Building A Vector Graphics Machine From Scratch Including The CRT

Over the years we’ve seen quite a few projects involving vector graphics, but the spaceship game created by [Mark Aren] especially caught our eye because in it he has tackled building a vector display from scratch rather than simply using a ready-made one such as an oscilloscope. As if the vector game itself wasn’t interesting enough, the process of designing the electronics required to drive a CRT is something that might have been commonplace decades ago but which few electronics enthusiasts in 2020 will have seen.

In his write-up he goes into detail on the path that took him to his component choices, and given the unusual nature of the design for 2020 it;s a fascinating opportunity to see the job done with components that would have been unheard of in the 1950s or 1960s. He eventually settled on a high voltage long-tailed pair of bipolar transistors, driven by a single op-amp to provide the differential signal required by the deflection electrodes. The mix of old and new also required a custom-fabricated socket for the CRT. On the game side meanwhile, an ATmega328 does the heavy lifting, through a DAC. He goes into some detail on DAC selection, having found some chips gave significant distortion.

All in all this is an impressive project from all angles, and we’re bowled over by it. Of course, if you fancy a play with vector graphics, perhaps there’s a simpler way.

This Debug Connector Brings Your Issues To The Edge

Given an unknown PCBA with an ARM processor, odds are good that it will have either the standard 10 pin 0.05″ or 20 pin 0.1″ debug connector. This uncommon commonality is a boon for an exploring hacker, but when designing a board such headers require board space in the design and more components to be installed to plug in. The literally-named Debug Edge standard is a new libre attempt to remedy this inconvenience.

The name “Debug Edge” says it all. It’s a debug, edge connector. A connector for the edge of a PCBA to break out debug signals. Card edge connectors are nothing new but they typically either slot one PCBA perpendicularly into another (as in a PCI card) or hold them in parallel (as in a mini PCIe card or an m.2 SSD). The DebugEdge connector is more like a PCBA butt splice.

It makes use of a specific family of AVX open ended card edge connectors designed to splice together long rectangular PCBAs used for lighting end to end. These are available in single quantities starting as low as $0.85 (part number for the design shown here is 009159010061916). The vision of the DebugEdge standard is that this connector is exposed along the edge of the target device, then “spliced” into the debug connector for target power and debug.

Right now the DebugEdge exists primarily as a standard, a set of KiCAD footprints, and prototype adapter boards on OSHPark (debugger side, target side). A device making use of it would integrate the target side and the developer would use the debugger side to connect. The standard specifies 4, 6, 8, and 10 pin varieties (mapping to sizes of available connector, the ‘010’ in the number above specifies pincount) offering increasing levels of connectivity up to a complete 1:1 mapping of the standard 10 pin ARM connector. Keep in mind the connectors are double sided, so the 4 pin version is a miniscule 4mm x 4.5mm! We’re excited to see that worm its way into a tiny project or two.

We’ve seen plenty of part-free debug and programming connectors before. Have a favorite? Let us know in the comments!

SMD Challenge Extreme Edition Gets Our Flux Flowing

Skills challenges have become a fun way to facilitate friendly competition amongst anyone who appreciates a fine solder joint. If you’ve seen any Supercon / Remoticon coverage there’s surely been a mention of the infamous soldering skills challenge, where competitors test their mettle against surface mount components sized to be challenging but fair. What if there was a less friendly SMD challenge designed to make you hold your breath lest you blow the components away? Well now there is, the SMD Challenge Extreme Edition by friend-of-the-Hackaday and winner of the 2019 Supercon soldering challenge [Freddie].

When assembled the SMD Extreme Edition uses a 555 timer and a 74HC4017 decade counter to light a ring of 10 LEDs lights around its perimeter, powered by a coin cell. However the  Extreme Edition deviates from the typical SMD Challenge format. Instead of ramping up in difficulty with ever-shrinking components, the Extreme Edition only has one size: torturous. See those gray blobs in the title image? Those are grains of rice.

The Extreme Edition’s 0201-sized LEDs aren’t the absolute smallest components around, but to minimize enjoyment all passives are 01005. (Check out the SMD Challange Misery Edition for even 01005 LED action.)

The Extreme Edition has other tricks up its sleeve, too. That 555 may be venerable in age, but this version is in an iron-frustrating 1.41 x 1.43 mm BGA package, which pairs nicely with that decade counter in 2.5 mm x 3.5 mm QFN.

Despite the wordwide pandemic locking down travel and conferences, a few brave challengers have already taken up their iron and succeeded at Extreme SMD. Want to see it in action? Check out the original Tweets after the break.

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Visualizing Magnetic Memory With Core 64

For the vast majority of us, computer memory is a somewhat abstract idea. Whether you’re declaring a variable in Python or setting a register in Verilog, the data goes — somewhere — and the rest really isn’t your problem. You may have deliberately chosen the exact address to write to, but its not like you can glance at a stick of RAM and see the data. And you almost certainly can’t rewrite it by hand. (If you can do either of those things, let us know.)

These limitations must have bothered [Andy Geppert], because he set out to bring computer memory into the tangible (or at least, visible) world with his interactive memory badge Core 64. [Andy] has gone through a few different iterations, but essentially Core 64 is an 8×8 grid of woven core memory, which stores each bit via magnetic polarization, with a field of LEDs behind it that allow you to visualize what’s stored. The real beauty of this setup is that it it can be used to display 64 pixel graphics. Better yet — a bit can be rewritten by introducing a magnetic field at the wire junction. In other words, throw a magnet on a stick into the mix and you have yourself a tiny drawing tablet!

This isn’t the first time we’ve seen cool experiments with core memory, and not even the first time we’ve seen [Andy] use it to make something awesome, but it really illuminates how the technology works. Being able to not only see memory being written but to manually write to it makes it all so much realer, somehow.

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Door Mutes Microphone To Prevent Remote Learning Humiliation

In a kind of reverse twist on the doorbell, [TheStaticTurtle] whipped up a system to mute his computer’s microphone whenever someone opens the door to his room. He lives in France, where the government announced a strict lockdown last Friday. Like many university students around the world these days, he is now forced to take online classes. Even though he has his own room, occasionally someone will barge in and announce something, often to [TheStaticTurtle]’s embarrassment.  When his classmates suddenly heard “Do you want some pie?” the other day, it was the last straw.

His first decision was to sense the door opening with a magnet and sensor, which he stuck to the door and frame with hot glue. He then ran a long cable to his desk, where it connected to an ATTiny 85 with a DigiSpark boot-loader. He wrote firmware to simulate special key combinations, which were then registered with his audio routing software Voicemeeter Potato. We presume he isn’t using an external mic, in which case muting might have been easier to accomplish with a hardware switch. All in all, this is a pretty clever and timely hack. Should you be in a similar predicament and want to try this out, he’s published the source code on GitHub.

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How To Improve A Smart Motor? Make It Bigger!

Brushless motors can offer impressive torque-to-size ratios, and when combined with complex drive control and sensor feedback, exciting things become possible that expand the usual ideas of what motors can accomplish. For example, to use a DC motor in a robot leg, one might expect to need a gearbox, a motor driver, plus an encoder for position sensing. If smooth, organic motion is desired, some sort of compliant mechanical design would be involved as well. But motors like the IQ Vertiq 6806 offered by [IQ Motion Control] challenge those assumptions. By combining a high-torque brushless DC motor, advanced controller, and position sensing into an integrated device, things like improved drone performance and direct-drive robotic legs like those of the Mini Cheetah become possible.

IQ Vertiq 6806 brushless DC motor with integrated controller, driver, and position sensing.

First, the bad news: these are not cheap motors. The IQ Vertiq 6806 costs $399 USD each through the Crowd Supply pre-order ($1499 for four), but they aren’t overpriced for what they are. The cost compares favorably with other motors and controllers of the same class. A little further than halfway down the Crowd Supply page, [IQ Motion Control] makes a pretty good case for itself by comparing features with other solutions. Still, these are not likely to be anyone’s weekend impulse purchase.

So how do these smart motors work? They have two basic operating modes: Speed and Position, each of which requires different firmware, and which one to use depends on the intended application.

The “Speed” firmware is designed with driving propeller loads in mind, and works a lot like any other brushless DC motor with an ESC (electronic speed control) on something like a drone or other UAV. But while the unit can be given throttle or speed control signals like any other motor, it can also do things like accept commands in terms of thrust. In other words, an aircraft’s flight controller can communicate to motors directly in thrust units, instead of a speed control signal whose actual effect is subject to variances like motor voltage level.

The “Position” mode has the motor function like a servo with adjustable torque, which is perfect for direct drive applications like robotic legs. The position sensing also allows for a few neat tricks, like the ability to use the motors as inputs. Embedded below are two short videos showcasing both of these features, so check them out.

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Bespoke Storage Technologies: The Alphabet Soup Found In Modern Hard Drives And Beyond

It seems like just yesterday (maybe for some of you it was) we were installing Windows 3.1 off floppy drives onto a 256 MB hard drive, but hard drives have since gotten a lot bigger and a lot more complicated, and there are a lot more options than spinning platters.

The explosion of storage options is the result of addressing a variety of niches of use. The typical torrenter downloads a file, which is written once but read many times. For some people a drive is used as a backup that’s stored elsewhere and left unpowered. For others it is a server frequently reading and writing data like logs or swap files. In all cases it’s physics that sets the limits of what storage media can do; if you choose wisely for your use case you’ll get the bet performance.

The jargon in this realm is daunting: superparamagnetic limit, LMR, PMR, CMR, SMR, HAMR, MAMR, EAMR, XAMR, and QLC to name the most common. Let’s take a look at how we got here, and how the past and present of persistent storage have expanded what the word hard drive actually means and what is found under the hood.

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