Author: Zoe Skyforest

3719 Articles

Voice-Command Chess Board Powered By Alexa

June 22, 2020 by 6 Comments

Talking to computers used to be reserved for Star Trek and those with overactive imaginations. Now, it’s a regular part of daily life. [CodersCafe] decided to put this technology to work in a chess robot, with the help of Amazon’s digital assistant. 

The build relies on an Cartesian motion rig, built out of Lego Technics parts. The end effector is fitted with a magnet , fitted onto the Z-axis screw for engaging and disengaging with the pieces. A Mindstorms EV3 controller is used to run the show, hooked up over Bluetooth to an Amazon Echo. This allows the user to ask Alexa to move the pieces for the white player in natural language – by saying, for example, “move from B1 to C3”.

It’s a build that demonstrates how easy it is to create projects with advanced functionality by lacing together the correct off-the-shelf hardware. Other Cartesian-type motion platforms can make great chess robots, too. Video after the break.

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3D Printing Transmission Line Speakers

June 21, 2020 by 9 Comments

Anyone who has played with speakers on the workbench knows the huge difference enclosure design makes to the frequency response of an audio system. Speakerheads spend hours tinkering with designs and calculations, aiming to get the best out of a given set of drivers. [HexiBase] decided to try some experiments of his own, running into some hurdles along the way.

[Hexibase] aimed to 3D print a compact transmission line design, to suit a pair of 1 1/8″ full-range drivers. Being aware of the benefits of high-resolution resin 3D printing, he set out to print a design taking full advantage of the build volume of his Longer 3D Orange 30 printer. Unfortunately, after much fiddling with slicer settings, the printer turned out to have a fundamental fault, leading to unusable prints.

Undeterred, [Hexibase] switched to using his Longer FDM model instead. Printing out the enclosures in PLA. he noted that the different material will have a slightly altered frequency response than originally intended. Regardless, the final result sounds great, and barring some higher-frequency anomalies, the output correlates well with the mathematical model of expected performance.

3D printers make great tools for budding speaker builders, as they make constructing advanced geometries a cinch. Of course, you can even try and 3D print the drivers themselves if you’re so inclined. Video after the break.

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VGA Framegrabber Built From Scratch

June 21, 2020 by 35 Comments

Modern computers are replete with all manner of digital video interfaces. DVI, HDMI, DisplayPort are all examples of this. In the old days, VGA ruled the roost, sending video to monitors as an analog signal. However, it’s possible to convert this back into a digital format, and [vihapuu] has done just that with his Grabor project. (a demo video is also embedded below.)

The project relies on a Texas Instruments TVP7002 to do the hard work of converting VGA into a digital signal. The output of this chip is then picked up by a CPLD which clocks the resulting data into SRAM. An NXP microcontroller is then responsible for taking the data from SRAM and sending it out over a network interface, thanks to a Microchip ENC28J60 Ethernet controller.

We can imagine this kind of tool would come in handy for working with retro machines over a network. We’ve seen other interesting VGA hacks before too, like this EEPROM-based signal generator. Video after the break.

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Wurlitzer Note Visualizer Gets A 2020-Spec Replica

June 20, 2020 by 1 Comment

Way back in the 1970s, when smog laws were choking American V8s and the oil crisis was in full swing, Wurlitzer released their Key Note Visualizer. Intended as a teaching aid, the device lit up keys on a keyboard graphic, allowing an organ player to visually demonstrate their performance to a class. [Guy Dupont] set out to replicate this hardware, but with a modern twist.

The build consists of an ESP-32, which accepts MIDI data over Bluetooth Low Energy. This is then used to light up a series of RGB LEDs on a musical staff and a keyboard graphic, corresponding to the notes being played. The LEDs used are the old-school four-wire type, rather than more modern data-driven types. They’re placed in 3D-printed holders which serve to stop the light from each LED bleeding into adjacent areas. The faceplate is made of acrylic, stencilled with that classic orange paint and with vinyl decals applied for the markings. It’s all wrapped up in a walnut case, which [Guy] CNC machined himself.

It’s a tidy build that faithfully recreates the 1970s aesthetic of the original. We plaintively wish that manufacturers would release more electronics in walnut enclosures, though ask politely that they leave cheap veneer in the past where it belongs.

Of course, if you like your musical displays more abstract than instructional, try this giant oscilloscope visualisation on for size. Video after the break.

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Smartglove Helps Cyclists Be Seen

June 20, 2020 by 25 Comments

Cyclists share the road with other vehicles, often leading to problems when drivers fail to see or respect the rider’s space. To try and alleviate these issues, [Matlek] built the Smartglove to help cyclists communicate their intentions to other road users.

The project consists of a glove fitted with an Arduino Nano 33 BLE sense, featuring Bluetooth and motion sensing on board. Combined with TinyML machine learning code, the Arduino is able to sense hand gestures from the rider. These gestures are then interpreted, and relevant messages displayed on an LED screen worn on the rider’s back. Flicking the wrist left and right flashes indicators that the user is about to change direction, while a rearward flick flashes a warning that the user is braking.

It’s a tidy way to integrate vehicle-style lighting into a simple interface for cycling. This has benefits, particularly at night, for allowing other road users to see a cyclist and understand their intentions on the road. Of course, if you really want to be noticed, this bike boombox could also be a big help. Video after the break. Continue reading “Smartglove Helps Cyclists Be Seen” →

Scanning Analog Film For The Last Time

June 19, 2020 by 44 Comments

Film cameras are capable of great resolution, and for a long time were superior in this regard to their digital successors. However, it’s now possible to store digital copies of analog images in superior detail, so [Jan] built a rig to scan their photos for the last time.

The general idea is to take a high enough resolution scan of film negatives or slides, such that there is no need to rescan the images when technology moves forward. To achieve this, [Jan] decided to employ a DSLR to photograph the materials in question. To do this quickly and accurately, with minimal fuss, special lens hoods were 3D printed to hold slides in perfect register in front of the lens. With a flash to provide even light, the results are excellent. Film negatives proved harder, requiring a carefully designed transport mechanism to avoid damaging the fragile materials. With some perseverance, the final tool worked well.

It’s a tidy way of digitally archiving analog photos, and with the resolution of modern cameras, one needn’t worry about lost resolution. We’ve seen mechanised builds for handling other formats too, such as this 8mm scanner. Video after the break.

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Up Your Home Network Performance – Build Your Own Router!

June 19, 2020 by 118 Comments

Internet connections continue to increase in speed, and for a lucky few, it’s possible to get a Gigabit fibre connection at home. However, if you’re intending to use this connection to its fullest, you might find that your off-the-shelf router has become a bit of a bottleneck. [Wes Fenlon] of PC Gamer had this very problem, and found the perfect workaround – building a custom router instead!

The main problem with commodity routers is a lack of processing power. With networks growing ever faster, the hardware in routers hasn’t kept up with the needs of demanding power users. To solve this, [Wes] grabbed an old PC he had lying around, packing a quad-core i5 CPU and 16 GB of RAM. Fitted with an enterprise-grade 4-port Gigabit LAN card, and running Netgear’s  (Sorry commenteers!) Netgate’s pfSense routing software, the old machine has enough power to be complete overkill for the application.

The side benefit of this method is configurability. pfSense has a far more powerful set of options than most common routers. It’s config page also runs far more smoothly, too. There’s also the possibility to run all sorts of useful plugins, like router-level ad blockers and traffic monitoring utilities.

Overall, it’s a great way to repurpose a surplus machine and improve your network performance on the cheap. Others have tried similar builds, too. It has us contemplating the possibilities for our own networks at home!