Simon Game Is A Story Of Rushed Deadlines And Holiday Cheer

April 13, 2019 by 1 Comment

Sometimes the Christmas season can feel like a holiday all about spending money to demonstrate your love for others. Many a maker has attempted to subvert these commercialistic overtones by giving handmade presents to friends and loved ones. [APA] is no exception, and has shared their story of producing a simple Simon game during the holidays.

The circuit is nothing wild – an ATtiny85 microcontroller interfaces a handful of buttons and LEDs to handle the basic Simon gameplay. The real value is in [APA]’s retelling of the development process. It’s an accurate recounting that makes us relive some of our own follies of early projects. There’s the confusion between SMD and through hole versions of the same part, forgotten pull up resistors, as well as hours lost trying to figure out why a chip won’t write, only to learn the bootloader hasn’t been burned yet.

In the end, [APA] was able to push through a rush order and deliver the gifts on time, despite the many pitfalls along the way. The final game provided some laughs around the dinner table at Christmas, so we’d say the mission was definitely accomplished.

We’ve seen similar work before, too – like this tiny Simon game on an ATtiny13.

These Wire Strippers Are Made From PCBs

April 13, 2019 by 12 Comments

The rise in cheap PCB fabrication has made old-school prototyping methods such as wire wrapping somewhat passé, but it still has its place. And if you’re going to wire wrap, you’re going to want a quick and easy way to strip that fine Kynar-insulated wire. So why not use PCB material to make this handy wire-wrapping wire stripper?

The tool that [danielrp] built is pretty simple – just a pair of razor blades held together so as to form a narrow slot to cut insulation while leaving the conductor untouched. The body of the tool is formed of two PCBs, between which the blades are sandwiched. [danielrp] designed the outline of the PCBs in DraftSight, then exported a DXF into EAGLE to make the Gerbers. The fabricated boards needed a little post-processing, including tapping the holes on one side to accept the screws that hold the tool together. We were surprised that FR4 took the threads at all, but it seems to work for this low-torque application. The disposable snap-type blades were sandwiched between the PCBs and the gap between them adjusted for nick-free stripping. The video below shows the design and build process.

We always appreciate homemade tools, and the fact that you can get a stack of PCBs for almost nothing makes us wonder what else we could use them for. We recently saw them used in a unique word clock, and even turned into a folding circuit sculpture.

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Remanufacturing A Rotary Airplane Engine

April 13, 2019 by 66 Comments

If someone tells you they have seen a rotary engine, the chances are that you will immediately think of a Wankel engine, as you might find in some of the more exotic Mazda sports cars. But there is another rotary engine that has a prior claim to the name, and it can be found as the power unit for many early-twentieth-century aircraft. In these rotary engines the cylinders are arranged radially around a stationary crankshaft, and it is the engine itself that rotates. They have the advantage of extreme simplicity, smooth power, and a low parts count, at the expense of total loss lubrication, a relatively large rotating mass, and some difficulty in controlling their power. These rotary engines were largely obsolete by the 1920s, but  recent upsurge of interest in WW1-era aircraft has led to the creation of a small demand for them. New Zealand based Classic Aero Machining Service have stepped in to fill that gap and are remanufacturing the Gnome radial engine, the most numerous design of that era.

For anyone with an interest in internal combustion engines, the Gnome is a fascinating study. It’s a nine-cylinder design that runs a four-stroke Otto cycle, but instead of the two or more valves you might be familiar with from your motor vehicle it has only a single valve. The so-called Monosoupape design uses its valve for both fuel and exhaust, opening it on the inlet stroke as well as the exhaust stroke. The simplicity of a single valve and no carburetor is thus offset by a difficulty in varying its power , so rotary engines would frequently reduce the number of firing cylinders in lieu of throttling back.

The CAMS Gnome is a faithful copy of the original, but with modern metallurgy and the addition of an electronic ignition system. The original castor oil is still used — it seems classic aviation buffs like the smell — but becuase it is notorious for leaving sticky deposits in the engine they are evaluating modern alternatives. They have some technical details on their website, and there’s a good chance you my hear one of their engines one day at an air show near you.

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It’s (Almost) Two Keytars In One!

April 13, 2019 by 4 Comments

All the best retro-1980s chiptune acts should possess a keytar. It’s the Law, or something. [Theremin Hero] has reminded us of this with a new video we’ve shown below featuring an instrument he had a part in creating alongside [Sam Wray] and [Siddharth Vadgama] a few years ago. The Blade is a 3D-printed keytar featuring two Guitar Hero necks and an integrated pair of Game Boys to provide the sound from the authentic silicon.

To describe it in those terms though is to miss a wealth of other components and featured. The keyboard itself is from a Rock Band keytar which feeds MIDI to a Raspberry Pi running PD Extended that handles all the button press mappings. An Arduino Mega performs the same task for the two Guitar Hero necks. Midi from the various sources is processed by an Arduino Boy which then feeds the Game Boys that make the sounds. Oh – and there’s a Leap Motion 3D motion controller in the mix as well, though that doesn’t seem to be used directly in the chiptune synth functionality.

We’ve had a few keytars here over the years, but this one makes us think of the Commodore 64 instrument created by [Jeri Ellsworth].

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Rad-Hard ARM Microcontrollers, Because Ceramic Components Are Just Cooler

April 13, 2019 by 57 Comments

If you’re building a cubesat, great, just grab a microcontroller off the shelf, you probably don’t need to worry about radiation hardening. If you’re building an experiment for the ISS, just use any old microcontroller. Deep space? That’s a little harder, and you might need to look into radiation tolerant and radiation hardened microcontrollers. Microchip has just announced the release of two micros that meet this spec, in both radiation-tolerant and radiation-hardened varieties.

The new devices are the SAMV71Q21RT (radiation-tolerant) and the SAMRH71 (rad-hard), both ARM Cortex-M7 chips running at around 300 MHz with enough RAM to do pretty much anything you would want to do with a microcontroller. Peripherals include CAN-FD and Ethernet-AVB, analog front-end controllers, and the usual support for I2C, SPI, and other standards. This chip does it in space, and comes in a ceramic quad flat package with gold lead frames. These are beautiful devices.

Microchip has an incredible number of space-rated, rad-hard hardware; this is mostly due to their acquisition of Atmel a few years ago, and yes, it absolutely is possible to build a rad-hard Arduino Mega using the chip, space rated.

Of course, there are very, very, very few people who would actually ever need a rad-hard microcontroller; I would honestly expect this to be relevant to only one or two people reading this, and they too probably got the press release. If you’ve ever wanted to build something that goes to space, and you’d like to over-engineer everything about it, you now have the option for an ARM Cortex-M7.

Pick And Place For Toys

April 13, 2019 by 6 Comments

Toys are great for keeping the kids amused at play time, but oftentimes its difficult to get them to understand the importance of tidying up after themselves. It would naturally be ideal to have some manner of robot to help in this regard, and [Paco Garcia] might just be leading the charge in this area.

[Paco]’s project involves combining a robotic arm with computer vision tools in order to allow it to pick and place small objects – in this example, toys. The robot arm is of a gantry type, built on an aluminium frame with 3D printed components. The computer vision side of things is handled by a Raspberry Pi, fitted with the standard camera and running OpenCV software for object recognition. This then passes commands to an Arduino which runs the stepper motors controlling the arm.

[Paco] notes that the hardest part of the build was learning how to generate real-world coordinates from a single camera feed in OpenCV. With that mastered, the rest of the dominoes began to fall. With trigonometry and kinematics knowledge in hand, the robot has grown capable of reliably picking and placing small objects across its range of motion. Future work aims to improve the robot’s abilities to rotate and otherwise manipulate its end effector for more versatility.

Naturally, we typically see pick and place machines used for PCB production – and this build is no exception. Video after the break.

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Electronics On Ice

April 12, 2019 by 6 Comments

We see all manner of electronics enclosures pass through these hallowed pages. Lasercut wooden builds with fancy kerf bending, expertly prepared acrylic boxes, and even the occasional device cast in concrete. [Mike Kohn] decided that all of these were too permanent, however, and chose a different material – ice.

[Mike] shares the ups and downs of his experiments with electronics and frozen water. Initial tests with a circuit sealed in DAP Ultra Clear were largely successful.  A tilt sensor was installed to allow the batteries to remain undrained during the freezing process, and once freed after a few hours of thawing, the circuit was operational. Later builds required some more work – the RC car in particular took a few attempts to avoid the mold leaking. The ice hands are a particular highlight, though – created with rubber gloves, these would be a remarkably spooky decoration come Halloween.

It’s a study in the techniques required to work with this ephemeral material, and there’s a few lessons to learn. Sealing electronics is good, and the best results are with simple circuits with a few LEDs that make everything glow nicely.

If you’re looking for other ideas, you could always create a frozen lens for photographical purposes. Video after the break.

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