Digital Video From The Amiga’s DB23 Socket

February 19, 2023 by Jenny List 5 Comments

Back in the days of 16-bit home computers, the one to have if your interests extended to graphics was the Commodore Amiga. It had high resolutions for the time in an impressive number of colours, and thanks to its unique video circuitry, it could produce genlocked broadcast-quality video. Here in 2023 though, it’s all a little analogue. What’s needed is digital video, and in that, [c0pperdragon] has our backs with the latest in a line of Amiga video hacks. This one takes the 12-bit parallel digital colour that would normally go to the Amiga’s DAC, and brings it out into the world through rarely-used pins on the 23-pin video connector.

This follows on from a previous [c0pperdragon] project in which a Raspberry Pi Zero was used to transform the digital video into HDMI. This isn’t a hack for the faint-hearted though, as it involves extensive modification of your treasured Amiga board.

It is of course perfectly possible to generate HDMI from an Amiga by using an external converter box from the analogue video output, of the type which can be bought for a few dollars from online vendors. What this type of hack gives over the cheap approach is low latency, something highly prized by gamers. We’re not sure we’re ready to start hacking apart our Amigas, but we can see the appeal for some enthusiasts.

The USAF (Almost) Declares War On Illinois Radio Amateurs

February 18, 2023 by Jenny List 132 Comments

Every week the Hackaday editors gather online to discuss the tech stories of the moment, and among the topics this week was the balloons shot down over North America that are thought to be Chinese spying devices. Among the banter came the amusing thought that enterprising trolls on the Pacific rim could launch balloons to keep the fearless defenders of American skies firing off missiles into the beyond.

But humor may have overshadowed by events, because it seems one of the craft they shot down was just that. It wasn’t a troll though, the evidence points to an amateur radio pico balloon — a helium-filled Mylar party balloon with a tiny solar-powered WSPR transmitter as its payload.

The balloon thought to have been shot down was launched by the Northern Illinois Bottlecap Balloon Brigade, a group of radio amateurs who launch small helium-filled Mylar balloons carrying the barest minimum for a solar-powered WSPR beacon. Its callsign was K9YO, and having circumnavigated the globe seven times since its launch on the 10th of October it was last seen off Alaska on February 11th. Its projected course and timing tallies with the craft reported shot down by the US Air Force, so it seems the military used hundreds of thousands of dollars-worth of high-tech weaponry to shoot down a few tens of dollars worth of hobby electronics they could have readily tracked online. We love the smell of napalm in the morning!

Their website has a host of technical information on the balloons and the beacons, providing a fascinating insight into this facet of amateur radio that is well worth a read in itself. The full technical details of the USAF missile system used to shoot them down, sadly remains classified.

Anatomy Of A Fake CO2 Sensor

February 18, 2023 by Jenny List 47 Comments

The pandemic brought with it a need to maintain adequate ventilation in enclosed spaces, and thus, there’s been considerable interest in inexpensive C02 monitors. Unfortunately, there are unscrupulous actors out there that have seen this as a chance to make a quick profit.

Recently [bigclivedotcom] got one such low-cost CO2 sensor on his bench for a teardown, and confirms that it’s a fake. But in doing so he reveals a fascinating story of design decisions good and bad, from something which could almost have been a useful product.

Behind the slick color display is a PCB with an unidentified microcontroller, power supply circuitry, a DHT11 environmental sensor, and a further small module which purports to be the CO2 sensor. He quickly demonstrates with a SodaStream that it doesn’t respond to CO2 at all, and through further tests is able to identify it as an alcohol sensor.

Beyond the alcohol sensor he analyses the PSU circuitry. It has a place for a battery protection chip but it’s not fitted, and an error in the regulator circuitry leads to a slow drain of the unprotected cell. Most oddly there’s an entire 5 volt switching regulator circuit that’s fitted but unused, being in place to support a missing infra-red module. Finally the screen is an application-specific LCD part.

It’s clear some effort went in to the design of this unit, and we can’t help wondering whether it could have started life as a design for a higher-spec genuine unit. But as [Clive] says, it’s a party detector, and of little more use than as a project case and battery.

Need more dubious instrumentation? How about a magnetic field tester?

Continue reading “Anatomy Of A Fake CO2 Sensor” →

Virgin Orbit’s First UK Launch Attempt: What Went Wrong

February 15, 2023 by Jenny List 13 Comments

A month ago there was disappointment as Virgin Orbit’s first attempt at a space launch from the United Kingdom using its converted Boeing 747 airliner platform failed to achieve orbit. Now with the benefit of a lot of telemetry analysis the company have released their findings, which conclude that a fuel filter within the second stage became dislodged. The resulting fuel starvation was enough to cause the engine to receive insufficient cooling and overheat, bringing the mission to a premature end.

As we said at the time, the interesting part of the launch, midair from the 747, appears to have gone flawlessly. Space exploration is hard, and we are confident that they’ll fix any fuel filter mounting issues on future launches and be placing payloads in orbit for their customers soon afterwards. The whole program has seen significant news coverage in the UK where the craft has its base, and those of us in that environ will no doubt see it portrayed locally as a matter of national pride. The truth however will be that it flies on the talents of engineers from all corners of the world. We’ll be watching out next time, and look forward to a successful mission.

Header: Österreichisches Weltraum Forum, CC BY-SA 4.0.

What’s Old Is New Again: A Linux PC From A Set Top Box

February 15, 2023 by Jenny List 37 Comments

There was a time around two decades ago, when the new hotness was taking control of home routers to use as small Linux computers. An echo of this era lives on in the name of the OpenWrt minimal Linux distribution, in reference to the Linksys WRT54G router which started it all. Routers as small computers were displaced by small cheap Linux machines from the likes of Raspberry Pi, and the promise of discarded home network gear doing interesting stuff receded. Now it might just be back, as [Jasper Devreker] shows us an Android TV set-top box from a mobile carrier repurposed as a Linux computer that can even run a desktop environment.

The method starts as you might expect, by identifying a mystery connector as a debug serial port. This outputs all sorts of interesting boot information, but can be dropped into a uBoot shell. From here with a bit of effort the eMMC storage could be dumped, and from that the nature of the machine could be deduced. The CPU is an Amlogic quad core ARM Cortex-A53 SoC, which by a stroke of luck is a target for which an Armbian build is available. From there a Linux installation could be assembled, and even an AFCE desktop.

These boxes are handed out in the hundreds of thousands by home connectivity providers, so there’s value in this type of hack as they become available for experimenters. Perhaps it’s more useful as a small headless Linux machine than as a desktop, but we sense there are more machines to come in this line.

If you’d like a little bit of history on hackable Linux devices, have a read of one of our earliest posts featuring the Linksys WRT54G.

How Home Made Robot Arms Used To Be Made

February 14, 2023 by Jenny List 10 Comments

With laser cutters and 3D printers in our arsenal as well as the global toy shop of mass-produced parts and single-board computers, building a robotic project has almost never been easier. In times past though, there was more of a challenge, with a computer likely meaning a chunky desktop model and there being no plethora of motors at low prices, a robot arm required more ingenuity. [Marius Taciuc] shares with us an arm he built from the most minimal of parts back in 2003, and it’s a beautiful exercise in creative reuse.

The arm itself uses metal and FR4 for its structure, and borrows extensively from cassette tape mechanisms for motors and gears. The stronger motor for the forearm is a geared unit from a heating system, and to control all this, a relay board is hooked up to a computer’s parallel port. This last assembly is particularly ingenious, having no optocouplers handy he made his own by coupling LEDs to metal can transistors with their lids removed.

The arm was entered in a competition, and he relates a tale with which we’ll all be familiar — at the critical moment, it didn’t work. Fortunately a last-minute accidental covering of the board with a floppy disk solved the problem, as it turned out that enough light was leaking into those home-made optocouplers to trigger them. The prize was won not just on the strength of the arm, but on his explanation of the lessons learned along the way.

The once-ubiquitous parallel port is now absent from most computers, but there’s still plenty of scope for experimentation if you have one.

XML Is A Quarter Century Old

February 11, 2023 by Jenny List 58 Comments

For those of us who have spent entire careers working with structured data, it comes as something of a surprise to be reminded that XML is now 25 years old. You probably missed the XML standard on the 10th of February 1998, but it’s almost certain that XML has touched your life in many ways even if you remain unaware of it.

The idea of one strictly compliant universal markup language to rule them all was extremely interesting in an era when the Internet was becoming the standard means to interchange information and when the walled gardens dating back to the mini- and mainframe era were being replaced with open standards-based interchange. In the electronic publishing industry, it allowed encyclopedia and dictionary-sized data sets to be defined to a standard format and easily exchanged. At a much smaller level, it promised a standard way to structure more mundane transactions. Acronyms and initialisms such as WAP, SOAP, and XHTML were designed to revolutionize the Web of the 21st century, but chances are that those are familiar only to the more grizzled developers.

In practice the one-size-fits-all approach of XML left it unwieldy, giving the likes of JSON and HTML4 the opening to be the standards we used. That’s not to say XML isn’t hiding in plain sight though, it’s the container for the SVG graphics format. Go on — tell us where else XML can be found, in the comments!

So, XML. When used to standardise large structured datasets it can sometimes be enough to bring the most hardened of developers to tears, but it remains far better than what went before. When hammered to fit into lightweight protocols though, it’s a pain in the backside and is best forgotten. It’s 25 years old, and here to stay!

Header: [Jh20], GFDL v1.2.