classic hacks

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The Clickiest Game Of Tetris You’ll Ever Play, On A Flip-Dot

May 14, 2019 by 12 Comments

Like many other classics it’s easy to come up with ways to ruin Tetris, but hard to think of anything that will make it better. Adding more clickiness is definitely one way to improve the game, and playing Tetris on a flip-dot display certainly manages to achieve that.

The surplus flip-dot display [sinowin] used for this version of Tetris is a bit of an odd bird that needed some reverse engineering to be put to work. The display is a 7 x 30 matrix with small dots, plus a tiny green LED for each dot. Those LEDs turned out to be quite useful for replicating the flashing effect used in the original game when a row of blocks was completed, and the sound of the dots being flipped provides audio feedback. The game runs on a Teensy through a custom driver board and uses a Playstation joystick for control. The video below, in perfectly acceptable vertical format, shows the game in action and really makes us want to build our own, perhaps with a larger and even clickier flip-dot display.

The best thing about Tetris is its simplicity: simple graphics, simple controls, and simple gameplay. It’s so simple it can be played anywhere, from a smartwatch to a business card and even on a transistor tester.

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Video Doorbell Focuses On Quality, Aesthetic

May 13, 2019 by 2 Comments

One of the most popular futurist tropes of the 20th century was the video intercom. Once this technology was ready, it would clearly become a mainstay of modern living overnight. Our lived reality is however somewhat different. For [MisterM], that simply wouldn’t do, so he set about producing a retro-themed video doorbell that is sure to be the envy of the neighbourhood.

Not one to settle for second best, [MisterM] wanted to focus on quality in video and sound. A Microsoft LifeCam 3000HD handles video and audio capture, with a Raspberry Pi 3B+ providing plenty of grunt to run the show. The Pimoroni pHAT BEAT add-on provides audio output. It’s all integrated into a 1980s vintage intercom, which is painted a deep shade of maroon for an extra classy look. Further parts are integrated into a classic Sony tape deck, with LEDs shining out from under the cassette door for added visual appeal.

The doorbell works by making calls to Google Duo, which allows the user to answer the door from anywhere in the house, or indeed – anywhere with an Internet connection! [MisterM] reports this has already proved useful for communicating with couriers delivering packages to the house. There’s also a standard wireless doorbell and chime integrated into the unit which alerts those within the house in the usual way.

It’s a project that is both highly functional and looks particularly swish. Integrating new brains into old-school enclosures is a great way to give your project a cool look. These aircraft surplus clocks are a great example. Video after the break.

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Better Debating Through Electronics

May 12, 2019 by 8 Comments

Watch any news panel show these days, and you’ll see that things can very quickly become unruly. Guests compete for airtime by shouting over one another and attempting to derail their opponent’s talking points. [cutajar.sacha] had encountered this very problem in the workplace, and set about creating a solution.

The result is the Debatable Deliberator, and it combines the basics of “Talking Stick” practices with behavioural training through humiliation. Two participants each wear a headband, fitted with electronics. The holder of the magic ball may speak for as long as the timer counts down. If their opponent speaks during this time, their headband reprimands them with gentle slapping to the face. If the holder speaks over their assigned time, they are similarly treated to mechanical slapping.

It’s an amusing way to help police a discussion between two parties, and it’s all made possible with a trio of WeMos D1 ESP8266 boards. The headbands act as clients, while the ball acts as a server and keeps track of how many times each speaker has broken the rules.

WiFi projects such as this one have become much easier in the past few years with the wide availability of chips like the ESP8266. Of course, if you need more grunt, you can always upgrade to the ESP32.

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Edge Lit Pendant, Is, Well… Lit

May 7, 2019 by 3 Comments

Acrylic is a great material. It’s not cheap, but it comes in a wide variety of colours and styles and can be used to make some very attractive projects. [Geek Mom Projects] is a big fan, and whipped up some fun pendants for a high school Maker Faire.

[Geek Mom] has long been a fan of edge-lighting, as it’s a great way to make beautiful glowy projects out of acrylic. In this case a fluorescent acrylic is used with white LEDs to generate an eerie green glow, though it’s also noted that the project can be done with clear acrylic and color-shifting LEDs instead for an equally cool look. If you’re filming a low-budget sci-fi film, this could be just what you need.

The pendants made a great project for young makers to learn about LEDs, electronics, and technologies such as lasercutting that were used to produce the parts. With copper tape used instead of soldering and a CR2032 battery used to eliminate the need for a current limiting resistor, it’s a very accessible project that most teens were able to complete without assistance.

It’s not the first time we’ve seen edge-lit pendants, either. Alternatively, if you need your acrylic bent, there’s a tool for that, too.

Creating A Touch Pad Without Dedicated Hardware

May 2, 2019 by 5 Comments

Year on year, microcontrollers and development platforms are shipping with ever-increasing feature sets. In the distant past, if you wanted an analog to digital converter or a PWM driver, you had to tack extra ICs on to your design. Nowadays, it’s all baked in at the factory. Of course, you may still find yourself working with a platform that lacks capacitive touch inputs. That’s no problem, though – you can do it all without dedicated hardware anyway!

Capacitive touch sensing works by creating an RC oscillator, and allowing the user to affect the capacitance in the circuit through touch or proximity. By sensing the changes in the frequency of the oscillator, it’s possible to determine whether the object or pad is being touched or not. As the capacitance changes can be small, sometimes it’s desired to use a high frequency oscillator, and then pass the output through a frequency divider, which allows changes to be measured more easily by a slower microcontroller.

[Gabriel] does a great job of both explaining the theory involved, as well as presenting a practical way to achieve this with basic hardware. If you need to add touch sensitivity to an existing or otherwise limited platform, this is an easy way to go about doing it. There are definitely some interesting things you can do with the technology, after all.

Parasite ATtiny Resets Your ESP32 For You

May 1, 2019 by 28 Comments

Embedded development can be a tough process. Between weird electrical gremlins, obscure bugs and our own mistakes, it can be a real struggle at times. To keep cognitive loads to a minimum, it’s best to make sure your tools are as simple and easy to use as possible. [tech] got tired of having to push a button to prepare the ESP32 for programming, and decided to solve the problem.

The solution comes via another microcontroller, in this case an ATtiny9. The small device listens in on the ESP32’s serial receiving pin. When it detects the Arduino IDE’s boot sequence on the line, it switches the BOOT0 and RESET lines on the ESP32, emulating the button presses to force it into programming mode.

Once you’ve become accustomed to one-click programming your ESP boards, you’re not going to want to go back. We could imagine this hack being replicated in a tidy piggyback format so it could be moved from board to board as workflow dictates.

If you’ve got an ESP32 lying around and don’t know what to do with it, you could always consider getting into game development.

 

3D Printing A Water Jet Drive

April 30, 2019 by 16 Comments

[Ivan Miranda] is always experimenting with 3D printing, and recently has been taking his work on the water. His latest creation is a racing paddle boat, but its performance left [Ivan] with a need for speed. Cue the development of the 3D printed water jet engine (YouTube link, embedded below).

The basic principle of operation is simple. Water is sucked through an inlet, where it is accelerated by a turbine driven by a brushless motor. This turbine, in combination with stator fins, forces the water through the outlet, propelling the boat forwards in the process.

The first prototype is printed in PLA. Tolerances are good, thanks largely to [Ivan]’s experience and well-calibrated printers. After assembly, the engine is fired up, to great results. After sourcing a series of larger tubs in which to test the device, the engine is finally run up to full throttle and appears more than capable of shifting a serious amount of water.

We’d love to see a proper instrumented thrust test, particularly one that compares the device to other water jet drives on the market. Brushless motors make a great drive solution for RC boats, so we’re sure [Ivan] will be tearing up the lake real soon. Video after the break.

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