Ask Hackaday: What’s in Your Digital Bugout Bag?

Your eyes pop open in the middle of the night, darting around the darkened bedroom as you wonder why you woke up. Had you heard something? Or was that a dream? The matter is settled with loud pounding on the front door. Heart racing as you see blue and red lights playing through the window, you open the door to see a grim-faced police officer standing there. “There’s been a hazardous materials accident on the highway,” he intones. “We need to completely evacuate this neighborhood. Gather what you need and be ready to leave in 15 minutes.”

Most people will live their entire lives without a scenario like this playing out, but such things happen all the time. Whether the disaster du jour is man-made or natural, the potential to need to leave in a big hurry is very real, and it pays to equip yourself to survive such an ordeal. The primary tool for this is the so-called “bugout bag,” a small backpack for each family member that contains the essentials — clothing, food, medications — to survive for 72 hours away from home.

A bugout bag can turn a forced evacuation from a personal emergency into a minor inconvenience, as those at greatest risk well know — looking at you, Tornado Alley. But in our connected world, perhaps it pays to consider updating the bugout bag to include the essentials of our online lives, those cyber-needs that we’d be hard-pressed to live without for very long. What would a digital bugout bag look like?

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Ask Hackaday: Preserving Electronic Devices

Conventional wisdom holds that we no longer make things to last for the long haul, and that we live in a disposable world. It’s understandable — after all, most of us have a cell phone in our pocket that’s no more than a year or two old, and it’s often cheaper to buy a new printer than replace the ink cartridges. But most of that disposability is driven by market forces, like new software that makes a device obsolete long before it breaks down, or the razor and blades model that makes you pay through the nose for ink. It turns out that most electronic devices are actually pretty well engineered, and as long as they’re not abused can still be operating decades down the road.

But what happens when you want to put an electromechanical device away and preserve it for a rainy day? What can you do to make sure the device will operate again a few years down the road? Are there steps one can take beyond the typical “keep it in a cool, dry place” advice? In short, how do you preserve electronic devices?

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Ask Hackaday: How Small is Your Shop?

Electronics, metalwork, carpentry, sewing — however you express your inner hacker, you’ve got to have a place to work. Most of us start out small, assembling projects on the kitchen table, or sharing space on a computer desk. But eventually, if we’re lucky, we all move on to some kind of dedicated space. My first “shop” was a corner of the basement my Dad used for his carpentry projects. He built me what seemed at the time like a huge bench but was probably only about five feet long. Small was fine with me, though, and on that bench I plotted and planned and drew schematics and had my first real lesson in why you don’t reach for a soldering iron without looking first. My thumb still bears that scar as a reminder.

Many of us outgrow that first tiny space eventually, as projects (and accumulated junk) outpace the available space. Some of us go on to build workspaces to die for; personally, I feel wholly inadequate whenever I see Frank Howarth’s immense wood shop, with its high ceilings, huge windows for natural light, and what amounts to a loading dock. Whenever I see it I think The work I could do in there!

Or could I? Is bigger necessarily better when it comes to workspaces? Would more space make me a better craftsman?

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Ask Hackaday: SawStop — Bastion of Safety or Patent Troll

At first glance, SawStop seems like a hacker’s dream. A garage tinkerer comes up with a great idea, builds a product around it, and the world becomes a better place. As time has gone on, other companies have introduced similar products. Recently, SawStop successfully stopped Bosch from importing saws equipped with their Reaxx safety system into the USA. This not only impacts sales of new saws, but parts for existing equipment. Who gets screwed here? Unfortunately, it’s the owners of the Bosch saws, who now have a safety feature they might not be able to use in the future. This has earned some bad press for SawStop in forums and on websites like Reddit, where users have gone as far as to call SawStop a patent troll. Is that true or just Internet puffery? Read on and decide for yourself.

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Ask Hackaday: How Does This Air Particle Sensor Work?

The hardware coming out of [Dr. Peter Jansen]’s lab is the craziest stuff you can imagine. He’s built a CT scanner out of plywood, and an MRI machine out of many, many turns of enamel wire. Perhaps his best-known build is his Tricorder – a real, all-sensing device with permission from the estate of [Gene Roddenberry] to use the name. [Peter]’s tricorder was one of the finalists for the first Hackaday Prize, but that doesn’t mean he’s stopped working on it. Sensors are always getting better, and by sometime in the 23rd century, he’ll be able to fit a neutrino detector inside a tiny hand-held device.

One of the new sensors [Peter] is working with is the MAX30105 air particle sensor. The marketing materials for this chip say it’s designed for smoke detectors and fire alarms, but this is really one of the smallest dust and particle sensors on the market. If you want a handheld device that detects dust, this should be the chip you’re looking at.

Unfortunately, Maxim is being very, very tight-lipped about how this particle sensor works. There is a way to get access to raw particle counts and the underlying algorithms, and Maxim is more than willing to sell those algorithms through a third-party distributor. That’s simply not how we do things around here, so [Peter] is looking for someone with a fancy particle sensor to collect a few hours of data so he can build a driver for this chip.

Here’s what we know about the MAX30105 air particle sensor. There are three LEDs inside this chip (red, IR, and green), and an optical sensor underneath a piece of glass. The chip drives the LEDs, light reflects off smoke particles, and enters the optical sensor. From there, magic algorithms turn this into a number corresponding to a particle count. [Peter]’s hackaday.io log for this project has tons of data, math, and statistics on the data that comes out of this sensor. He’s also built a test rig to compare this sensor with other particle sensors (the DSM501A and Sharp sensors). The data from the Maxim sensor looks good, but it’s not good enough for a Tricorder. This is where you, o reader of Hackaday, come in.

[Peter] is looking for someone with access to a fancy particle sensor to collect a few hours worth of data with this Maxim sensor in a test rig. Once that’s done, a few statistical tests should be enough to verify the work done so far and build a driver for this sensor. Then, [Peter] will be able to play around with this sensor and hopefully make a very cheap but very accurate air particle sensor that should be hanging on the wall of your shop.

Ask Hackaday: Frequency Hopping on the nRF24l01+?

We’ve seen a lot of hacks with the nRF24l01+ 2.4 GHz radio modules. The tiny chips pack a lot of bang for the buck. Since the radios can switch frequencies relatively quickly, [Shubham Paul] decided to take advantage of this feature to make a rudimentary frequency-hopping communications channel.

The code is actually incredibly simple. Both the transmitter and receiver simply scan up and down over the defined channels. Because the clock speeds of any given pair of Arduinos are likely to be slightly different, it’s not a surprise that the radios eventually drift out of sync. Right now, as a quickie solution, [Shubham] is using a serial-port resynchronization: both are connected to the same computer, and he just tells them to get on the same channel. That’s not a horribly satisfying workaround. (But it’s a great start!)

Keeping two radios that are continually swapping channels in sync is no easy task, but it could possibly be made easier by taking advantage of the nRF’s acknowledge mode. If the delay between a sent acknowledge message and a received one were constant, these events (one on TX and one on RX) could be used to re-sync the two hopping cycles. All of this would probably require more temporal resolution than you’re going to get out of a microprocessor running Arduino code, but should be possible using hardware timers. But this is pure speculation. We briefly looked around and couldn’t find any working demos.

So Hackaday, how would you remotely sync two nRF24s on the cheap? Or is this a crazy idea? It might help to make transmissions more reliable in the face of 2.4 GHz band interference. Has anyone implemented their own frequency hopping scheme for the nRF24l01+?

Ask Hackaday: Helping Hands

[ProtoG] sent us in this video (also below) where he demonstrates the use of machinist’s dial-gauge indicator arms as helping hands. I’ll admit that I got so jealous that I ordered a pair. I wouldn’t say that I need more tools to hold things in place, but I certainly want them. The rapid coarse placement combined with fine adjustment looks so sweet. Using them as scope-probe holders is brilliant.

Our own helping hands, purchased for $5 from a surplus shop, have seen nearly twenty years of use now. About ten years ago, I heat-shrinked and plasti-dipped the jaws, and since then they do less damage to cable insulation. The clips kept coming loose, but that was fixed with a little epoxy. I never used the magnifying glass, and by removing it I bought some more sliding room for the jaws, which was an easy win. The base has a “non-slip” coating of Shoe-Goo that keeps it in place on the desk. Cork might be classier.

For bigger holding, there’s always the desk vise, though I’ll admit that I mostly use it for holding PCBs while soldering, and that a better solution for that particular task wouldn’t hurt. [Mike Szczys] tells me that the Stickvise seen here is a handy thing to have on the bench. It started on Hackaday.io and we still carry it in the store.

For grabbing the fiddly little things, nothing beats a pair of hemostats and a range of tweezers. Hemostats in the desk vise make a great ad hoc holder. Good sharp tweezers pay for themselves with the first removed splinter, or placing SMT parts.

So, Hackaday, what do you use for holding things? What do you hold your PCBs with while soldering? What do you use to hold down SMD parts? What’s your third hand, or twenty-third? Continue reading “Ask Hackaday: Helping Hands”