’t put traces too close together. The limits for each board house should be available somewhere on their web page, but generally you’re looking at a minimum trace width of 6 to 8 mil, a minimum trace separation of 6 to 8 mil, and a minimum drill size of 0.3 to 0.5 mm (about 12 to 20 mil). OSHPark is one of the better board houses with 5 mil width, 5 mil clearance, and 10 mil drills.
The Design Rule Check, or DRC, is how you find traces that are too small, too close together, or traces that simply overlap. This is how you check your board for errors before sending it off to a fab. That’s not to say the DRC in the current version of Eagle is good; KiCad has live DRC that is constantly checking your board. Eagle’s requires you to press a few buttons. This will change in the next few releases, though.
Get into the DRC by selecting ‘Tools’ -> ‘DRC in the board window. Something like this will pop up:
In the DRC window, you can set the minimum trace width for your project. The default is 8 mil, which is well within the capability of just about any board house. If you’re etching at home, you might want to bump this up a bit higher. For now, 8 mil separation is just fine, as are the rest of the default settings. Click through the tabs, and just see what options are available to you. There’s a ‘Check’ button at the bottom of this window. Click that, and you’re presented with all the errors you made.
When I ran the DRC on this project board, I had only one error relevant to this tutorial. The via I used to connect the VCC pin on the USB connector was too small. This drill was still well within the capabilities of OSHPark and Seeed, so I just clicked ‘Approve’. If your traces are too close together, or if they’re too close to a pad, the DRC will tell you.
It is imperative to run a DRC check before sending a board file off to a fab house. Not only will it help you stay within spec for the fab you are using, it will help catch silly errors that managed to get past you in the layout process.Gerbers for Sending the PCB Off to Fab
If you’re only making two-layer boards and sending them off to OSHPark, Seeed, or DirtyPCBs, there is no need to do anything else to have your boards made. All of the usual online board houses accept Eagle .brd files. If you’re using any of these services, you can drag and drop your board file on the order page. It’s dead simple and almost foolproof.
But the Eagle .brd file is not the industry-standard way of having a board fabricated. If you ever need a thousand PCBs, are making 6 (or more) layer PCBs, or just have some strange requirement, you’ll want to consider Advanced Circuits, Gold Phoenix, and numerous other options for fabrication. That means you’ll have to turn your board into a Zip archive full of Gerber files.
‘Gerbers’ are a collection of files that define each layer of the board. The top layer of copper is its own file, the top silkscreen layer is its own file, the top soldermask is its own file, and if you’re extremely good, Gerber allows you to create a layer telling a robot where to apply solder paste.
Lucky for you — and because this guide is already too long — OSH Park has a wonderful guide along with the CAM files required to generate Gerber Files. I highly suggest using OSH Park’s CAM file for generating Gerbers. It will generate the following files:
- Top Layer filename.GTL
- Top Solder Mask filename.GTS
- Top Silkscreen filename.GTO
- Bottom Layer filename.GBL
- Bottom Solder Mask filename.GBS
- Bottom Silk Screen filename.GBO
- Board Outline filename.GKO
- Drills filename.TXT
Put all of these files into a folder and Zip it up. Inspect your Gerbers with one of a dozen different online Gerber viewers. That’s really all you need to know about generating Gerber files from your Eagle boards.That’s Eagle.
In several thousand words and three posts, we’ve gone over how to create a new, custom part in Eagle, draw a schematic, place those parts onto a board, draw traces, and send that board off to a fab. This is the bare minimum of an introduction to Eagle CAD. Now we can knock Eagle off the list of How To Create A PCB In Everything.
For the next few posts in this series, we’ll be taking a look at Fritzing. If you’ve been reading along with this series, you already know the right way to make a PCB in Eagle. Fritzing will teach you the wrong way. As always, we’re looking for suggestions on what pieces of software we should cover next. If you have an idea, leave a note in the comments.
Filed under: Hackaday Columns, how-to, Skills
Chinese company LeEco offers a range of products in its home country including smartphones, smart TVs, smart bicycles, and more. Now the company is getting ready to do the same thing in the United States.
LeEco has been showing off some of its China-only products at events in the US since the Consumer Electronics Show in January. This summer the company announced that it was acquiring Vizio, one of the biggest players in the US TV space.
A 40 dB attenuator project by Hartmut DK5LH.
Hartmut uses the attenuator to measure the power of his transmitter (2 watts) with a power meter for -80 dBm to -10 dBm
The attenuator is used to reduce the output power of the set to a value that is less than 0.1 milliwatt. (-10 dBm)
More details at PA1B’s QRPp blog.
Building a circuit from prototyping to printed circuit board assembly is within the reach of pretty much anyone with the will to get the job done. If that turns out to be something that everyone else wants, though, the job gets suddenly much more complex. This is what happened to [Conor], who started with an idea to create two-factor authentication tokens and ended up manufacturing an selling them on Amazon. He documented his trials and tribulations along the way, it’s both an interesting and perhaps cautionary tale.
[Conor]’s tokens themselves are interesting in their simplicity: they use an Atmel ATECC508A specifically designed for P-256 signatures and keys, a the cheapest USB-enabled microcontroller he could find: a Silicon Labs EFM8UB1. His original idea was to solder all of the tokens over the course of one night, which is of course overly optimistic. Instead, he had the tokens fabricated and assembled before being shipped to him for programming.
Normally the programming step would be straightforward, but using identical pieces of software for every token would compromise their security. He wrote a script based on the Atmel chip and creates a unique attestation certificate for each one. He was able to cut a significant amount of time off of the programming step by using the computed values with a programming jig he built to flash three units concurrently. This follows the same testing and programming path that [Bob Baddeley] advocated for in his Tools of the Trade series.
From there [Conor] just needed to get set up with Amazon. This was a process worthy of its own novel, with Amazon requiring an interesting amount of paperwork from [Conor] before he was able to proceed. Then there was an issue of an import tariff, but all-in-all everything seems to have gone pretty smoothly.
Creating a product from scratch like this can be an involved process. In this case it sounds like [Conor] extracted value from having gone through the entire process himself. But he also talks about a best-case-scenario margin of about 43%. That’s a tough bottom line but a good lesson anyone looking at building low-cost electronics.
Filed under: hardware
What Apple taketh away, third-party smartphone case makers giveth back. Fuze is a smartphone case for the iPhone 7 and iPhone 7 Plus that features a 3.5mm headphone jack.
The new case also has a built-in battery, allowing you to squeeze some extra run time out of the phones.
Fuze isn’t actually available yet: but the makers of the case are running a crowdfunding campaign on Indiegogo and offering cases as rewards for $69 (or less if you score one of the early bird specials).
After HP blocks third-party ink from working with printers, company promises optional update to remove the ban
A few weeks ago HP activated a firmware update for many of its recent printers. The company said the update was meant to “ensure the best consumer experience,” but what the update did was stop HP’s printers from working with third-party ink cartridges.
Even customers who had already purchased those cartridges, put them in their printers, and used them for months found that after the update they could no longer print.
This left many users frustrated, and the Electronic Frontier Foundation called on HP to roll back the update and promise never to describe this sort of thing as a “security” update again.
Now it’s official. The particular website that was hit by a record-breaking distributed denial of service (DDOS) attack that we covered a few days ago was that of white-hat security journalist [Brian Krebs]: Krebs on Security.
During the DDOS attack, his site got 600 Gigabits per second of traffic. It didn’t involve amplification or reflection attacks, but rather a distributed network of zombie domestic appliances: routers, IP webcams, and digital video recorders (DVRs). All they did was create HTTP requests for his site, but there were well in excess of 100,000 of these bots.
In the end, [Krebs’] ISP, Akamai, had to drop him. He was getting pro bono service from them to start with, and while they’ve defended him against DDOS attacks in the past, it was costing them too much to continue in this case. An Akamai exec estimates it would have cost them millions to continue defending, and [Brian] doesn’t blame them. But when Akamai dropped the shields, his hosting provider would get slammed. [Krebs] told Akamai to redirect his domain to localhost and then he went dark.The Democratization of Censorship
[Krebs’] takeaway from the whole event is summarized in his blog post (now that he’s back online): “The Democratization of Censorship“. It’s worth a read, and we’re not going to try to one-up [Brian Krebs]. His basic point, however, is that it used to take a nation-state to censor information on the Web — strongman regimes or agencies with spooky contacts in big ISPs. But if any script-kiddie can leverage IoT devices with hardcoded passwords to pull selected websites off the Net, the game has fundamentally changed.
You’d have to be a fairly dedicated anarchist to say that this is a good development. After all, we haven’t traded government censorship and surveillance for private censorship. There’s just another actor on the stage, and what’s worse, that other actor is criminal. We understand that [Krebs] meant it in an ironic sense, but “democratization” is such a nice word that we hate to see it used here.
[Krebs] also makes the case that sufficiently motivated groups can now effectively silence journalists, and makes the case for thinking about how we can protect free speech on the Internet. For his part, [Krebs] is now hosted as part of a Google project (Project Shield) that aims to mitigate such attacks. (Ironically, Google still thinks of its adversary as “powerful institutions” rather than “some dude in his basement”.)Organized Crime
The timing makes it look like it was the “vDOS” folks who were selling DDOS services, and two of whom are now in jail. They had a beef with [Brian] and they took him down. But while in [Krebs’] case it probably was personal and an issue of censorship, in the majority of cases it’s just about money.
In the last few years, ransomware has become so widespread that people outside the security community have even heard of it. But DDOS ransom attacks are the true growth industry. And these extortionists even have cute nicknames now: “booters” or “stressers”.
[Krebs] estimates that getting DNS services that will protect him in the event of a similar attack would cost him $100,000 to $300,000 per year. Clearly, he’s not able to fork out that much for legit protection, but the cost of protection against this sort of attack should provide an upper bound on how much ransom these criminals can ask for. As another data point, the ransom note delivered to ProtonMail suggests that the actual street price is as low as twenty Bitcoin — around $12,000. (They got hit, customers complained, and they paid.)
The point is that one could make a good living running a botnet of DVRs, threatening to knock websites off the Internet for a day or two. We see this as a much more likely threat than [Krebs’] fear of censorship. DDOS extortion is illegal and wrong, but where there’s money, there’s going to be a criminal to fit the crime.Why? Why Not?
Given that botnets of DVRs can be converted into cash, [Krebs] was asked why he thought anyone would do this. Before the attack, whoever was running the IoT botnet had 100,000+ computers under their control, all of which were entirely under the radar. But now the IP addresses of all of these machines are known, and someone might get around to patching the devices someday. Who would burn a gigantic botnet just to make [Brian] mad?
[Krebs’] answer is terrifying, but probably spot-on. It doesn’t matter who launched the attack. There are tens of millions of insecure IoT devices out there. Using up 100,000 here or there is a drop in the ocean. Of the bazillions of IoT devices coming online this year, how many have hardcoded administrator passwords right now? How many will be found to be vulnerable to yet-unknown attacks in the near future?
We also cynically think that hitting [Brian Krebs] is good advertising for the groups who are selling DDOS extortion — if there was a single sysadmin who hadn’t heard of the concept, they will have now. Akamai touting the cost of defending against this sort of attack is the best publicity that the “booters” could have hoped for. Scale your botnet up, hit a rich target, and maybe you can approach the $100,000 payoff. (Not an actual suggestion.)
Whatever the motive, there are millions of unpatched routers and DVRs out there waiting to enlist in the next botnet. In June 2016, Sucuri wrote about defending against a “large” botnet of only 25,000 CCTV appliances. In August, Level 3 wrote about vulnerabilities in over one million units of one brand of DVR. What counts as a “large” botnet has quadrupled over a few months, and the amount of traffic that one can generate has kept pace. And all of this is just the tip of the iceberg.Tiny Headless Servers Everywhere
The problem is one that we’ve written about before, more or less obliquely. IoT devices contain headless computers that are connected to the Internet and talking to the outside world without human oversight. They’re what the layman thinks of as servers: a “box” somewhere with no GUI, accessed remotely, and dishing out data 24/7. The important difference between an IoT device and a traditional server is that the bigger server has an administrator who can apply patches and software tools that help him or her keep an eye on things.
With IoT devices, the ability to update, upgrade, audit, and administer is still in its infancy. The root passwords to some of the DVR devices used in this attack have been known since 2013, and scriptable attacks against the devices are included as a Metasploit module. A competent sysadmin would have patched that by now. (And a competent manufacturer never would have let that out the door.)
Instead the devices are administered by (millions of) people who don’t even really know that there’s a tiny little computer inside. These are people who have no idea about downloading and flashing firmware upgrades, or don’t understand they need to do so for a webcam.
Stereotypes abound, and as relatively sophisticated users we might feel smug. But are you 100% sure that there have been no firmware updates available for your router in the last couple months? We have better things to do than babysit our devices.How to Fix It? vDOS’s Website, with prices
The security problem of IoT appliances is real, and it has nothing to do with Big Brother using your Nest to tell what temperature it is now in your living room, not that we like that either. Exploiting botnets of IoT devices has become a viable criminal option. Unpatched IoT appliances are the (pre-service-pack-two) Windows XP machines of the moment: they’re a public menace because they enable criminal activity. And it’s going to take both industry involvement and user education to get us out of this mess.
One solution is remote-push firmware upgrades. Of course, this is its own avenue for malware distribution, but it might be less dangerous than leaving hard-coded administrator passwords in place, or running outdated software with known exploitable bugs. There are a number of known bad ways to implement this: a single key for all devices “hidden” in the EEPROM, for instance. What are the good ways?
People don’t like change, though, and heavy-handed (hello, Windows 10!), late, or failed push updates give the whole mechanism a bad rap. And companies go out of business or simply decide to pull support for their products. Other firms just don’t care. We can’t rely on businesses to secure our devices in perpetuity when they have no financial incentive to do so.
In short, the consumer IoT botnet problem is a thorny one, and it’s not one that we’ve heard the last of. What do we do?
Filed under: Current Events, Featured, Original Art, security hacks
Every now and then a hacker gets started on a project and forgets to stop. That’s the impression we get from [HBPowerwall]’s channel anyway. He’s working on adding a huge number of 18650 Lithium cells to his home’s power grid and posting about his adventures along the way. This week he gave us a look at the balancing process he uses to get all of these cells to work well together. Last month he gave a great overview of the installed system.
His channel starts off innocently enough. It’s all riding small motor bikes around and having a regular good time. Then he experiments a bit with the light stuff, like a few solar panels on the roof. However, it seems like one day he was watching a news brief about the Powerwall (Tesla’s whole-home battery storage system) and was like, “hey, I can do that.”
After some initial work with the new substance it wasn’t long before he was begging, borrowing, and haggling for every used 18650 lithium battery cell the local universe in Brisbane, Australia could sell him. There are a ton of videos documenting his madness, but he’s all the way up to a partly off-grid house with a 20kWh battery bank, for which he has expansion plans.
There’s a lot of marketing flim flam and general technical pitfalls in the process of generating your own non-grid electricity. But for hackers in sunny areas who want to dump those rays into local storage this is an interesting blueprint to start with.
Filed under: home hacks, solar hacks
How much access do you have to a 3D printer? What would you do if you had weeks of time on your hands and a couple spools of filament lying around? Perhaps you would make a two second stop-motion animation called Bears on Stairs.
An in-house development by London’s DBLG — a creative design studio — shows a smooth animation of a bear — well — climbing stairs, which at first glance appears animated. In reality, 50 printed sculptures each show an instance of the bear’s looping ascent. The entire process took four weeks of printing, sculpture trimming, and the special diligence that comes with making a stop-motion film.
The heart of the project was to experiment, create, and — most importantly — have fun. So while these stairs don’t appear to go anywhere, in practice they flex and test the creative spirit inherent in any maker. Plus, the fusion of 3D printing and stop-motion make for pleasant viewing. If you want to check out a comparatively ‘feature length’ stop motion animation, check out The Rabbit’s Hole.
Filed under: Uncategorized
It’s a common problem faced by TV viewers, the programming they want to watch is being broadcast, but not to their location. TV content has traditionally been licensed for transmission by geography, and this has sometimes put viewers at odds with broadcasters.
The viewing public have not always taken this restriction of their programming choice lying down, and have adopted a variety of inventive solutions with varying degrees of legality and success. Many years ago you might have seen extreme-length UHF antennas to catch faraway transmitters, more recently these efforts have been in the digital domain. It was said in the 1990s that Sky’s Videocrypt satellite TV smart cards were cracked because German Star Trek Next Generation fans were unable to buy subscriptions for non-UK addresses, for example. You can argue in the comments over whether [Patrick Stewart] et al being indirectly responsible for a decryption coup is an urban legend, but it is undeniable that serial smart card emulators and dodgy DOS software for Sky decryption were sold all over Europe at the time.
Modern-day efforts to break the geographic wall on TV broadcasting have turned to the Internet. Services such as the ill-fated Aereo and the Slingbox set-top streaming products have taken the TV broadcast in a particular area and transported it to other locations for viewing online. But they are not the only Internet self-streaming option, if the idea of paying a subscription or tying yourself to a commercial service does not appeal then you can build an off-air streamer for yourself.
[Solenoid]’s project is an off-air streamer using a Raspberry Pi 3 with a USB DVB-T tuner. It uses Tvheadend to power the streaming, and OpenVPN to provide security. His build logs detail his efforts to ensure that power consumption is not too high and that the Pi is not running too hot, and provides instructions on how to set up and use the software. It’s not an overly complex piece of hardware, but it could provide a useful service for any of you who wish to keep up-to-date with your home TV when you are off on your travels.The HackadayPrize2016 is Sponsored by:
Filed under: video hacks
Students from the Indian Institute of Science Education and Research combined a commercial satellite dish, a satellite finder and an Arduino, and produced a workable radio telescope. The satellite dish provides the LNB (low noise block) and the associated set-top box is used only for power. Their LNB employs an aluminum foil shield to block extraneous signals.
In addition to the hardware, the team built Python software to analyze the data and show several practical applications. They used known geostationary satellites to calibrate the signal from the finder (digitized by the Arduino) to determine power per unit voltage. They also calculated the beam width (about 3.4 degrees) and used the sun for other calibration steps.
The paper notes that some designs use the ubiquitous RTL-SDR, but this limits the bandwidth to about 3 MHz. The satellite finder detector is inherently broadband and the team claims a bandwidth for their scope of 1.1 GHz. Some designs (like the Itty Bitty) use a dual LNB to have both. If you are too lazy to build any hardware, you can still get into the radio telescope data crunching game.
If you want an introduction to radio astronomy, you might enjoy Dr. John Morgan’s lecture, in the video below.
Filed under: Arduino Hacks, radio hacks