When Are Dumb LEDs The Smart Choice?

September 4, 2018 by 25 Comments

A couple years ago I got into making electronic conferences badges by building a device for DEFCON 25 shaped like a dragonfly. Like all badges the most important design factor was quite literally how flashy it was, and two years ago I delivered on that with ten RGB LEDs. At the time I planned to hand-assemble each and every of the 105 badges at my kitchen table. Given those constraints, and a desire for electrical and programmatic simplicity, I landed on using APA102s (DotStar’s in Adafruit parlance) in the common 5050 sized package. They were easy to place, easy to design with electrically, simple to control, and friendly to a human pick-n-place machine. Though by the end of the production run I had discovered a few problems, the APA102s were a success.

This year I made a new and improved version of the dragonfly, but applying my lessons learned led me to choose a very different LED architecture than 2017. I swapped out the smart LEDs for dumb ones.

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Pushing Tin Remotely: The Start Of Flight Control In The Cloud

September 4, 2018 by 59 Comments

In a 1999 movie (Pushing Tin), a flight controller is a passenger on a plane and tells the flight attendant that he needs to speak to the person controlling the plane. The flight attendant tells him the pilot is very busy to which the controller responds, “…you really think the pilot is controlling this plane? That would really scare me.” We wonder what that fictional character would think flying into Loveland Colorado. Their Colorado Remote Tower Project. While there’s still a human flight controller, they aren’t physically located at the airport and rely on remote cameras and radar so the controller can be located elsewhere.

The subject airport is the Northern Colorado Regional Airport and is the state’s busiest airport that has no tower. While the concept — generically known as Remote and Virtual Tower or RVT — dates back to 2002, its adoption is only now starting to pick up steam. An airport in Sweden was the first to go live for normal use in April of 2015, but the Colorado installation is the first approved in the United States. If the official site is a little too dry for you, there’s a CBS report with a video that gives you a quick overview of what’s happening. Or dive in with the demonstration video you can see below.

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sigrok I2C screenshot

Doing Logic Analysis To Get Around The CatGenie’s DRM

September 4, 2018 by 53 Comments

The CatGenie is an amazing device to watch in action, basically a self-cleaning litter box for cats that even does away with the need to replace the litter. It’s comparable to what the indoor flush toilet is for humans compared to maintaining a composting toilet. However, there is a problem. It uses costly soap cartridges which have to be replaced because an RFID reader and a usage counter prevent you from simply refilling them yourself.

CatGenie and Arduino
CatGenie and Arduino

[David Hamp-Gonsalves] reverse engineered the electronics so that he didn’t have to pay for the cartridges anymore. This has been done before and one of those who did it created a product called the CartridgeGenius, but it’s made and sold as a parttime project and there were none in stock. The cartridges have an RFID tag and another solution which we’ve covered before is to replace the RFID reader board with an Arduino. That’s the solution [David] adopted. So why write this post if this isn’t new?

The RFID reader board communicates with the rest of the CatGenie using I2C and he needed to know what was being transmitted. To do that he learned how to use a cheap logic analyzer to read the signals on the I2C wires, which makes this an interesting story. You can see the logic analyser output on his blog and GitHub repository along with mention of a timing issue he ran into. From what he learned, he wrote up Arduino code which sends the same signals. He and his cat are now sitting pretty.

What he didn’t do is make a video. But the CatGenie really is amazing to watch in action as it goes through its rather complex 30-35 minute process so we found a video of it doing its thing, shown at 3.5x speed, and included that below.  If you’re into that sort of thing.

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Live Streaming Goes Pro With A Hacked Backpack

September 3, 2018 by 11 Comments

If you haven’t been paying attention, live streaming has become a big business. Streamers are getting out of their basements and moving around among us. While IRL streams may not be our cup of tea, the technology behind creating a solid high upstream bandwidth wireless internet connection is. Sure you can stream with a phone, the top streamers want something a bit more reliable. Enter [Gunrun], who has designed a backpack just for mobile streaming.

The backpack starts with a Sony AS300  Camera. [Gunrun] likes this particular camera for its exceptional audio capabilities. Network connections are handled with no less than four LTE modems. You never know which carrier will have good service out in the field, so the modems are available from a variety of carriers.

The real problem is bonding connections between LTE modems from various carriers, setting up streaming accounts, and piping captured data from an HDMI capture over those accounts. The average hacker would go at it with an HDMI capture card and a Linux Laptop. Most streamers need a more plug and play solution though, so [Gunrun] uses a LiveU Solo HDMI video encoder for the task.

This isn’t a cheap solution, all those parts together along with a beefy battery, LTE data plans, and of course a backpack to hold it all makes for a package north of $2000. Even at this price, plenty of streamers have been following [Gunrun’s] instructions and building their own setup.

Hackers do a bit of live streaming too – check out how [cnlohr] reverse engineered the Vive, while valve engineers played along in the chat.

Visualizing Verilog Simulation

September 3, 2018 by 16 Comments

You don’t usually think of simulating Verilog code — usually for an FPGA — as a visual process. You write a test script colloquially known as a test bench and run your simulation. You might get some printed information or you might get a graphical result by dumping a waveform, but you don’t usually see the circuit. A new site combines Yosys and a Javascript-based logic simulator to let you visualize and simulate Verilog in your browser. It is a work in progress on GitHub, so you might find a few hiccups like we did, but it is still an impressive piece of work.

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There Is A Cost To Extended Lifetime Products. It’s 7.5%.

September 3, 2018 by 43 Comments

Silicon and integrated circuits come and go, but when it comes to extended lifetime support from a company, it’s very, very hard to find fault with Microchip. They’re still selling the chip — new — that was the foundation of the Basic Stamp. That’s a part that’s being sold for twenty-five years. You can hardly find that sort of product support with a company that doesn’t deal in high-tech manufacturing.

While the good times of nearly unlimited support for products that are decades old isn’t coming to an end, it now has a cost. According to a press release from Microchip, the price of these old chips will increase. Design something with an old chip, and that part is suddenly going to cost you 7.5% more.

The complete announcement (3MB PDF), states, in part:

…in the case of extended lifecycle product offerings, manufacturing, assembly and carrying costs are increasing over time for
these mature technology products and packages. Rather than discontinue our mature product, Microchip will continue to support our
customer needs for product availability, albeit increasing the prices in line with increased cost associated with supporting mature
product lines….

For all orders received after 31 August, pricing for the products listed will be subject to an increase of 7.5%

The PDF comes with a list of all the products affected, and covers the low-end ATtinys, ATMegas, and PICs that are used in thousands of tutorials available online. The ATtiny85 is not affected, but the ATMega128 is. There are a number of PICs listed, but a short survey reveals these are low-memory parts, and you really shouldn’t be making new designs with these anyway.

The Quest For High Powered Blinky And Buzzing

September 3, 2018 by 3 Comments

Sometimes, we need devices to notify us of something. The oven timer is going off. Your phone has a push notification. The smoke detector battery is getting low. All of these problems can be solved with a buzzer or an LED. It’s a simple and cheap problem to solve.

But what if you need to know if something’s wrong with a diesel engine that throwing out 90 dB of noise? What if you’re not guaranteed to be around that engine? What if you need to tell everyone within a half mile that something is wrong. Again, LEDs and beepers, but the standard, off-the-shelf implementation isn’t going to cut it. You need massive amounts of buzzers and LEDs, and you’re going to need to drive them all with some reasonably high current. How do you solve that problem?

This is the problem [Tegwyn] had to solve for another one of his Hackaday Prize entries. The solution is what you would expect — buzzers and LEDs — but he’s putting some serious current behind these devices. There are, in fact, thermal considerations taken into account when you’re beeping this many buzzers.

The LEDs for this project are a handful of blindingly bright 1209 and 1206 SMD parts, and the buzzer is an obnoxiously loud SMD 97 dB buzzer. There are eight buzzers on this board. So, how do you drive these power-hungry devices? [Tegwyn] is using an L293E half-bridge motor driver, in a ‘Power-DIP’ package for relatively effective heat dissipation. Does it work? Oh, yes, and it’s very annoying. Take a look at the video below and judge for yourself. You can, indeed, make something louder and more annoying by adding more power.

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