Satellite Snoopers Pick Up Surprising TV Broadcast

March 22, 2022 by Jenny List 25 Comments

While Internet based streaming services appear to be the future of television, there are still plenty of places where it comes into the home via a cable, satellite, or antenna connection. For most satellite transmissions this now means a digital multiplex carrying a host of channels from a geostationary satellite, for which a set-top box or other decoder is required. Imagine the surprise of satellite-watchers than when the Russian polar communications satellite Meridian 9 which has a highly elliptical orbit was seen transmitting old-style terrestrial analogue TV (ThreadReader Link). What on earth was happening?

How a Russian polar comms satellite picked up a TV station.

The TV signal in question comes from Turkmenistan, so were some homesick Turkmenistanis in an Antarctic base being treated to a taste of their country? The truth is far more interesting than that, because the signal in question comes from a terrestrial transmitter serving domestic TV viewers in Turkmenistan.

We’ve all heard of the idea that somehow every TV show ever transmitted is somewhere out there still traveling as radio waves across space, and while perhaps we can’t fly far enough out to check for 1960s Doctor Who episodes it’s true that the horizontal transmissions from a TV tower pass out into space as the earth curves away from them.

Thus Meridian 9 passed through the beam from the Turkmenistan transmitter which happened to be on a UHF frequency that matched one of its transponders, and the result was an unexpected bit of satellite TV. We’re indebted to the work of [@dereksgc] and [Scott Tilley] for bringing us this fascinating observation. We’ve featured [Scott]’s work before, most notably when he relocated a lost NASA craft.

Hacked GDB Dashboard Puts It All On Display

March 22, 2022 by Al Williams 20 Comments

Not everyone is a fan of GUI interfaces. But some tasks really lend themselves to something over a bare command line. Very few people enjoy old command line text editors like edlin or ed. Debugging is another task where showing source files and variables at all times makes sense. Of course, you don’t absolutely have to have a GUI per se. You can also use a Text User Interface (TUI). In fact, you can build gdb — the GNU Debugger — with a built-in TUI mode. Try adding –tui to your gdb command line and see what happens. There are also many GUI frontends for gdb, but [cyrus-and] has an easy way to get a very useful TUI-like interface to gdb that doesn’t require rebuilding gdb or even hacking its internals in any way.

The secret? The gdb program runs a .gdbinit file on startup. By using Python and some gdb commands, [cyrus-and] causes the debugger to have a nice dashboard interface for your debugging sessions. If you install a helper script, you can even get syntax highlighting.

The system uses modules and you can even add your own custom modules and commands, if you like. You can also control what modules appear on each dashboard display. Normally, the dashboard shows when the program stops. For example, on each breakpoint. However, gdb has a hook system that allows you to trigger a dashboard using the appropriately-named dashboard command on other commands, too. Using the layout option to the dashboard command, you can even trigger different modules at different times.

Installation is simple. Just put the .gdbinit file in your home directory. If you want syntax highlights, you need to install Pygments, too. We understand you can even use his under Windows, if you like.

We don’t always take full advantage, but gdb is actually amazing. The flexible architecture makes all sorts of interesting things possible.

IR Remote Transforms To RF

March 21, 2022 by Al Williams 13 Comments

Most consumer remote controls operate using infrared light. This works well assuming the piece of equipment has a line of sight to the remote. But if you have, say a receiver in a cabinet or closet, the IR remote signal can’t reach the sensor. Some equipment has remote receivers that you can leave poking out, but it is still not very handy. That’s why some equipment now uses RF remotes. [Xtropie] used a pair of inexpensive 433 MHz RF modules to convert an IR system to RF. You can see a short video about the project below.

We might have been tempted to simply put an IR LED on the receiver so it could feed IR into the device sensor, but [Xtropie] took a different approach. He found the IR sensor and tied the RF receiver directly into its output. It seems to work, but we probably would have removed the IR sensor to make sure there were no conflicts.

Continue reading “IR Remote Transforms To RF” →

Web Serial Terminal Means It’s Always Hacking Time

March 21, 2022 by Tom Nardi 66 Comments

Arguably one of the most important pieces of software to have in your hardware hacking arsenal is a nice serial terminal emulator. There’s plenty of choice out there, from classic command line tools to flashier graphical options, which ultimately all do the same thing in the end: let you easily communicate with gadgets using UART. But now you’ve got a new choice — instead of installing a serial terminal emulator, you can simply point your browser to the aptly-named serialterminal.com.

Well, maybe. As of this writing it only works on Chrome/Chromium (and by extension, Microsoft Edge), so Firefox fans will be left out in the cold unless Mozilla changes their stance on the whole Web Serial API concept. But assuming you are running the appropriate browser, you’ll be able to connect with your serial gadgets with a simple interface that should be familiar to anyone who’s worked with more traditional terminal software. In a quick test here at the Hackaday Command Center, we were able to bring up the Bus Pirate UI with no problems using Chrome on Linux. Continue reading “Web Serial Terminal Means It’s Always Hacking Time” →

Your Vacuum Cleaner Follows You

March 21, 2022 by Al Williams 9 Comments

There are several projects you can imagine where it would be useful to have a robot follow you. For example, we’ve always wanted luggage that would trail us at the airport and we’ve seen several coolers that will follow you. [Madmax95] apparently dream of having a medical cart following a patient, though, and that’s good too. But how do you do it? [Max’s] method was to strip down a Roomba and build a work table and electronics on it. An Arduino controls the motor and communicates with a PC. The PC reads video from a Kinect camera on the robot and uses special tracking software to follow the patient.

We could easily imagine all of this project except the tracking. That depended on a service called Nuitrack. There is a free version that only works for 3 minutes, but it costs if you want to use it practically. However, it would still be cheaper than rolling your own if your time has value.

Continue reading “Your Vacuum Cleaner Follows You” →

Home Made Scanning Electron Microscope Shows Some Potential

March 21, 2022 by Dave Rowntree 7 Comments

Scanning electron microscopes are one of those niche instruments that most of us don’t really need all the time, but would still love to have access to once in a while. Although we’ve covered a few attempts at home-builds before, many have faltered, except this project over on Hackday.IO by user Vini’s Lab, which appears to be still under active development. The principle of the SEM is pretty simple; a specially prepared sample is bombarded with a focussed beam of electrons, that is steered in a raster pattern. A signal is acquired, using one of a number of techniques, such as secondary electrons (SE) back-scattered electrons (BSE) or simply the transmitted current into the sample. This signal can then be used to form an image of the sample or gather other properties.

The project is clearly in the early stages, as the author says, it’s a very costly thing to build, but already some of the machined parts are ready for assembly. Work has started on the drive electronics for the condenser stigmator. This part of the instrument takes the central part of the rapidly diverging raw electron beam that makes it through the anode, and with a couple of sets of octopole coil sets, and an aperture or two, selects only the central portion of the beam, as well as correcting for any astigmatism in the beam. By adjusting the relative currents through each of the coils, a quadrupole magnetic field is created, which counteracts the beam asymmetry.

Scanning control and signal acquisition are handled by a single dedicated card, which utilises the PIO function of a Raspberry Pi Pico module. The Pico can drive the scanning operation, and with an external FTDI USB3.0 device, send four synchronised channels of acquired sample data back to the host computer. Using PCIe connectors and mating edge connectors on the cards, gives a robust and cost effective physical connection. As can be seen from the project page, a lot of mechanical design is complete, and machining has started, so this is a project to keep an eye on in the coming months, and possibly years!

We have seen a few SEM hacks, here’s a teensy powered SEM hack from [Ben Krasnow] and here’s another attempt. For such a conceptually simple device, with such immense usefulness, its does seem a bit remiss that there aren’t more such projects out there.

A Macintosh-inspired desk ornament, next to a sceenshot of a classic Macintosh computer desktop

‘Desk Accessory’ Pays Homage To Macintosh

March 21, 2022 by Chris Wilkinson 9 Comments

The retrocomputing community are experts at keeping vintage Apple iron running, but if you’re looking for a simpler way to pay homage to the original Mac, check out this Raspberry Pi powered ‘desk accessory’ by [John Calhoun], fittingly called ‘SystemSix’.

Housed inside a delightfully Mac-shaped piece of laser-cut acrylic, SystemSix is powered by as Raspberry Pi 3, with the graphics displayed on a sizeable 5.83″ e-ink panel. While it resembles a kind of retro-futuristic take on the ‘classic’ Macintosh, SystemSix is the illusion of a fully interactive computer. While non-interactive, the fake desktop is every bit as charming as a real Macintosh display, albeit scaled down. The desktop updates automatically with new information, and presently includes a calendar, dithered lunar phase graphic, and a local weather report.

Clearly calling it a ‘desk accessory’ is a neat play on words. The original Macintosh implemented simple desk accessory programs, such as the calculator and alarm clock, that could run alongside the main application in memory. This was the only way to run more than one application on the Macintosh, before MultiFinder added rudimentary cooperative multitasking in 1987. As such, SystemSix is a functional, stylish and quite literal ‘desk accessory’.

[John] has the full project write-up over on GitHub, and goes into great detail about maintaining the Macintosh aesthetic. For example, the lunar phase graphic uses ‘Atkinson’ dithering. This technique was pioneered by Apple programmer Bill Atkinson, the author of MacPaint and the QuickDraw toolbox on the original Macintosh (and later, Hypercard).

And in case you were wondering – yes, this is the [John Calhoun], who programmed Glider for Macintosh. Now recently retired from Apple, we’re really excited to see what other Macintosh-inspired creations he comes up with. Maybe he will come back around to his Mac-powered MAME cabinets that we covered all the way back in 2005. Or perhaps a sleeper battlestation, like the iMac G4 lampshade that was upgraded with an M1 processor.