Abraham Wald’s Problem Solving Lesson Is To Seek What’s Not There

August 1, 2019 by Al Williams 26 Comments

You may not know the name Abraham Wald, but he has a very valuable lesson you can apply to problem solving, engineering, and many other parts of life. Wald worked for the Statistical Research Group (SRG) during World War II. This was part of a top secret organization in the United States that applied elite mathematical talent to help the allies win the war. Near Columbia University, mathematicians and computers — the human kind — worked on problems ranging from how to keep an enemy plane under fire longer to optimal bombing patterns.

One of Wald’s ways to approach problem was to look beyond the data in front of him. He was looking for things that weren’t there, using their absence as an additional data point. It is easy to critique things that are present but incorrect. It is harder to see things that are missing. But the end results of this technique were profound and present an object lesson we can still draw from today.

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Supercon CFP Extended By Two Weeks

August 1, 2019 by Mike Szczys 6 Comments

Need a bit more time to submit your talk proposal for the 2019 Hackaday Superconference? Okay, but we can only do this once. You now have until August 16th to submit your proposal.

Supercon is the ultimate hardware conference. Take all the best conversations you’ve had about electronics, firmware development, industrial design, art, music, and culture and pack them into three incredible days in Pasadena. That’s the start of what you’ll find at this event. There is no substitute for experiencing it in person.

What makes this so unique is the people who show up. We are forever on the search of people with clever, compelling, delightful, and bizarre stories about hardware creation… and that means you. Yes, you! Supercon is a great place to give your first-ever conference talk. Package up the details of your recent hardware adventures and send them in as a proposal. The biggest mistake we see people make is assuming nobody wants to hear about what’s going on in their workshop or lab. Long talk or short talk, we want to hear your talk!

Take the plunge, the water is warm the so are the soldering irons which run constantly in the Hacker Village that forms during Supercon. There are still tickets available, but of course, speaker receive our undying gratitude and of course, free admission.

Machinist Tools: Edge Finding

July 31, 2019 by Quinn Dunki 35 Comments

Machinists like to live on the edge, but they always want to know precisely where it is. If you’ve watched any machining videos (*cough*) then you’ve seen heavy use of digital readouts on machines. A “DRO” (as the cool kids call them) is a little computer that knows where the slides are, and thus where your cutter is on the piece. However, there’s a catch. DROs don’t know the absolute position of the spindle, they know the relative position of it. The bottom line is that a DRO is just a fancier version of the graduated scales on the hand wheels. The key difference is that the DRO doesn’t suffer from backlash, because it is measuring the slides directly (via glass scales similar to your digital caliper) rather than inferring position from rotations of the leadscrews. With traditional hand wheels, you have to compensate for backlash every time you change direction, and a DRO saves you from that (among other convenience features).

The point is that, whether old school or new, you still only get a relative coordinate system on your part. You need to establish an origin somehow. A useful way to do this is to set an origin at one corner of the part, based on its physical edges. How do you tell the DRO (or hand wheels) where the edges are? Enter the edge finder.

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Teardown: Catel CTP300 Restaurant Pager

July 30, 2019 by Tom Nardi 39 Comments

I have a problem. If I go to a swap meet , or even a particularly well stocked yard sale, I feel compelled to buy something. Especially if that something happens to be an oddball piece of electronics. While on the whole I’m a man of few vices, I simply can’t walk away from a good deal; doubly so if it has a bunch of buttons, LEDs, and antennas on it.

Which is exactly how I came into the possession of a Catel CPT300 restaurant paging system for just $20 a few months ago. I do not, as you may have guessed, operate a restaurant. In fact, as many of my meals take the form of military rations eaten in front of my computer, I’m about as far away from a restaurateur as is humanly possible. But I was so enamored with the rows of little plastic pagers neatly lined up in their combination charging dock and base station that I had to have it.

The man selling it swore the system worked perfectly. Even more so after he plugged it in and it didn’t do anything. But appearances can be deceiving, and his assurance that all the pagers needed was a good charge before they’d burst back to life seemed reasonable enough to me. Of course, it hardly mattered. The regular Hackaday reader at this point knows the fate of the CPT300 was to be the same whether or not it worked.

Incidentally, those cute little pagers would not burst back to life with a good charge. They may well have burst into something, but we’ll get to that in a moment. For now, let’s take a look at a gadget that most of us have used at one time or another, but few have had the opportunity to dissect.

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Hands-On: AND!XOR DEF CON 27 Badge Ditches Bender, Adopts Light Pipes

July 29, 2019 by Mike Szczys 13 Comments

The newest offering from the AND!XOR team is out and it delivered exactly what hardware badges were missing: light pipes. No joke, the DEF CON 27 edition AND!XOR badge will be most recognizable because of two arcs of light pipe material blinging RGB goodness in three dimensions. But if you can peel your eyes away from that oddity there’s a lot to love about the new design.

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Quick-Turn PCB Fab Hack Chat

July 29, 2019 by Dan Maloney No comments

Join us on Wednesday, July 31st at noon Pacific for the Quick-Turn PCB Fab Hack Chat with Mihir Shah!

We’ve all become used to designing a PCB and having it magically appear at our doorstep – after a fashion. Modern PCB fabs rely on economies of scale to deliver your design cheaply, at the expense of time – the time it takes to put enough orders onto a panel, and the time it takes to ship the finished boards from Far, Far Away.

Not everyone has that kind of time to burn, though. That’s where quick-turn fabs come in. These manufacturers specialize in getting boards to their customers as quickly as possible, helping them deal with sudden design changes or supporting specialty applications for customers.

It’s a niche industry, but an important one, and Royal Circuits is at the forefront. Mihir Shah is Director of Special Projects there, and he’s deep into the business of getting PCBs to customers as quickly as possible. He’ll drop by the Hack Chat to answer all your questions about how the quick-turn industry fits into the electronics manufacturing ecosystem, and to show off some of the tools of the future that they’re developing and investing in to streamline PCB design and analysis – from DebuggAR to PCBLayout.com, and more.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday July 31 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Fail Of The Week: The Arduino Walkie That Won’t Talkie

July 28, 2019 by Dan Maloney 33 Comments

There’s something seriously wrong with the Arduino walkie-talkie that [GreatScott!] built.

The idea is simple: build a wireless intercom so a group of motor scooter riders can talk in real-time. Yes, such products exist commercially, but that’s no fun at all. With a little ingenuity and a well-stocked parts bin, such a device should be easy to build on the cheap, right?

Apparently not. [GreatScott!] went with an Arduino-based design, partly due to familiarity with the microcontroller but also because it made the RF part of the project seemingly easier due to cheap and easily available nRF24 2.4 GHz audio streaming modules. Everything seems straightforward enough on the breadboard – an op-amp to boost the signal from the condenser mic, a somewhat low but presumably usable 16 kHz sampling rate for the ADC. The radio modules linked up, but the audio quality was heavily distorted.

[GreatScott!] assumed that the rat’s nest of jumpers on the breadboard was to blame, so he jumped right to a PCB build. It’s a logical step, but it seems like it might be where he went wrong, because the PCB version was even worse. We’d perhaps have isolated the issue with the breadboard circuit first; did the distortion come from the audio stage? Or perhaps did the digitization inject some distortion? Or could the distortion be coming from the RF stage? We’d want to answer a few questions like that before jumping to a final design.

We love that [GreatScott!] has no issue with posting his failures – we’ve covered his suboptimal CPU handwarmer, and his 3D-printed BLDC motor stator was a flop too. It’s always nice to post mortem these things to avoid a similar fate.

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