Duck And Cover With This WiFi “Geiger Counter”

April 8, 2019 by 10 Comments

There’s perhaps no sound more recognizable than the frantic clicking of a Geiger counter. Not because this is some post-apocalyptic world in which everyone is personally acquainted with the operation of said devices, but because it’s such a common effect used in many movies, TV shows, and video games. If somebody hears that noise, even if it doesn’t really make sense in context, they know things are about to get serious.

Capitalizing on this phenomena, [Anton Haidai] has put together a quick hack which turns the ESP8266 into a “Geiger counter” for WiFi. Rather than detecting radiation, the gadget picks up on the strongest nearby WiFi signal and will start clicking in response to signal strength. As the signal gets stronger, so does the clicking. While primarily a novelty, it’s an interesting idea that could potentially be useful for things like fox hunting.

The hardware is really about as simple as it gets, just a basic buzzer attached to one of the digital pins on a NodeMCU development board. This project is more of a proof of concept, but if it were to be developed further it would be interesting to see the electronics placed into a 3D printed replica of one of the old Civil Defense Geiger counters. Perhaps even integrating an analog gauge that can bounce around in response to signal strength.

Software-wise there is the option of locking onto one single network SSID or allowing the device to find the strongest network in the area. Even if you’re not in the market for a chirping WiFi detector, the code is a good example of how you can detect signal RSSI and act on it accordingly; a neat trick which might come in handy in a future project.

If you’re more interested in the real thing, we’ve got plenty of DIY Geiger counters in the archive for you to check out. From diminutive builds that can be mounted to the top of a 9V battery to high-tech solid state versions with touch screen interfaces, you should have plenty of inspiration if you’re looking to kit yourself out before your next drive through the Chernobyl Exclusion Zone.

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Metal 3D Printing — A Dose Of Reality

April 8, 2019 by 19 Comments

We have no doubt that hundreds of times a day a hacker is watching a 3D printer spew hot plastic and fantasizes about being able to print directly using metal. While metal printers are more common than ever, they are still out of reach for most people printing as a hobby. But as Mr. Spock once observed: “…you may find that having is not so pleasing a thing after all as wanting. It is not logical, but it is often true.” However, metal 3D printing has its own unique set of challenges. Texas A&M recently produced a short video explaining some of the design issues that you’ll encounter trying to make practical metal prints on an SLS (Selective Laser Melting) printer. You can see the video below.

The description says “It is more challenging to ‘metal 3D print’ a part than most people think. We’ve noticed the same even with plastic printers as friends will expect us to print the most outlandish things for them. What we like about this video is it helps to set expectations of the current state of the art so we’re not expecting far more than today’s metal printers can produce.

Among the features covered in the video are overhangs, which require supports. After removal, the surface is about like 80 grit sandpaper unless you perform further finishing. Just like plastic parts, warping and curling of large areas is a problem with metal. If you’ve ever been frustrated removing plastic support material, try having to ceramic grind metal supports off. They also use an EDM machine to cut especially tough supports, but it causes a lot of effort since it is likely to run through EDM wires and clog the filters.

We looked at recent advances in metal printing last year. We’ve seen homebrew machines that were little more than welders under computer control and we’ve seen plans by big players like HP to create metal prints, but at a steep price. Still, you can’t stop the march of 3D printing progress.

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The 3D Printing Dream Is Still Alive At 2019’s Midwest RepRap Festival

April 8, 2019 by 8 Comments

3D Printers have been in the hands of hackers for well over ten years, but the dream is far from over and certainly not overslept. This year’s Midwest RepRap Festival is a testament to the still-growing excitement, and world where 3D printing is alive and kicking on the next level.

This past weekend, I took up my friend [Eric’s] advice to come down and participate firsthand, and I was simply blown away. Not only did we witness the largest number of attendees to date, MRRF 2019 spilled into not one but two conference halls at the Goshen Fairgrounds.

In what follows, I tell my tale of the times. Continue reading “The 3D Printing Dream Is Still Alive At 2019’s Midwest RepRap Festival” →

Autodesk Fusion 360 Hack Chat

April 8, 2019 by 20 Comments

Join us Wednesday at noon Pacific time for the Autodesk Fusion 360 Hack Chat!

Most of us have a collection of tools that we use for the various mechanical, electronic, and manufacturing tasks we face daily. But if you were asked to name one tool that stretches across all these spaces, Autodesk Fusion 360 would certainly spring to mind. Everyone from casual designers of 3D-printed widgets to commercial CNC machine shops use it as an end to end design solution, and anyone who has used it over the last year or so knows that the feature set in Fusion is expanding rapidly.

Matt, who goes by technolomaniac on Hackaday.io, is Director of Product Development for EAGLE, Tinkercad, and Fusion 360 at Autodesk. He’ll drop by the Hack Chat this week to discuss your questions about:

  • All the Autodesk design software components, from EAGLE to Fusion and beyond
  • Future plans for an EAGLE-Fusion integration
  • Support for manufacturing, including additive, CNC, and even mold making
  • Will there ever be “one design tool to rule them all?”

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Autodesk Fusion 360 Hack Chat page and we’ll put that in the queue for the Hack Chat discussion.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, April 10, at noon, 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.

Vintage Print Processor Fixed With 3D Printing

April 8, 2019 by 13 Comments

If you don’t know what a print processor is, don’t feel bad. There’s precious few people out there still running home darkrooms, and the equipment used for DIY film development is about as niche as it gets today. For those looking to put together their own darkroom in 2019, buying second hand hardware and figuring out how to fix it on your own is the name of the game, as [Austin Robert Hermann] found out when he recently purchased a Durst Printo Print Processor on eBay.

The auction said the hardware was in working order, but despite the fact that nobody would ever lie on the Internet, it ended up being in quite poor condition. Many of the gears in the machine were broken, and some were simply missing. The company no longer supports these 1990’s era machines, and the replacement parts available online were predictably expensive. [Austin] determined his best course of action was to try his hand at modeling the necessary gears and having them 3D printed; two things he had no previous experience with.

Luckily for [Austin], many of the gears in the Printo appeared to be identical. That meant he had several intact examples to base his 3D models on, and with some educated guesses, was able to determine what the missing gears would have looked like. Coming from an animation background, he ended up using Cinema 4D to model his replacement parts; which certainly wouldn’t have been our first choice, but there’s something to be said for using what you’re comfortable with. Software selection not withstanding, he was able to produce some valid STLs which he had printed locally in PLA using an online service.

Interestingly, this is a story we’ve seen play out several times already. Gears break and wear down, and for vintage hardware, that can be a serious problem. But if you’ve got a couple intact gears to go by, producing replacements even on an entry level desktop 3D printer is now a viable option to keep these classic machines running.

Brain Hacking With Entrainment

April 8, 2019 by 16 Comments

Can you electronically enhance your brain? I’m not talking about surgically turning into a Borg. But are there electronic methods that can improve various functions of your brain? Fans of brainwave entrainment say yes.

There was an old recruiting ad for electrical engineers that started with the headline: The best electronic brains are still human. While it is true that even a toddler can do things our best computers struggle with, it is easy to feel a little inadequate compared to some of our modern electronic brains. Then again, your brain is an electronic device of sorts. While we don’t understand everything about how it works, there are definitely electric signals going between neurons. And where there are electric signals there are ways to measure them.

The tool for measuring electric signals in the brain is an EEG (electroencephalograph). While you can’t use an EEG to read your mind, exactly, it can tell you some pretty interesting information, such as when you are relaxed or concentrating. At its most basic we’ve seen toys and simple hobby projects that purport to be “mind controlled” but only at an incredibly rudimentary level.

Brainwave entrainment is a hypothesis that sending low frequency waves to your brain can give your mind a nudge and sync up brain activity with the equipment measuring it. The ability to synchronize with the brain could yield much better measurements for a meaningful interface between modern electronics and electric storm of thought happening in your head.

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Give Your Raspberry Pi SD Card A Break: Log To RAM

April 8, 2019 by 82 Comments

The fragility of SD cards is the weak link in the Raspberry Pi ecosystem. Most of us seem to have at least one Pi tucked away somewhere, running a Magic Mirror, driving security cameras, or even taking care of a media library. But chances are, that Pi is writing lots and lots of log files. Logging is good — it helps when tracking down issues — but uncontrolled logging can lead to problems down the road with the Pi’s SD card.

[Erich Styger] has a neat way to avoid SD card logging issues on Raspberry Pi, he calls it a solution to reduce “thrashing” of the SD card. The problem is that flash memory segments wear out after a fairly low number of erase cycles, and the SD card’s wear-leveling algorithm will eventually cordon off enough of the card to cause file system issues. His “Log2Ram” is a simple Unix shell script that sets up a mount point for logging in RAM rather than on the SD card.

The idea is that any application or service sending log entries to /var/log will actually be writing them to virtual log files, which won’t rack up any activity on the SD card. Every hour, a cron job sweeps the virtual logs out to the SD card, greatly reducing its wear. There’s still a chance to lose logging data before it’s swept to disk, but if you have relatively stable system it’s a small price to pay for the long-term health of a Pi that’s out of sight and out of mind.

One thing we really like about [Erich]’s project is that it’s a great example of shell scripting and Linux admin concepts. If you need more information on such things, check out [Al Williams’] Linux-Fu series. It goes back quite a way, so settle in for some good binge reading.