Let KiCad And Python Make Your Coils

October 19, 2020 by Al Williams 16 Comments

We like to pretend that our circuits are as perfect as our schematics. But in truth, PCB traces have unwanted resistance, capacitance, and inductance. On the other hand, that means you can use those traces to build components. For example, it isn’t uncommon to see a very small value current sense resistor be nothing more than a long PC board trace. Using PC layers for decoupling capacitance and creating precise transmission lines are other examples. [IndoorGeek] takes us through his process of creating coils on the PCB using KiCad. To help, he used a Python script that works out the circles, something KiCAD has trouble with.

The idea is simple. A coil of wire has inductance even if it is a flat copper trace on a PCB. In this case, the coils are more for the electromagnetic properties, but the same idea applies if you wanted to build tuned circuits. The project took inspiration from FlexAR, an open-source flexible PCB magnet.

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Stomp Button, Receive Candy

October 19, 2020 by Kristina Panos 5 Comments

If there’s any holiday that is worth adjusting for strange times, it’s gotta be Halloween. Are you inclined to leave a bowl of candy on the porch to avoid the doorbell? If so, this is the perfect year to finally figure out some sort of metering apparatus so that greedy preteens are less likely to steal your stash in one sweep. There’s still time to make something fun like [Brankly]’s automatic candy dispenser, which we think ought to stick around for many years to come. Video is posted after the break.

Underneath that skeleton’s jack-o-lantern head is the heart of this build — an orange 5-gallon bucket that matches it perfectly. Simply step on the giant lighted arcade button, and the equally giant NEMA-23 stepper motor moves a 3D-printed turntable inside the bucket with the help of an Arduino Nano. This moves the candy toward the 3D-printed ramp and out the mouth of the jack-o-lantern, where it lands in a bowl that lights up when it hits the bottom thanks to a relay and a second Nano.

[Brankly] made clever use of IR break-beam switches, which sit underneath the two square holes in the ramp. Once candy passes over one of them, the turntable stops and rotates backward to move the candy where it can’t be reached.

Frankly, we love that [Brankly] reused the sound effects module that came with the jack-o-lantern. This build is totally open, and [Brankly] is even giving away 40 PCBs if you want to make your own. For now, you can check out the code and start printing the STLs.

If time is tight, build a spooky slide that puts six feet between you and the trick or treaters.

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PyBot Is A 3D Printed SCARA Arm For The Masses

October 19, 2020 by Tom Nardi 10 Comments

We’ve all seen videos of blisteringly fast SCARA arms working on assembly lines, and more than a few of us have fantasied about having that same kind of technology for the home shop. Unfortunately, while the prices for things like 3D printers and oscilloscopes have dropped lower than what many would have believed possible a decade ago, high-performance robotics are still too pricey for the home player.

Unless of course, you’re willing to build it yourself. The PyBot designed by [jjRobots] is an open source robotic arm that should be well within the means of the average hardware hacker. One could argue that this is a project made entirely possible by desktop 3D printing; as not only are most of the structural components printed, but most of the mechanical elements are common 3D printer parts. Smooth rods, linear bearings, lead screws, and NEMA 17 motors are all exceptionally cheap these days thanks to the innumerable 3D printer kits that make use of them.

A custom control board keeps the wiring tight.

Those who’ve researched similar projects might notice that the design of this arm has clearly been influenced by the Mostly Printed SCARA (MPSCARA). But while that robot was designed to carry an extruder and act as a 3D printer, [jjRobots] intends for the PyBot to be more of a general purpose platform. By default it features a simple gripper, but that can easily be changed out for whatever tool or gadget you have in mind.

In the base of the arm is a custom control board that combines an Arduino M0, an ESP8266, and a trio of stepper motor drivers. But if you wanted to build your own version from the parts bin, you could certainly wire up all the principle components manually. As the name implies, the PyBot is controlled by Python tools running on the computer, so it should be relatively easy to get this capable arm to do your bidding.

We’ve seen some impressive 3D printed robotic arms over the years, but the simplicity of the PyBot is particularly compelling. This looks like something that you could reasonably assemble and program over a weekend or two, and then put to work in your ad-hoc PPE factory.

Escape To An Alternate Reality Anywhere With Port-A-Vid

October 19, 2020 by Roger Cheng 26 Comments

There was a time when only the most expensive televisions could boast crystal clear pixels on a wall-mountable thin screen. What used to be novelty from “High Definition Flat Screen Televisions“ are now just “TV” available everywhere. So as a change of pace from our modern pixel perfection, [Emily Velasco] built the Port-A-Vid as a relic from another timeline.

The centerpiece of any aesthetically focused video project is obviously the screen, and a CRT would be the first choice for a retro theme. Unfortunately, small CRTs have recently become scarce, and a real glass picture tube would not fit within the available space anyhow. Instead, we’re actually looking at a modern LCD sitting behind a big lens to give it an old school appearance.

The lens, harvested from a rear-projection TV, was chosen because it was a good size to replace the dial of a vacuum gauge. This project enclosure started life as a Snap-On Tools MT425 but had become just another piece of broken equipment at a salvage yard. The bottom section, formerly a storage bin for hoses and adapters, is now home to the battery and electronics. All original markings on the hinged storage lid were removed and converted to the Port-A-Vid control panel.

Before: broken Snap-On MT425

After: An escape portal. Please stand by…

A single press of the big green button triggers a video to play, randomly chosen from a collection of content [Emily] curated to fit with the aesthetic. We may get a clip from an old educational film, or something shot with a composite video camera. If any computer graphics pop up, they will be primitive vector graphics. This is not the place to seek ultra high definition content.

As a final nod to common artifacts of electronics history, [Emily] wrote an user’s manual for the Port-A-Vid. Naturally it’s not a downloadable PDF, but a stack of paper stapled together. Each page written in the style of electronics manuals of yore, treated with the rough look of multiple generation photocopy rumpled with use.

If you have to ask “Why?” it is doubtful any explanation would suffice. This is a trait shared with many other eclectic projects from [Emily]. But if you are delighted by fantastical projects hailing from an imaginary past, [Emily] has also built an ASCII art cartridge for old parallel port printers.

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Does Your Phone Need A RAM Drive?

October 19, 2020 by Al Williams 73 Comments

Phones used to be phones. Then we got cordless phones which were part phone and part radio. Then we got cell phones. But with smartphones, we have a phone that is both a radio and a computer. Tiny battery operated computers are typically a bit anemic, but as technology marches forward, those tiny computers grew to the point that they outpace desktop machines from a few years ago. That means more and more phones are incorporating technology we used to reserve for desktop computers and servers. Case in point: Xiaomi now has a smartphone that sports a RAM drive. Is this really necessary?

While people like to say you can never be too rich or too thin, memory can never be too big or too fast. Unfortunately, that’s always been a zero-sum game. Fast memory tends to be lower-density while large capacity memory tends to be slower. The fastest common memory is static RAM, but that requires a lot of area on a chip per bit and also consumes a lot of power. That’s why most computers and devices use dynamic RAM for main storage. Since each bit is little more than a capacitor, the density is good and power requirements are reasonable. The downside? Internally, the memory needs a rewrite when read or periodically before the tiny capacitors discharge.

Although dynamic RAM density is high, flash memory still serves as the “disk drive” for most phones. It is dense, cheap, and — unlike RAM — holds data with no power. The downside is the interface to it is cumbersome and relatively slow despite new standards to improve throughput. There’s virtually no way the type of flash memory used in a typical phone will ever match the access speeds you can get with RAM.

So, are our phones held back by the speed of the flash? Are they calling out for a new paradigm that taps the speed of RAM whenever possible? Let’s unpack this issue.

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Exploring Animal Intelligence Hack Chat

October 19, 2020 by Dan Maloney 4 Comments

Join us on Wednesday, October 21st at noon Pacific for the Exploring Animal Intelligence Hack Chat with Hans Forsberg!

From our lofty perch atop the food chain it’s easy to make the assumption that we humans are the last word in intelligence. A quick glance at social media or a chat with a random stranger at the store should be enough to convince you that human intelligence isn’t all it’s cracked up to be, or at least that it’s not evenly distributed. But regardless, we are pretty smart, thanks to those big, powerful brains stuffed into our skulls.

We’re far from the only smart species on the planet, though. Fellow primates and other mammals clearly have intelligence, and we’ve seen amazingly complex behaviors from animals in just about every taxonomic rank. But it’s the birds who probably stuff the most functionality into their limited neural hardware, with tool use, including the ability to make new tools, being common, along with long-distance navigation, superb binocular vision, and of course the ability to rapidly maneuver in three-dimensions while flying.

Hans Forsberg has taken an interest in avian intelligence lately, and to explore just what’s possible he devised a fiendishly clever system to train his local magpie flock to clean up his yard, which he calls “BirdBox”. We recently wrote up his initial training attempts, which honestly bear a strong resemblance to training a machine learning algorithm, which is probably no small coincidence since his professional background is with neural networks. He has several years of work into his birds, and he’ll stop by the Hack Chat to talk about what goes into leveraging animal intelligence, what we can learn about our systems from it, and where BirdBox goes next.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, October 21 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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Motorized Magic Over HDMI

October 19, 2020 by Matthew Carlson 13 Comments

There is a certain warmth that seems to emanate from stereo receivers of the 70s, 80s, and 90s. Despite their large footprint and considerable heft, the soft glow of the indicator lights and solid kerthunk of switches provide a sense of coziness. When [Tom] recently swapped his receiver for a 1970s Pioneer SX-950, he found himself getting up from the couch to adjust the volume when watching TV far too often for his liking. Resolving to do something about it, he added some magic in the form of a motorized volume knob. One of the coolest tricks for stereos was to have a small motor attached to the volume knob so that it could turn the volume up or down via a remote.

The first obstacle came when [Tom] had to forgo the center tap on the potentiometer to get a motorized one. This meant the volume compensation feature would be disabled, which is but a small price to pay for convenience. After scouring the internet, he finally had the part in hand only to discover some troublesome capacitors in the way. The new pot had a rather large motor hanging off the back that the previous one didn’t have. Fortunately, there was a good bit of space between the PCB and the bottom of the chassis, so Tom was able to just flip the capacitors to the underside of the board and bend them on their sides.

The next problem to solve was how to change the volume remotely. IR was considered as well as optical cable control signals. What [Tom] did instead was to implement HDMI CEC (consumer electronics control). CEC was well documented and seemed simple to implement on an ATTINY4313 with the help of a half-H driver. The CEC protocol implemented by [Tom’s] TV seemed to be very sensitive to timing, so an external crystal was used to get more precise timing and additional handshaking was implemented to get the TV to accept the microcontroller as valid. A few fail-safes were added to make sure the motor didn’t burn out if something went wrong with the CEC protocol and a nice enclosure wrapped up the build quite nicely.

We’ve seen CEC implemented before on a PIC 18F87J50, but as a sender of CEC commands not a receiver. [Tom’s] code is available on GitHub and might prove useful if you’re looking to implement CEC on an AVR.

Thanks [Tom] for sending this one in!