GB Interceptor Enables Live Screen Capture From Game Boy

December 22, 2022 by Zoe Skyforest 10 Comments

[Sebastian] had a tricky problem to solve. Competitors in a Tetris tournament needed to stream video of their Game Boy screens, but no solution readily existed. For reasons of fairness, emulators were right out, and no modifications could be made to the Game Boys, either. Thus, [Sebastian] created the GB Interceptor, a Game Boy capture cartridge.

Thanks to the design of the Game Boy, there’s plenty of access to useful signals via the cartridge port itself. [Sebastian] realized that a non-invasive capture device could be built to sit in-between the Game Boy and a cart, and send video to a computer. Unfortunately, there’s no direct access to the video RAM via this port, but [Sebastian] figured out a nifty workaround.

The build uses a Raspberry Pi Pico. The chip’s two cores emulate the Game Boy’s CPU and Picture Processing Unit, respectively. Doing this, while having the chips keep up with what’s going on in the Game Boy, required overclocking the Pico to 225 MHz. The system works by capturing data from the cartridge’s memory bus, and follows along with the instructions being run by the Game Boy. By doing this, the Pico is able to populate its own copy of the video RAM. It then spits this out over USB, where it can be displayed and streamed online as desired.

There are some edge-case limitations, but for its intended purpose, the system works great. Currently, the hardware is usable on Linux and Windows, though it does require some fiddling in the latter case. Files are on Github for those eager to build their own. If you simply want to dump carts rather than stream from your Game Boy, we can help there, too. Video after the break.

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You Can Make Ferrofluid On The Cheap With VHS Tapes

December 22, 2022 by Zoe Skyforest 34 Comments

Ferrofluid is a wonderous substance. It’s a liquid goop that responds to magnetic fields in exciting and interesting ways. It’s actually possible to make it yourself, and it’s cheap, too! The key is to get yourself some old VHS tapes.

The only fitting end for a copy of *Speed II.*

The trick is to separate the ferric oxide from the plastic tape inside the VHS cassette. Step one is naturally to smash open a cassette, and pull out the plastic tape from inside. The tape can then be dunked in acetone to dissolve the plastic, leaving behind the ferric oxide that once stored your cherished copy of Heat. A magnet is an easy way to collect the ferric oxide, which should then be left to dry. The powdery substance can then be blended in a ratio of 1 mL of ferric oxide to 0.333 mL of cooking oil. Poor mixing can be improved by adding a droplet of water mixed with dish detergent. You should end up with a brownish sludge that acts as a rudimentary ferrofluid.

It’s a neat bit of home science. As with most such activities, it bears noting the safety risks. Don’t leave your acetone uncovered to form a nasty flammable vapor, and keep yourself keenly aware of any fire or ignition risks. Overall though, it’s a fairly straightforward process. While the resulting material isn’t necessarily lab grade, you could potentially use it to build your own ferrofluid display!

2022 FPV Contest: A Poor Man’s Journey Into FPV

December 22, 2022 by Zoe Skyforest 4 Comments

FPV can be a daunting hobby to get into. Screens, cameras, and other equipment can be expensive, and there’s a huge range of hardware to choose from. [JP Gleyzes] has been involved with RC vehicles for many years, and decided to leverage that experience to do FPV on a budget.

Early experiments involved building a headset on the cheap by using a smartphone combined with a set of simple headset magnifiers. With some simple modifications to off-the-shelf hardware, [JP] was able to build a serviceable headset with a smartphone serving as the display. Further work relied upon 3D printed blinds added on to a augmented-reality setup for even better results. [JP] also developed methods to use a joystick to fly a real RC aircraft. This was achieved by using an Android phone or ESP32 to interface with a joystick, and then spit out data to a board that produces PPM signals for broadcast by regular RC hardware.

[JP] put the rig to good use, using it to pilot a Parrot Disco flying wing drone. The result is a cheap method of flying FPV with added realism. The first-person view and realistic controls create a more authentic feeling of being “inside” the RC aircraft.

It goes to show that FPV rigs don’t have to break the bank if you’re willing to get creative. We’ve seen some great FPV cockpit builds before, too.

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A Modern Tribute To The Classic HP-16C Calculator

December 21, 2022 by Zoe Skyforest 19 Comments

The HP-16C Computer Scientist is much beloved as the only dedicated programmer’s calculator that Hewlett-Packard ever made. Most surviving examples in the world are well-used, and you haven’t been able to order one from HP since 1989. Thus, [K Johansen] set about building a tribute to the HP-16C using modern hardware.

The build relies on a Raspberry Pi Pico as the brains of the operation. As with so many classic HP calculators, it operates in Reverse Polish Notation, and includes the customary stack operations. To serve a programmer well, it’s set up to accept entry in hexadecimal, octal, decimal, and binary formats, and can readily convert between them. Beyond that, it’s equipped with the usual arithmetic operators, as well as bitwise operations like NOT, AND, and so on.

Perhaps what we love most, though, is the keypad. It was all put together with a combination of cheap AliExpress keypads, a label maker, and a laser printer. It’s a wholly DIY job, and a little rough around the edges, but it makes the calculator far easier to use.

It’s not an exact replica of the HP-16C, but the differences in operation are minor.Those wishing to build their own can grab the required files from the project’s Github page. We’ve seen replicas of other classic HP calculators before, too. If you’ve got your own mathematical projects brewing up in the lab, don’t hesitate to send them in to the tipsline!

LED Christmas Lights Optimized For Max Twinkleage

December 21, 2022 by Zoe Skyforest 12 Comments

Old-school filament-based Christmas lights used to be available in twinkling form. LEDs, with their hard-on and hard-off nature, aren’t naturally predisposed to such behavior. To rectify this, some time ago, [Mark Kriegsman] built an Arduino program that makes LEDs twinkle beautifully.

The program is known as TwinkleFOX, and relies on the popular FastLED library for addressable LEDs. [Mark’s] demo setup is built around using WS2811 LEDs, put together in a string with plastic diffusers on each bulb. The Arduino is programmed to vary the brightness of each LED according to a triangle wave function. To create the twinkling effect, each LED has its own unique clock signal, so they vary in brightness at different times and at different rates.

Using an Arduino Uno or Leonardo, [Mark] reports its possible to twinkle 300 individual LEDs at a rate of over 50 updates a second. Using a faster microcontroller should net reliable performance with longer strings. Meanwhile, if you’re wondering how the older-style lights used to twinkle, we’ve covered that before too. Video after the break.

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2022 FPV Contest: The LOTP Robot Dog

December 21, 2022 by Zoe Skyforest 7 Comments

When you think of first person view (FPV) vehicles, aircraft might be what first comes to mind. However, [Limenitis Reducta] has brought a robot dog into the world, and plans to equip it for some FPV adventures.

LOTP pictured with various equippable modules.

The robot dog itself goes by the name of LOTP, for unspecified reasons, and was designed from the ground up in Fusion 360. A Teensy 3.5 is charged with running the show, managing control inputs and outputting the requisite instructions to the motor controllers to manage the walk cycle. Movement are issued via a custom RC controller. Thanks to an onboard IMU, the robotic platform is able to walk effectively and maintain its balance even on a sloping or moving platform.

[Limenitis] has built the robot with a modular platform to support different duties. Equitable modules include a sensor for detecting dangerous gases, a drone launching platform, and a lidar module. There’s also a provision for a camera which sends live video to the remote controller. [Limenitis] has that implemented with what appears to be a regular drone FPV camera, a straightforward way to get the job done.

It’s a fun build that looks ready to scamper around on adventures outside. Doing so with an FPV camera certainly looks fun, and we’ve seen similar gear equipped on other robot dogs, too.

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Blood Pressure Monitoring, Courtesy Of Cameras And AI

December 21, 2022 by Zoe Skyforest 60 Comments

At the basic level, methods of blood pressure monitoring have slowly changed in the last few decades. While most types of sphygmomanometer still rely on a Velcro cuff placed around the arm, the methodology used in measurement varies. Analog mercury and aneroid types still abound, while digital blood pressure monitors using electrical sensors have become mainstream these days.

Researchers have now developed a new non-invasive method of measurement that does away with the arm cuff entirely. The method relies entirely on video capture with a camera and processing via AI.

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