Review: Hands On With The Swarm Satellite Network Eval Kit

If you have devices out in the field, you probably want to connect with them. There was a time when that was hard to do, requiring telephone wires or specialized radio gear. Now cellular data is prevalent, but even cellular isn’t everywhere. If you have the cash, you can pay a number of satellite companies to carry your data, but that’s generally pricey and has its own challenges.

The age of satellite constellations is changing that. Of course everyone by now has heard of Starlink which is offering satellite internet via numerous satellites that are much smaller than traditional telecom satellites. But they’re not the only came in town.

A company called Swarm has put up a constellation of 1/4U cube satellites in low orbits. They offer a ground station that uses an omni antenna and a subscription access program for small amounts of data. They sent us a unit to review, and while I haven’t used the system in a real project yet, the kit was pretty impressive.

About Swarm

Swarm tile device
The Swarm Tile is made to mount on a PCB

The Swarm “tile” is a tiny radio that can talk bi-directionally with small satellites in low Earth orbit. The little unit is made to mount on a PCB, can control its power consumption, and talks to your system via a standard 3.3V UART connection. It does, however, require a small antenna and maybe even a smaller antenna for its GPS module. Small, in this case, is about a mid-size handy talkie antenna. There is a half-wave antenna that doesn’t need a ground plane and a shorter antenna that does need a ground plane.

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Scanning electron micrograph of a microfabricated lens array

Getting A Fly’s-Eye View With Microfabricated Lens Arrays

Atomic force microscopy, laser ablation, and etching with a witches brew of toxic chemicals: sounds like [Zachary Tong] has been playing in the lab again, and this time he found a way to fabricate arrays of microscopic lenses as a result.

Like many of the best projects, [Zach]’s journey into micro-fabrication started with a happy accident. It happened while he was working on metal-activated chemical etching (MACE), which uses a noble metal catalyst to selectively carve high-aspect-ratio features in silicon. After blasting at a silver-coated silicon wafer with a laser, he noticed the ablation pits were very smooth and uniform after etching. This led him to several hypotheses about what was going on, all of which he was able to test.

The experiments themselves are pretty interesting, but what’s really cool is that [Zach] realized the smooth hemispherical pits in the silicon could act as a mold for an array of microscopic convex lenses. He was able to deposit a small amount of clear silicone resin into the mold by spin-coating, and (eventually) transfer the microlens array to a glass slide. The lenses are impressively small — hundreds of them over only a couple hundred square microns — and pretty well-formed. There’s always room for improvement, of course, but for an initial attempt based on a serendipitous finding, we’d call it a win. As for what good these lenses are, your guess is as good as ours. But novel processes like these tend to find a way to be useful, and the fact that this is coming out of a home lab doesn’t change that fact.

We find this kind of micro-fabrication fascinating. Whether it’s making OLED displays, micro-machining glass with plasma, or even rolling your own semiconductors, we can’t get enough of this stuff.

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Pandemic Gives Passersby A Window On Cyborg Control

What’s this? Another fabulous creation from [Niklas Roy] and [Kati Hyyppä] that combines art and electronics with our zeitgeist and a lot of recycled bits and bobs? You got it. Their workshop in eastern Berlin used to be a retail shop and has a large display window as a result. This seems perfect for a pair of artists in a pandemic, because they can communicate with the community through the things they display in the window. Most recently, it was this interactive cyborg baby we are choosing to call Cybaby.

You might recognize Cybaby as one of the very hackable Robosapien robots, but with a baby doll head. (It also has a single red eye that really pulls its look together.) In the window, Cybaby comes alive and toddles around against a backdrop that grew and evolved over several weeks this spring and summer. Passersby were able to join the network and control Cybaby from outside with their smartphone to make it walk around, press various buttons that change its environment, and trigger a few sensors here and there. Robosapien has been around for about 20 years, so there is already Arduino code out there that essentially simulates its R/C signals. [Niklas] and [Kati] used a NodeMCU (ESP12-E) to send pulses to the IR input of the robot.

Back on the zany zeitgeist front, there’s a hair salon, a convenience store, and a nightclub for dancing that requires a successful trip through the testing center first (naturally). Oh, and there’s a lab next door to the nightclub that can’t be accessed by Cybaby no matter what it tries or how it cries. Check it out after the break.

There’s a dearth of Robosapien posts for some reason, so here’s what [Niklas] and [Kati] had in their window before the World of Cybaby — a really cool pen plotter that prints out messages sent by people walking by.

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Squares of sample materials placed on the laser bed awaiting the sensing head

Smart Laser Cutter Ad-on Detects Material Optically

Come on now, admit it. You’ve done it. We’ve done it. You know — you were really sure that sheet of plastic stock you found lying around the hackerspace was acrylic right? You dialled in the settings, loaded the design, set the focus and pushed the little green ‘start’ button. Lots of black smoke, fire, and general badness ensued as you lunged for the red ‘stop’ button, before lifting the lid to work out how you’re going to clean this one up.

That was not acrylic. That was polycarbonate.

What you need is the latest gadget from MIT: SensiCut: A smart laser cutter system that detects different materials automatically.

The technique makes use of so-called ‘speckle imaging’ where a material illuminated by a laser will produce a unique pattern of reflected spots, or speckles into a camera. By training a deep neural model with a large set of samples, it was found possible to detect up to 30 types of material with 98% accuracy.

The pre-baked model runs on a Raspberry PI zero with an off-the-shelf camera all powered from a power bank. This allows the whole assembly to simply drop onto an existing laser cutter head, with no wiring needed.

Even if you’re a seasoned laser cutter user, with a well-controlled stock pile, the peace-of-mind this could give would definitely be worth the effort. A more detailed description and more videos may be found by reading the full paper. Here’s hoping they release the system as open source, one day in the not-to-distant future. If not, then, you know what to do :)

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the introduction page of "a summary of electronics"

This Electronics Overview Guides New Hackers In The Right Direction

Many of us don’t have a formal background to build off when taking on new hacks, we have had to teach ourselves complex concepts and learn by doing (or more commonly, by failing). To help new hackers get off the ground a bit easier, [PhilosopherFar3847] created a fantastic starter’s resource on electronics, The Electroagenda Summary of Electronics.

[PhilosipherFar3847] created Electroagenda with the goal of helping amateurs, students, and professionals alike better understand electronics. The Summary of Electronics, one of the more recent additions to the website, is split across 26 sections each breaking down a different electrical concept into easy-to-understand facts with no math or unfamiliar jargon. The summary covers a broad range of electronics, from simple passive components and their uses, up to the basic operating concepts of a microcontroller.

While this resource on its own will not be enough to get a fledgling hacker started making cool circuits, it does provide a very important skill; knowing how to ask the right questions. This base of knowledge provides enough context and keywords to better articulate a challenge and Google-fu a bit more effectively.

Are you the aforementioned fledgling hacker, looking to learn more? check out these nifty logic gates you can plug into each other to build a basic circuit.

[via r/diyelectronics]

Homebrew Sounder Maps The Depths In Depth

For those who like to muck around in boats, there’s enough to worry about without wondering if you’re going to run aground. And there’s really no way to know that other than to work from charts that show you exactly what lies beneath. But what does one do for places where no such charts exist? Easy — make your own homebrew water depth logger.

Thankfully, gone are the days when an able seaman would manually deploy the sounding line and call out the depth to the bottom. [Neumi]’s sounding rig uses an off-the-shelf sonar depth sounder, one with NMEA, or National Marine Electronic Association, output. Combined with a GPS module and an Arduino with an SD card, the rig can keep track not only of how much water is below it, but exactly where the measurement point is. The whole thing is rigged up to an inflatable dinghy which lets it slowly ply the confines of a small marina, working in and out of the nooks and crannies. A bit of Python and matplotlib stitches that data together into a bathymetric map of the harbor, with pretty fine detail. The chart also takes the tides into account, as the water level varies quite a bit over the four hours it takes to gather all the data. See it in action in the video after the hop.

There’s something cool about revealing the mysteries of the deep, even if they’re not that deep. Want to go a little deeper? We’ve seen that before too.

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M4 Breadstick Is A Tasty Prototyping Alternative

What does “breadboard-friendly” mean to you? It’s become a game of minimum viability. Sure, it fits in the breadboard, but are there any accessible tie points left for wires and components? What good is a development board if you can’t easily prototype with it?

A few years ago, [Michael Rangen] set out to change all of that by creating a long and skinny development board that spaces out the I/O pins and simplifies wiring, making every circuit beautiful and easier to take in visually. The current version is an adaptation of Adafruit’s ItsyBitsy M4 Express. It has 20 I/O pins, all spread out along the length and numbered around the horn like an IC. [Michael] dipped this breadstick in 24 tiny RGB LEDs, all of which are on a dedicated com bus.

We think this is a great idea that will definitely make microcontrollers more hackable. This type of layout would make checking students’ work a breeze, and you can make tidy prototypes with it yourself after class. Today the board runs CircuitPython, and it will be able to run Arduino in the future.

This ESP socket may not leave quite as many tie points open, but it’s way easier than soldering header to it.