A business card-sized synthesizer with capacitive touch pads.

2024 Business Card Challenge: The Gift Of Music

Has anyone ever told you that you just can’t carry a tune? If you were to be the lucky recipient of one of [Ayu]’s synthesizer business cards, well, then it really couldn’t be helped.

This tiny, go-anywhere instrument has quite a lot going for it. It’s easy for anyone to pick up and play something, but versatile enough that a more experienced musician can add complexity. While we do tend to see twelve keys in a small form-factor like this, the Canta-Cart uses them a bit differently. Only ten are tied to notes, and the other two are for transposition.

[Ayu] was able to keep the BOM cost way down by using the PY32, which is an ARM Cortex-M microcontroller made by Puya that costs as little as 10¢ each. In fact, the whole BOM clocks in around 60¢ total even with the audio DAC and amplifier ICs, which really makes these ideal to actually give away to people. Check it out in action after the break, or try it in the browser!

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You Can Build A Little Car That Goes Farther Than You Push It

Can you build a car that travels farther than you push it? [Tom Stanton] shows us that you can, using a capacitor and some nifty design tricks.

[Tom]’s video shows us the construction of a small 3D printed trike with a curious drivetrain. There’s a simple generator on board, which charges a capacitor when the trike is pushed along the ground. When the trike is let go, however, this generator instead acts as a motor, using energy stored in the capacitor to drive the trike further.

When put to the test by [Tom], both a freewheeling car and the capacitor car are pushed up to a set speed. But the capacitor car goes farther. The trick is simple – the capacitor car can go further because it has more energy. But how?

It’s all because more work is being done to push the capacitor car up to speed. It stores energy in the capacitor while it’s being accelerated by the human pushing it. In contrast, after being pushed, the freewheeling car merely coasts to a stop as it loses kinetic energy. However, the capacitor car has similar kinetic energy plus the energy stored in its capacitor, which it can use to run its motor.

It’s a neat exploration of some basic physics, and useful learning if you’ve ever wondered about the prospects of perpetual motion machines.

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Embedded Python: MicroPython Is Amazing

In case you haven’t heard, about a month ago MicroPython has celebrated its 11th birthday. I was lucky that I was able to start hacking with it soon after pyboards have shipped – the first tech talk I remember giving was about MicroPython, and that talk was how I got into the hackerspace I subsequently spent years in. Since then, MicroPython been a staple in my projects, workshops, and hacking forays.

If you’re friends with Python or you’re willing to learn, you might just enjoy it a lot too. What’s more, MicroPython is an invaluable addition to a hacker’s toolkit, and I’d like to show you why. Continue reading “Embedded Python: MicroPython Is Amazing”

Ticketmaster SafeTix Reverse-Engineered

Ticketmaster is having a rough time lately. Recently, a hacker named [Conduition] managed to reverse-engineer their new “safe” electronic ticket system. Of course, they also had the recent breach where more than half a billion accounts had personal and financial data leaked without any indication of whether or not the data was fully encrypted. But we’re going to focus on the former, as it’s more technically interesting.

Ticketmaster’s stated goals for the new SafeTix system — which requires the use of a smartphone app — was to reduce fraud and ticket scalping. Essentially, you purchase a ticket using their app, and some data is downloaded to your phone which generates a rotating barcode every 15 seconds. When [Conduition] arrived at the venue, cell and WiFi service was totally swamped by everyone trying to load their barcode tickets. After many worried minutes (and presumably a few choice words) [Conduition] managed to get a cell signal long enough to update the barcode, and was able to enter, albeit with a large contingent of similarly annoyed fans trying to enter with their legally purchased tickets.

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Celebrating The [Jack Ells] Automatic Photometric Telescope

Here at Hackaday, we take pride in presenting the freshest hacks and the best of what’s going on today in the world of hardware hacking. But sometimes, we stumble upon a hack from the past so compelling that we’ve got to bring it to you, so we can all marvel at what was possible in the Before Times.

This one, a completely homebrewed automatic photometric telescope, was designed and built by the father-son team of [Jack Ells] and [Peter Ells]. From the elder [Ells]’ field notes, the telescope saw its first light in 1988, giving us some idea of the scale of problems that had to be overcome to get this wonderful machine working. The optics are straightforward, as least as telescopes go — it’s an f-4.0 Newtonian reflector with an 8.5″ (221 mm) primary mirror on an equatorial mount. The telescope is very rugged-looking indeed, and even stands on brick piers for stability. The telescope’s mount is controlled by a BBC Micro running custom BASIC software.

For the photometric parts, the [Ells] boys installed a photo-multiplier tube at the focus of the telescope. More precisely, they used a liquid light guide to connect the eyepiece to a rack full of equipment, which included the PM tube, its high-voltage power supply, and a series of signal conditioners and counter circuits. The idea was to view a single star through a pinhole mask over the objective of the telescope and count the rate of photons received over time. Doing so would reveal periodic changes in the star’s brightness. Today we’d use similar data to search for exoplanet transits; while we don’t think that was a thing back in 1988, it looks like this telescope could easily have handled the job.

Sadly, [Jack Ells] died only two years after finishing the telescope. But he left it with his son, who eventually moved it to a location with better seeing conditions, where it gathered data for another eight years. The quality of the work is amazing, and as father-son projects go, this one is tough to beat.

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Giving The Original Xbox 256 MB Of Memory

The original Xbox forever changed the console world, because it was basically just PC components laced together in a slightly different architecture. It featured a Pentium 733 MHz CPU with just 64MB of RAM. [Prehistoricman] has been hard at work, figuring out how to up that to 256MB instead.

This isn’t [Prehistoricman’s] first rodeo. Previously, he managed to up the Xbox’s RAM to 128 MB. To figure out how to go further, he had to figure out the addressing scheme. A datasheet for the Xbox’s original memory chip was a help in this regard, as was the envytools project and an Xbox source code leak.

A BIOS hack was needed to move the auto-precharge pin to free up more address pins for the higher memory space. Furthermore, the only available memory chips that were suitable used BGA packages, so a small PCB with castellated edges was needed to adapt the chip to the Xbox’s motherboard, which expects a TQFP package.

Ultimately, getting this hack to work involved a lot of bare-metal hacking. It also won’t help the performance of commercial games at all, as they were all designed within the limitations of the original console. Still, it’s impressive to see this now-ancient platform hacked to do more. It’s also hilarious to compare it with a contemporary PC, which could simply accept 256 MB of RAM by using additional memory slots. Video after the break.

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Hacking Airline WiFi The Hard Way

We’ve all been there. You are on a flight, there’s WiFi, but you hate to pay the few bucks just to watch dog videos. What to do? Well, we would never suggest you engage in theft of service, but as an intellectual exercise, [Robert Heaton] had an interesting idea. Could the limited free use of the network be coopted to access the general internet? Turns out, the answer is yes.

Admittedly, it is a terrible connection. Here’s how it works. The airline lets you get to your frequent flier account. When there, you can change information such as your name. A machine on the ground can also see that change and make changes, too. That’s all it takes.

It works like a drop box. You take TCP traffic, encode it as fake information for the account and enter it. You then watch for the response via the same channel and reconstitute the TCP traffic from the remote side. Now the network is at your fingertips.

There’s more to it, but you can read about it in the post. It is slow, unreliable, and you definitely shouldn’t be doing it. But from the point of view of a clever hack, we loved it. In fact, [Robert] didn’t do it either. He proved it would work but did all the development using GitHub gist as the drop box. While we appreciate the hack, we also appreciate the ethical behavior!

Some airlines allow free messaging, which is another way to tunnel traffic. If you can connect to something, you can probably find a way to use it as a tunnel.