Arduino Takes Control Of Dead Business Card Cutter

September 10, 2020 by Tom Nardi 13 Comments

It’s a common enough situation, that when an older piece of equipment dies, and nobody wants to spend the money to repair it. Why fix the old one, when the newer version with all the latest bells and whistles isn’t much more expensive? We all understand the decision from a business standpoint, but as hackers, it always feels a bit wrong.

Which is exactly why [tommycoolman] decided to rebuild the office’s recently deceased Duplo CC-330 heavy duty business card cutter. It sounds like nobody really knows what happened to the machine in the first place, but since the majority of the internals were cooked, some kind of power surge seems likely. Whatever the reason, almost none of the original electronics were reused. From the buttons on the front panel to the motor drivers, everything has been implemented from scratch.

An Arduino Mega 2560 clone is used to control four TB6600 stepper motor drivers, with a common OLED display module installed where the original display went. The keypad next to the screen has been replaced with 10 arcade-style buttons soldered to a scrap of perfboard, though in the end [tommycoolman] covers them with a very professional looking printed vinyl sheet. There’s also a 24 V power supply onboard, with the expected assortment of step up and step down converters necessary to feed the various electronics their intended voltages.

In the end, [tommycoolman] estimates it took about $200 and 30 hours of work to get the card cutter up and running again. The argument could be made that the value of his time needs to be factored into the repair bill as well, but even still, it sounds like a bargain to us; these machines have a four-figure price tag on them when new.

Stories like this one are important reminders of the all wondrous things you can find hiding in the trash. Any time a machine like this can be rescued from the junkyard, it’s an accomplishment worthy of praise in our book.

ISS Ham Radio Repeater

September 10, 2020 by Al Williams 28 Comments

There is a long history of spacecraft carrying ham radio gear, as the Space Shuttle, Mir, and the ISS have all had hams aboard with gear capable of talking to the Earth. However, this month, the ISS started operating an FM repeater that isn’t too dissimilar from a terrestrial repeater. You can see [TechMinds] video on the repeater, below.

The repeater has a 2 meter uplink and a 70 centimeter downlink. While you can use a garden variety dual-band ham transceiver to use the repeater, you’ll probably need a special antenna along with special operating techniques.

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Reverse Engineering A Module From A Vacuum Tube Computer

September 10, 2020 by Dan Maloney 32 Comments

It’s best to admit upfront that vacuum tubes can be baffling to some of the younger generation of engineers. Yes, we get how electron flow from cathode to anode can be controlled with a grid, and how that can be used to amplify and control current. But there are still some things that just don’t always to click when looking at a schematic for a tube circuit. Maybe we just grew up at the wrong time.

Someone who’s clearly not old enough to have ridden the first wave of electronics but still seems to have mastered the concepts of thermionic emission is [Usagi Electric], who has been doing some great work on reverse engineering modules from old vacuum tube computers. The video below focuses on a two-tube pluggable module from an IBM 650, a machine that dates clear back to 1954. The eBay find was nothing more than two tube sockets and a pair of resistors joined to a plug by a hoop of metal. With almost nothing to go on, [Usagi] was still able to figure out what tubes would have gone in the sockets — the nine-pin socket was a big clue — and determine that the module was likely a dual NAND gate. To test his theory, [Usagi] took some liberties with the original voltages used by IBM and built a breakout PCB. It’s an interesting mix of technologies, but he was able to walk through the truth table and confirm that his module is a dual NAND gate.

The video is a bit long but it’s chock full of tidbits that really help clear up how tubes work. Along with some help from this article about how triodes work, this will put you on the path to thermionic enlightenment.

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Surfboard LED Strips Light Up The Waves

September 10, 2020 by Lewin Day 10 Comments

Surfing is an activity predominantly enjoyed during the day, primarily for reasons of warmth and water safety. Of course, if you prefer to carve the waves at night, you might enjoy the latest project from [Moritz Sivers] – a surfboard kitted out with motion-reactive LEDs.

The build consists of a regular surfboard, with a channel cut around the perimeter into which WS2812B LED strips are glued. Powered by a lithium rechargable battery, commands are given by an Arduino Nano hooked up to a MPU6050 3-axis gyroscope. This allows the Arduino to change the light patterns based on the movement of the board. Left and right turns, pumping the board, and surfing down a wave all come with their own animations.

It’s a fun twist on night surfing, and makes it easier to spot a downed surfer, too. It’s a build we expect to see recreated in a high-end 4K surf film before the year is out. Of course, if you just need to know if the conditions are right before you head out, this surf weather station might be just the build for you. Video after the break. Continue reading “Surfboard LED Strips Light Up The Waves” →

Eye-Catching And Crumb-Suspending

September 10, 2020 by Brian McEvoy 5 Comments

Printed circuit boards used to be green or tan, and invariably hidden. Now, they can be artful, structural, and like electronic convention badges, they are the entire project. In this vein, we find Open LEV, a horseshoe-shaped desktop bauble bristling with analog circuitry supporting an acoustic levitator. [John Loefler] is a mechanical engineer manager at a college 3D printing lab in Florida, so of course, he needs to have the nerdiest stuff on his workspace. Instead of resorting to a microcontroller, he filled out a parts list with analog components. We have to assume that the rest of his time went into making his PCB show-room ready. Parts of the silkscreen layer are functional too. If you look closely at where the ultrasonic transducers (silver cylinders) connect, there are depth gauges to aid positioning. Now that’s clever.

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The O-Bahn Busway – Obscure Transit For The Masses

September 10, 2020 by Lewin Day 77 Comments

Around the world, governments and city planners have long struggled with the issue of transport. Getting people where they need to be in a timely fashion is key to making a city a comfortable, attractive place to live. As far as public transport is concerned, this typically consists of buses on the roads, and trams and trains on rails.

Down in the city of Adelaide, Australia, things get a little muddled, however. Nestled in a river valley lies a special transportation network known as the O-Bahn, where buses ride on concrete rails and the drivers can even take their hands off the wheel. The system remains a rarity worldwide, and was spawned by a perfect storm of conflicting requirements.

A Child of Circumstance

In the 1970s, the South Australian government found itself backed into a corner. Facing a booming population in the north-eastern suburbs, new transport links with greater capacity were needed to get people to the central business district. Original plans from the 1960s had called for more freeways to be built all over the city to solve the problem. In the face of stiff public opposition, legislation was passed in 1970 blocking the construction of any new freeways for a full decade, forcing the government to consider alternatives.

O-Bahn buses passing at speed near Stephens Terrace. Buses formerly reached speeds up to 100 km/h on the network; this was dropped to 85 km/h in 2012, adding 20 seconds to the average run. Credit: Lewin Day

Despite plans being shelved, a corridor of land stretching from the city to the north-east had already been acquired for freeway construction. This was retained, and studies were commissioned to determine the best transportation solution to suit the needs of the area. The “North East Adelaide Public Transport Review” suggested light-rail or a busway would be the best solution.

Initial plans were proposed to link the north-east with a light-rail tramway that would connect with the existing tramline from the city proper to Glenelg in the west. However, the City of Adelaide protested the plan, believing that extending the existing tramline to the east would damage the city’s carefully planned structure. Plans were made to rectify this by running part of the line underground, massively increasing costs, and the proposal was shelved.

It was at this time, the guided busway in Essen, Germany came to the attention of the state government. Aiming to help reduce congestion by allowing buses to share tram tunnels, it began as a demonstration which later developed into the Spurbus network. The system offered lower cost and higher flexibility than light rail, and avoided the need to carve up the city to hook in to the existing light rail network. Had Adelaide laid out its existing heavy or light rail networks differently, the O-Bahn might not have gotten a look in. However, back in the early 1980s, it was an easy solution in a sea of difficult choices.

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Garbage Can Takes Itself Out

September 10, 2020 by Bryan Cockfield 12 Comments

Home automation is a fine goal but typically remains confined to lights, blinds, and other things that are relatively stationary and/or electrical in nature. There is a challenge there to be certain, but to really step up your home automation game you’ll need to think outside the box. This automated garbage can that can take itself out, for example, has all the home automation street cred you’d ever need.

The garbage can moves itself by means of a scooter wheel which has a hub motor inside and is powered by a lithium battery, but the real genius of this project is the electronics controlling everything. A Raspberry Pi Zero W is at the center of the build which controls the motor via a driver board and also receives instructions on when to wheel the garbage can out to the curb from an Nvidia Jetson board. That board is needed because the creator, [Ahad Cove], didn’t want to be bothered to tell his garbage can to take itself out or even schedule it. He instead used machine learning to detect when the garbage truck was headed down the street and instruct the garbage can to roll itself out then.

The only other thing to tie this build together was to get the garage door to open automatically for the garbage can. Luckily, [Ahad]’s garage door opener was already equipped with WiFi and had an available app, unbeknownst to him, which made this a surprisingly easy part of the build. If you have a more rudimentary garage door opener, though, there are plenty of options available to get it on the internets.

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