Dozens Of Servos Flip The Segments Of This 3D-Printed Digital Clock

December 10, 2018 by Dan Maloney 16 Comments

A digital clock based on seven-segment displays? Not exciting. A digital clock with seven-segment displays that’s really big and can be read across a football field? That’s a little more interesting. A large format digital clock that uses electromechanical seven-segment displays? Now that’s something to check out.

This clock comes to us by way of [Otvinta] and is a nice example of what you can do with 3D-printing and a little imagination. Each segment of the display is connected to a small hobby servo which can flip it 90°. Mounted in a printed plastic frame, the segments are flipped in and out of view as needed to compose the numerals needed to display the time. The 28 servos need two Pololu controller boards, which talk to a Raspberry Pi running Windows IoT, an interesting design choice that we don’t often see. You’d think that 28 servos clattering back and forth might be intolerable, but the video below shows that the display is actually pretty quiet. We’d love to see this printed all in black with white segment faces, or even a fluorescent plastic; how cool would that look under UV light?

We’re not saying this is the only seven-segment servo clock we’ve seen, but it is a pretty slick build. And of course there’s more than one way to use servos to tell the time.

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An Over-engineered LED Sign Board

December 8, 2018 by Inderpreet Singh 10 Comments

Never underestimate the ability of makers in over thinking and over-engineering the simplest of problems and demonstrating human ingenuity. The RGB LED sign made by [Hans and team] over at the [Hackheim hackerspace] in Trondheim is a testament to this fact.

As you would expect, the WS2812 RGB LEDs illuminate the sign. In this particular construction, an individual strip is responsible for each character. Powered by an ESP32 running FreeRTOS, the sign communicates using MQTT and each letter gets a copy of the 6 x 20 framebuffer which represents the color pattern that is expected to be displayed. A task on the ESP32 calculates the color value to be displayed by each LED.

The real question is, how to calibrate the distributed strings of LEDs such that LEDs on adjacent letters of the sign display an extrapolated value? The answer is to use OpenCV to create a map of the LEDs from their two-dimensional layout to a lookup table. The Python script sends a command to illuminate a single LED and the captured image with OpenCV records the position of the signal. This is repeated for all LEDs to generate a map that is used in the ESP32 firmware. How cool is that?

And if you are wondering about the code, it is up on [Github], and we would love to see someone take this up a level. The calibration code, as well as the Remote Client and ESP32 codes, are all there for your hacking pleasure.

Its been a while since we have seen OpenCV in action like with the Motion Tracking Turret and Face Recognition. The possibilities seem endless. Continue reading “An Over-engineered LED Sign Board” →

Artistic Images Made With Water Lens

December 7, 2018 by Bryan Cockfield 15 Comments

It’s said that beauty and art can be found anywhere, as long as you look for it. The latest art project from [dmitry] both looks in unassuming places for that beauty, and projects what it sees for everyone to view. Like most of his projects, it’s able to produce its artwork in a very unconventional way. This particular project uses water as a lens, and by heating and cooling the water it produces a changing image.

The art installation uses a Peltier cooler to periodically freeze the water that’s being used as a lens. When light is projected through the frozen water onto a screen, the heat from the light melts the water and changes the projected image. The machine uses an Arduino and a Raspberry Pi in order to control the Peliter cooler and move the lens on top of the cooler to be frozen. Once frozen, it’s moved again into the path of the light in order to show an image through the lens.

[dmitry] intended the project to be a take on the cyclical nature of a substance from one state to another, and this is a very creative and interesting way of going about it. Of course, [dmitry]’s work always exhibits the same high build quality and interesting perspective, like his recent project which created music from the core samples of the deepest hole ever drilled.

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1970s Lab Equipment Turned Retro Pi Terminal

December 5, 2018 by Tom Nardi 20 Comments

When it was released, the Beckman Model 421 CRT controller represented the latest and greatest in liquid chromatography technology. Its 12 inch screen would allow the operator to view critical information such as flow rate and concentration, and its integrated keyboard simplified system control. It made liquid chromatography faster and easier, allowing lab technicians to focus on analysis rather than the complexities of operating the equipment.

But none of that matters right now. What matters is that [Igor Afanasyev] found one of these gloriously vintage devices at a local swap meet and decided it deserved a second chance at life. With a Raspberry Pi and a surprising amount of support hardware, he was able to turn this roughly 40 year old piece of scientific equipment into a multipurpose device that does everything from classic gaming to multimedia playback. It’s got a few quirks, but overall this is a gadget that any hacker would love to have kicking around their modern-day lab.

[Igor] explains that the Model 412 is essentially just a dumb terminal with no internal logic, so in theory it should have been possible to just hang the thing on a serial port and be done with it. But unfortunately the display drive board was dead, so a full rebuild was in order. This meant that there’s little left of the original device other than the keyboard and the case itself, but since it isn’t exactly a “vintage computer” in the traditional sense, we think the purists will allow it.

For the display, [Igor] used an LCD he salvaged from an old digital picture frame. It was the right size to fit the opening, and thanks to an unpopulated VGA header on the board, wasn’t too difficult to get connected to the Pi with an HDMI adapter. He also added a hardware VGA scanline generator board so that no matter what the Pi shows it will have that classic old-school look; a fantastic detail we don’t usually see on builds like this.

The keyboard on the Model 412 was more of a control panel than a traditional input device, so not only does it have keycaps which say things like “FLOW RATE” and “WRITE TAPE”, but it has a fairly weird layout. After reverse engineering the somewhat unusual key matrix, he spun up a custom firmware for the Arduino Pro Micro using QMK which would let him use the board on the Pi as a standard USB input device. But rather than replace the keys, [Igor] created a little cheat-sheet overlay that he could put over the board to see what keys translate to which letters. It’s awkward for sure, but we really appreciate that he preserved the unique nature and look of the Model 412.

Like the Heathkit H19 that was brought back to life with an internal Raspberry Pi or the DEC VT100 with a BealeBone inside there’s something about the visual aesthetic and no-nonsense approach of these vintage terminals which continue to make them compelling into the 21st century.

Editing GameCube Memory With A Raspberry Pi

December 5, 2018 by Brian Benchoff 1 Comment

[James] has been working with GameCubes, emulators, and Animal Crossing for a while now, and while emulators are sufficient, he’d like to play on real hardware. This means he needs to write to a GameCube memory card. While there are a few options to do this, they either require a Wii or hardware that hasn’t been made in a decade. The obvious solution to this problem is to reverse engineer the GameCube memory card to read and write the memory with a Raspberry Pi.

There’s an incredible amount of unofficial documentation for every console, and [James] stumbled upon a GC-Forever forum post that describes the electrical signals inside the GameCube memory card. There’s your standard compliment of power and ground pads, along with a DI, DO, CS, Clk, and an INT pin. [James] broke out the magnet wire and soldered up a pin header to these cards. Data was then captured with a Salae logic analyzer, and lo and behold, it looked like a standard SPI protocol.

With the low-level protocol worked out, [James] checked out the Yet Another GameCube Documentation to get the main functions allowed through the SPI bus. The ‘read block’, for instance, starts off with 0x52 and an address offset. A little bit of Python on a Raspberry Pi meant [James] could read and write the entire GameCube memory card. Right now the code is a little rough, but all the work is available should you want to edit your Animal Crossing save with a Raspberry Pi.

This work follows [James]’ earlier work on getting into the debug menu of Animal Crossing, allowing him to add items to his inventory. With this latest advancement, it’s only a matter of time before we plug Raspberry Pis directly into a GameCube.

Wheel Of Fortune Gets Infinite Puzzles On NES

December 2, 2018 by Lewin Day 20 Comments

Wheel of Fortune is a television game show, born in the distant year of 1975. Like many popular television properties of the era, it spawned a series of videogames on various platforms. Like many a hacker, [Chris] had been loading up the retro NES title on his Raspberry Pi when he realized that, due to the limitations of the cartridge format, he was playing the same puzzles over and over again. There was nothing for it, but to load a hex editor and get to work.

[Chris’s] initial investigation involved loading up the ROM in a hex editor and simply searching for ASCII strings of common puzzles in the game. Initial results were positive, turning up several scraps of plaintext. Eventually, it became apparent that the puzzles were stored in ASCII, but with certain most-significant-bits changed in order to mark the line breaks and ends of puzzles. [Chris] termed the format wheelscii, and developed an encoder that could turn new puzzles into the same format.

After some preliminary experimentation involving corrupting the puzzles and testing various edge cases, [Chris] decided to implement a complete fix. Puzzles were sourced from the Wheel of Fortune Puzzle Compendium, which should have plenty of fresh content for all but the most addicted viewers. A script was then created that would stuff 1000 fresh puzzles into the ROM at load time to minimize the chances of seeing duplicate puzzles.

ROM hacks are always fun, and this is a particularly good example of how simple tools can be used to make entertaining modifications to 30-year-old software. For another take, check out this hack that lets the Mario Bros. play together.

Arcade1up Cabinet Solderless Upgrade With A Side Of Raspberry Pi

December 1, 2018 by Drew Littrell 17 Comments

Upon announcement of the Arcade1up replica arcade cabinets earlier this year, many laid in waiting for the day they could see a teardown. A four foot tall cab with an LCD outputting the proper 4:3 aspect ratio and the simple construction of IKEA furniture certainly seemed appealing. In theory, it wouldn’t take long to customize such a piece of hardware provided the internals lent themselves to that sort of thing. Now that the cabinets are on store shelves, [ETA Prime] made a tutorial video on his method for upgrading the Arcade1up cabinet with a Raspberry Pi calling the shots.

The entirety of the mod is solder-free and uses plenty of readily available parts from your favorite online reseller. The brains of the operation is a Raspberry Pi 3 Model B+ running Emulation Station. The Arcade1up Street Fighter 2 cabinet’s less than stellar audio receives an upgrade in a 2x20W car audio amp, while the middling joysticks are swapped out for some more robust Sanwa-clone ball tops.

Since there is no “select/coin” button natively, [ETA Prime] added some and in the process replaced them all with beefier LED-lit 30mm buttons. The replacement joysticks and buttons were all part of a kit, so they plug-in conveniently to a plug and play USB encoder. To adapt the 17″ LCD’s output over LVDS, [ETA Prime] elected to go with an LCD controller board that outputs DVI, VGA, or HDMI. Luckily the Arcade1up cabinet’s 12V power supply could be reused to power the LCD controller board and in the process bring down the overall cost of the upgrade.

While this Arcade1up cabinet mod won’t solve the whole “bats versus ball tops” argument, it does provide a template to build on. The tutorial video is below and the list of parts used can be found in the YouTube description.

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