Hackaday Links: October 11, 2020

If you’re interested in SDR and digital signal processing but don’t know where to start, you’re in luck. Ben Hillburn, president of the GNU Radio Project, recently tweeted about an online curriculum for learning SDR and DSP using Python. The course was developed by Dr. Mark Lichtman, who was a lead on GNU Radio, and from the look of it, this is the place to go to learn about putting SDRs to use doing cool things. The course is chock full of animations that make the concepts clear, and explain what all the equations mean in a way that’s sure to appeal to practical learners.

It’s not much of a secret that the Hackaday community loves clocks. We build clocks out of everything and anything, and any unique way of telling time is rightly applauded and celebrated on our pages. But does the clock motif make a good basis for a video game? Perhaps not, but that didn’t stop Clock Simulator from becoming a thing. To “play” Clock Simulator, you advance the hands of an on-screen clock by pressing a button once per second. Now, thanks to Michael Dwyer, you don’t even have to do that one simple thing. He developed a hardware cheat for Clock Simulator that takes the 1PPS output from a GPS module and wires it into a mouse. The pulse stream clicks the mouse once per second with atomic precision, rendering the player irrelevant and making the whole thing even more pointless. Or perhaps that is the point.

Maybe we were a little hard on Clock Simulator, though — we can see how it would help achieve a Zen-like state with its requirement for steady rhythm, at least when not cheating. Another source of Zen for some is watching precision machining, and more precise, the better. We ran into this mesmerizing video of a CNC micro-coil winder and found it fascinating to watch, despite the vertical format. The winder is built from a CNC lathe, to the carriage of which a wire dispenser and tensioning attachment have been added. The wire is hair-fine and passes through a ruby nozzle with a 0.6 mm bore, and LinuxCNC controls the tiny back and forth motion of the wire as it winds onto the form. We don’t know what the coil will be used for, but we respect the precision of winding something smaller than a matchhead.

Dave Jones over at EEVblog posted a teardown video this week that goes to a place few of us have ever seen: inside a processor module for an IBM System/390 server. These servers earned the name “Big Iron” for a reason, as everything about them was engineered to perform. The processor module Dave found in his mailbag was worth $250,000 in 1991, and from the look of it was worth every penny. From the 64-layer ceramic substrate supporting up to 121 individual dies to the stout oil-filled aluminum enclosure, everything about this module is impressive. We were particularly intrigued by the spring-loaded copper pistons used to transfer heat away from each die; the 2,772 pins on the other side were pretty neat too.

Here’s an interesting question: what happens if an earthquake occurs in the middle of a 3D printing run? It’s probably not something you’ve given much thought, but it’s something that regular reader Marius Taciuc experienced recently. As he relates, the magnitude 6.7 quake that struck near Kainatu in Papua New Guinea (later adjusted to a 6.3 magnitude) resulted in a solid 15 seconds of shaking at his location, where he was printing a part on his modified Mendel/Prusa i2. The shaking showed up clearly in the part as the machine started swaying with the room. It’s probably not a practical way to make a seismograph, but it’s still an interesting artifact.

An Elegant Modular Enclosure System For The Raspberry Pi 4

[NODE] has been experimenting with Raspberry Pi servers and mini computers for a long time, and knows all too well how the wiring can quickly turn into a rat’s nest. His latest creation is  the Mini Server version 3, a modular enclosure system for the Raspberry Pi 4, is designed to turn it into practical computing box.

The basic enclosure is a 92 mm x 92 mm x 26 mm 3D printed frame with a custom PCB top cover. One of the main goals was to collect all the major connectors on one side and make the micro SD slot easily accessible. To do this [NODE] created a set of custom PCB adaptors to route the USB-C and an HDMI port to the same side as the other USB ports, and move the micro SD slot to the bottom of the enclosure. A low profile adaptor was also designed to connect a mSATA SSD to one of the USB 3 ports, and there is space inside the enclosure for one or two cooling fans. Unlike previous version of the mini server, no hardware modifications are required on the Pi itself.

The only downside that we can see is that it doesn’t allow external access to the GPIO ports, but the entire project is open source specifically to allow people to make their own modifications.

[NODE] is a big fan of turning Raspberry Pis into custom computing devices, ranging from small terminal devices and pocket servers, to complete laptops.

Displaying Incoming Server Attacks By Giving Server Logs A Scoreboard

In the server world, it’s a foregone conclusion that ports shouldn’t be exposed to the greater Internet if they don’t need to be. There are malicious bots everywhere that will try and randomly access anything connected to a network, and it’s best just to shut them off completely. If you have to have a port open, like 22 for SSH, it’ll need to be secured properly and monitored so that the administrator can keep track of it. Usually this is done in a system log and put to the side, but [Nick] wanted a more up-front reminder of just how many attempts were being made to log into his systems.

This build actively monitors attempts to log into his server on port 22 and notifies him via a numerical display and series of LEDs. It’s based on a Raspberry Pi Zero W housed in a 3D-printed case, and works by interfacing with a program called fail2ban running on the server. fail2ban‘s primary job is to block IP addresses that fail a certain number of login attempts on a server, but being FOSS it can be modified for situations like this. With some Python code running on the Pi, it is able to gather data fed to it from fail2ban and display it.

[Nick] was able to see immediate results too. Within 24 hours he saw 1633 login attempts on a server with normal login enabled, which was promptly shown on the display. A video of the counter in action is linked below. You don’t always need a secondary display if you need real-time information on your server, though. This Pi server has its own display built right in to its case.

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Ubuntu Update Hack Chat

Join us on Wednesday, July 22 at noon Pacific for the Ubuntu Update Hack Chat with Rhys Davies and Alan Pope!

Everyone has their favorite brands, covering everything from the clothes they wear to the cars they drive. We see brand loyalty informing all sorts of acquisition decisions, not only in regular consumer life but in technology, too. Brand decisions sort people into broad categories like Mac versus PC, or iPhone versus Android, and can result in spirited discussions of the relative merits of one choice over the others. It’s generally well-intentioned, even if it gets a bit personal sometimes.

Perhaps no choice is more personal in hacker circles than which Linux distribution to use. There are tons to choose from, each with their various features and particular pros and cons. Ubuntu has become a very popular choice for Linux aficionados, attracting more than a third of the market. Canonical is the company behind the Debian-based distro, providing editions that run on the desktop, on servers, and on a variety of IoT devices, as well as support and services for large-scale users.

To fill us in on what’s new in the world of Ubuntu, Canonical product manager Rhys Davies and developer advocate Alan Pope will stop by the Hack Chat this week. They’ll be ready to answer all your questions about the interesting stuff that’s going on with Ubuntu, including the recently announced Ubuntu Appliances, easy to install, low maintenance images for Raspberry Pis and PCs that are built for security and simplicity. We’ll also talk about snaps, desktops, and whatever else crops up.

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, July 22 at 12:00 PM Pacific time. If time zones have 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. Continue reading “Ubuntu Update Hack Chat”

Possible Spyware On Samsung Phones

[Editor’s note: There’s an ongoing back-and-forth about this “spyware” right now. We haven’t personally looked into it on any phones, and decoded Wireshark caps of what the cleaner software sends home seem to be lacking — it could be innocuous. We’re leaving our original text as-run below, but you might want to take this with a grain of salt until further evidence comes out. Or keep us all up to date in the comments. But be wary of jumping to quick conclusions.]

Samsung may have the highest-end options for hardware if you want an Android smartphone, but that hasn’t stopped them from making some questionable decisions on the software they sometimes load on it. Often these phones come with “default” apps that can’t be removed through ordinary means, or can’t even be disabled, and the latest discovery related to pre-loaded software on Samsung phones seems to be of a pretty major security vulnerability.

This software in question is a “storage cleaner” in the “Device Care” section of the phone, which is supposed to handle file optimization and deletion. This particular application is made by a Chinese company called Qihoo 360 and can’t be removed from the phone without using ADB or having root. The company is known for exceptionally bad practices concerning virus scanning, and the software has been accused of sending all information about files on the phone to servers in China, which could then turn all of the data it has over to the Chinese government. This was all discovered through the use of packet capture and osint, which are discussed in the post.

These revelations came about recently on Reddit from [kchaxcer] who made the original claims. It seems to be fairly legitimate at this point as well, and another user named [GeorgePB] was able to provide a temporary solution/workaround in the comments on the original post. It’s an interesting problem that probably shouldn’t exist on any phone, let alone a flagship phone competing with various iPhones, but it does highlight some security concerns we should all have with our daily use devices when we can’t control the software on the hardware that we supposedly own. There are some alternatives though if you are interested in open-source phones.

Thanks to [kickaxe] for the tip!

Photo from Pang Kakit [CC BY-SA 3.0 DE (https://creativecommons.org/licenses/by-sa/3.0/de/deed.en)]

Laptop Like It’s 1979 With A 16-Core Z80 On An FPGA

When life hands you a ridiculously expensive and massively powerful FPGA dev board, your first reaction may not be to build a 16-core Z80 laptop with it. If it’s not, perhaps you should examine your priorities, because that’s what [Chris Fenton] did, with the result being the wonderfully impractical “ZedRipper.”

Our first impression is that we’ve got to start hanging around a better class of lab, because [Chris] came by this $6000 FPGA board as the result of a lab cleanout; the best we ever scored was a few old Cat-5 cables and some power strips. The Stratix FPGA formed the heart of the design, surrounded by a few breakout boards for the 10.1″ VGA display and the keyboard, which was salvaged from an old PS/2. The 16 Z80 cores running in the FPGA are connected by a ring-topology network, which [Chris] dubs the “Z-Ring”. One of the Z80 cores, the server core, runs CP/M 2.2 and a file server called CP/NET, while the other fifteen machines are clients that run CP/NOS. A simple window manager shows 80 x 25 character terminal sessions for the server and any three of the clients at once, and the whole thing, including a LiPo battery pack, fits into a laser-cut plywood case. It’s retro, it’s modern, it’s overkill, and we absolutely love it.

Reading over [Chris]’s build log puts us in the mood to break out our 2019 Superconference badge and try spinning up a Z80 of our own. If you decide to hack the FPGA-est of conference badges, you might want to check out what [Sprite_TM] has to say about it. After all, he designed it. And you’ll certainly want to look at some of the awesome badge hacks we saw at Supercon.

Thanks to [yNos] for the tip.

Raspberry Pi NAS Makes Itself At Home In Donor PC

It’s safe to say that most of us have at least one Raspberry Pi hanging from a USB cable someplace, silently hammering away at some unglamorous task that you’d rather not do on a “real” computer. With as cheap as they are, it’s not like there’s a big concern about where it sets up shop. But if you’re like [Jeremy S. Cook] and want your $35 Linux computer to be a permanent member of the family, then his tips on turning an old PC into a gloriously overkill Pi NAS may be of interest.

The main component [Jeremy] salvages from the old Lenovo desktop PC is, obviously, the case itself. Stripped of its original components, the case gives him plenty of room to mount the Pi as well as a couple of hard drives and a powered USB hub. To prevent the bottom of the Raspberry Pi from shorting out against the metal computer case, he designed and 3D printed a mount for it. Everything else is held down with hook and loop fastener, making it quick and easy to move things around and make adjustments.

While it might not be strictly necessary, [Jeremy] also took the time to salvage the computer’s old heatsink. Being far too large to fit on the Pi as-is, he ran a line down the back of it with his mill and snapped it in half. He uses a bit of thermal tape to hold the bisected heatsink onto the Pi’s SoC, with a couple pieces of electrical tape to make sure it doesn’t short out on anything.

Raspberry Pi NAS builds are exceptionally popular, and we’ve seen more than we can count over the years. You can build one out of parts from IKEA, and if you don’t mind plastic, you can always 3D print the whole thing. If you really want to go minimal, you can even hang some files on the network with little more than a Pi Zero stuck into a USB port.

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