DIY Handheld Game Puts Its Brains On A Removable Cart

August 16, 2021 by 10 Comments

Over the years we’ve seen plenty of homebrew handheld game systems that combine an AVR microcontroller, a few buttons, and an small OLED display. Some of them have even been turned into commercial products, such as the Arduboy. They’re simple, cheap, and with the right software, a lot of fun. But being based on an MCU, most of them share the same limitation of only being able to hold a single game at any one time.

But not the Game Card, by [Dylan Turner]. This handheld was specifically designed so that games could be easily swapped out using physical cartridges. But rather than trying to get the system’s microcontroller to boot code from an external flash chip, the system relocates the MCU to the removable cartridge. That might seem a bit overkill, but given how cheap the ATTINY84A on each cartridge is, it’s not exactly going to break the bank.

With the microcontroller on the cartridge, the only hardware that stays behind on the Game Card is the SSD1306 128×64 OLED display, buttons, and the battery. That means the handheld is effectively non-functional unless a game is slotted in, but that could be said of most early cartridge-based game systems as well. On the other hand, it also opens up the possibility of producing cartridges with more powerful microcontrollers down the line.

Using a different microcontroller for each game is a neat hack, but it’s not the only solution to the problem. We previously saw a community effort to add expandable storage to the Arduboy in the form of a DIY cartridge, which ultimately led to the development of an official flash chip upgrade for the handheld.

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Hackaday Podcast 127: Whippletree Clamps, Sniffing Your Stomach Radio, Multimeter Hum Fix, And C64 Demo; No C64

July 16, 2021 by No comments

Hackaday editors Mike Szczys and Elliot Williams help you get caught up on a week of wonder hacks. We don’t remember seeing a floppy drive headline the demoscene, but sure enough, there’s a C64 demo that performs after the computer is disconnected. What causes bench tools to have unreliable measurements? Sometimes a poor crystal choice lets AC ruin the party. We dive into the ongoing saga of the Audacity open source project’s change of ownership, and talk about generator exciter circuits — specifically their role in starting grid-scale generators from shutdown.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Tetris Handheld Powered By Tritium Cell, Eventually

July 14, 2021 by 30 Comments

The idea of a tritium power cell is pretty straightforward: stick enough of the tiny glowing tubes to a photovoltaic panel and your DIY “nuclear battery” will generate energy for the next decade or so. Only problem is that the power produced, measured in a few microwatts, isn’t enough to do much with. But as [Ian Charnas] demonstrates in his latest video, you can eke some real-world use out of such a cell by storing up its power over a long enough period.

As with previous projects we’ve seen, [Ian] builds his cell by sandwiching an array of keychain-sized tritium tubes between two solar panels. Isolated from any outside light, power produced by the panels is the result of the weak green glow given off by the tube’s phosphorus coating as it gets bombarded with electrons. The panels are then used to charge a bank of thin-film solid state batteries, which are notable for their exceptionally low self-discharge rate.

Some quick math told [Ian] that a week of charging should build up enough of a charge to power a knock-off handheld Tetris game for about 10 minutes. Unfortunately, after waiting the prescribed amount of time, he got only a few seconds of runtime out of his hacked together power source.

His best guess is that he got a bad batch of thin-film batteries, but since he could no longer find the exact part number he used originally, he had to design a whole new PCB for the second attempt. After waiting two long months to switch the game on this time, he was able to play for nearly an hour before his homebrew nuclear energy source was depleted.

We wouldn’t consider this terribly practical from a gaming standpoint, but like the solar harvesting handheld game we covered last year, it’s an interesting demonstration of how even a minuscule amount of power can be put to work for intermittent applications. Here it’s a short bout of wonky Tetris, but the concept could just as easily be applied to an off-grid sensor.

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Hacking A Thermal Imager For Dual-use Of The Thermal Sensor

July 4, 2021 by 3 Comments

Sometimes a device doesn’t do quite what one needs, and in those cases a bit of tampering might do the trick. That’s what led to being able to record video from a HTI HT-A1 thermal imager despite the device not actually supporting that function, thanks to careful investigation and warranty violation.

Plugging in a custom USB cable allows a mobile phone app to access the thermal sensor, while the host device itself remains ignorant.

We’ve seen a teardown of the HT-A1 in the past, and it turns out that Seek — the manufacturer for the actual thermal sensor inside the device — released an OEM development kit and mobile phone app for their modules. Could this mean that the raw sensor module in the HT-A1 could be accessed via the developer kit app? One hacked together USB cable later showed that the answer is yes! Not only does the app allow viewing thermal imagery, but it makes it possible to do things like record video (a function the HT-A1 itself does not support.)

But even if the HT-A1 doesn’t allow recording, as a handheld thermal sensor with a screen it’s still pretty useful in its own way and it would be shame to gut the unit just for a raw sensor module. The best solution ended up being to put the sensor back into the HT-A1, and install some switching circuitry to disconnect the sensor from the HT-A1’s CPU and divert its data to the USB plug on demand. This means the HT-A1 can be used normally, but by plugging in a custom-made cable while the unit is off, the thermal sensor can be accessed by the mobile phone app instead. Best of both worlds. You can see a brief celebratory thermal cat video embedded below, proving it works.

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Turning The Virtual Boy Into A Handheld Console

June 10, 2021 by 9 Comments

The Virtual Boy, Nintendo’s most infamous failure, was plagued by several issues. The most glaring problem was the red monochrome stereoscopic display technology which gave many users a headache after even a short time playing, but it’s sky-high price and extremely limited library of games kept many prospective buyers at bay as well. There was also the issue of portability: unlike the Game Boy it was named after, the Virtual Boy barely qualified as a portable system due to the fact it needed to be set up on a table to use.

But now, thanks to the tireless efforts of [Shank], at least a few of those issues have been resolved. He’s built the world’s first truly portable Virtual Boy, which swaps the system’s troubled 3D display for a modern IPS LCD panel. The custom handheld, designed to merge the Virtual Boy’s unique aesthetic with the iconic styling of the Game Boy Advance, looks like it came from some alternate timeline where Nintendo decided to produce a cheaper and less cumbersome version of the system rather than abandoning it.

While the work [Shank] has put into the project is unquestionably impressive, it should be said that it took the efforts of several talented hackers to create the handheld Virtual Boy. The key component that made the modification possible in the first place is the VirtualTap by [Furrtek], which not only provides the VGA output that’s driving the LCD panel, but fools the system’s motherboard into believing the servo-actuated stereoscopic display is still connected and active.

It’s also using the open source power management board that [GMan] originally developed for his own portable N64, [Bassline] chipped in to cast the custom buttons and D-pad in translucent resin, and [Mitch 3D] put an untold number of hours into printing and reprinting the system’s multicolored enclosure until it came out just right.

All the little details of the final system, which [Shank] calls the Real Boy, put this project into a league of its own. Special combinations of button presses allows the user to change the color of the display, should you get sick of the infamous red-tint. The buttons also have RGB LEDs behind them that correspond with the color scheme of the display itself, for that extra bit of gamer cred. He even made sure to include the system’s original link port, despite the fact that no officially released game ever made use of it.

Our first run in with [Shank] was when he demoed a portable Wii built into a mint tin. It made for a pretty pitiful gaming experience, but the project demonstrated his dedication to seeing a project through to the end. Watching his skills improve over the last few years has been inspiring, and we can’t wait to see what he comes up with next.

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Soldering Iron Plus Camera Gimbal Helps Cancel Out Hacker’s Hand Tremors

June 4, 2021 by 39 Comments

Soldering requires steady hands, so when [Jonathan Gleich] sadly developed a condition called an essential tremor affecting his hands, soldering became much more difficult. But one day, while [Jonathan] was chatting with a friend, they were visited by the Good Ideas Fairy and in true hacker fashion, he ended up repurposing a handheld camera stabilizing gimbal to hold a soldering iron instead of a camera or smartphone. Now instead of the gimbal cancelling out hand movements to keep a camera steady, it instead helps keep a soldering iron steady.

While the inner workings of the cheap gimbal unit didn’t need modification, there were a couple of things that needed work before the project came together. The first was to set up a way to quickly and easily connect and disconnect the soldering iron from the gimbal. Thanks to a dovetail-like connector, the iron can be safely stored in its regular holster and only attached when needed.

The other modification is more subtle. The stabilizer motors expect to be managing something like a smartphone, but a soldering iron is both lighter and differently balanced. That meant that the system worked, but not as well as it needed to. After using some small lead weights to tweak the mass and center of gravity of the soldering iron — making it feel and move a bit more like an iPhone, as far as the gimbal was concerned — results were improved.

The soldering iron stabilizer works well enough for now, but we don’t doubt that [Jonathan] already has further tweaks in mind. This is a wonderful repurposing of a consumer device into an assistive aid, so watch it in action in the short video embedded below.

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Handheld Multimeter Converted For Bench Top Use

May 31, 2021 by 14 Comments

A few years ago [Mechatrommer] got one of the low-cost Aneng Q1 multimeters and has converted it into a bench top meter. He first tried and failed to do an LCD modification and set it aside. It remained in a storage box until he needed another meter to repair his rubidium frequency standard. Finding that off-the-shelf bench multimeters were literally off-the-shelf — they were too deep for his bench — he decided to take matters into his own hands.

He dug out the dismantled an Aneng Q1 and undertook a more drastic modification than before, slicing the multimeter into three pieces and mounting each piece in a new enclosure. The power-draining back-lit display of the Q1, problematic in a battery-powered handheld meter, isn’t an issue in a bench top design. [Mechatrommer] replaced the battery pack with a mains powered supply. Next he reconnected all the signals which had been interrupted by the bandsaw, and now the meter lives again.

The resulting meter is pleasing enough (ignore the sideways input jacks) and looks like a typical piece of home-brew test gear. The enclosure has a lot of empty space, which he uses to stow test leads and sandwiches (we saw a similar storage compartment in [Dave Jones]’s recent teardown of a portable Fluke 37 multimeter). Kudos to [Mechatrommer] for coming up with this unusual conversion project.

We’ve written about the differences between these low-cost and more professional multimeters before if you want to learn more.

Thanks to [Adrian] for the tip.