SMT Part Counter Aims To Ease Taking Inventory

[Nick Poole] has an interesting idea for a new tool, one that has the simple goal of making accurate part counts of SMT reels as easy as pulling tape through a device. That device is the BeanCounter, an upcoming small handheld unit of his own design that counts parts as quickly as one can pull tape through a slot. The device is powered by a CR2032 cell and and works with 8 mm wide tapes up to 2 mm in height, which [Nick] says covers most 0805 or smaller sized parts, as well as things like SOT-23 transistors.

Why would one want to make such a task easier? Two compelling reasons for such a tool include: taking inventory of parts on partial reels or cut tape, and creating segments that contain a known number of parts.

The first is handy for obvious reasons, and the second is useful for things like creating kits. In fact, the usefulness of this tool for creating tape segments of fixed length is perhaps not obvious to anyone who hasn’t done it by hand. Sure, one can measure SMT tape with a ruler or a reference mark to yield a segment containing a fixed number of parts, but that involves a lot of handling and doesn’t scale up very well. In fact, the hassle of cutting tape segments accurately and repeatedly is a common pain point, so making the job easier has value.

If you looked at the photos and suspected that the big, 7-segment numeric display is done with clever PCB fabrication options (making segments by shining LEDs through PCB layers, a trick we always like to see) you’re not alone. After all, [Nick] has a lot of experience in getting clever with board fabrication, and eagle-eyed readers may even suspect that the reset and setup buttons on the edge of the tool are created by using flex PCB segments as switches. Want the nitty-gritty details? Visit the GitHub repository for the project and see it all for yourself at the CAD level.

Paper Tape Reader Self-calibrates, Speaks USB

Input devices consisting of optical readers for punched paper tape have been around since the earliest days of computing, so why stop now? [Jürgen]’s Paper Tape Reader project connects to any modern computer over USB, acting like a serial communications device. Thanks to the device’s automatic calibration, it works with a variety of paper materials. As for reading speed, it’s pretty much only limited to how fast one can pull tape through without damaging it.

Stacked 1.6 mm PCBs act as an enclosure, of sorts.

While [Jürgen]’s device uses LEDs and phototransistors to detect the presence or absence of punched holes, it doesn’t rely on hardware calibration. Instead, the device takes analog readings of each phototransistor, and uses software-adjusted thresholds to differentiate ones from zeros. This allows it to easily deal with a wide variety of tape types and colors, even working with translucent materials. Reading 500 characters per second isn’t a problem if the device has had a chance to calibrate.

Interested in making your own? The build section of the project has all the design files; it uses only through-hole components, and since the device is constructed from a stack of 1.6 mm thick PCBs, there’s no separate enclosure needed.

Paper tape and readers have a certain charm to them. Cyphercon 4.0 badges featured tape readers, and we’ve even seen the unusual approach of encoding an I2C byte stream directly onto tape.

This DIY UPDI Programmer Is Nice And Cheap

[Daumemo] likes experimenting with DIY electronics, and like many people, eventually ran across an AVR microcontroller with a Unified Program and Debug Interface (UPDI). One option is of course to purchase an UPDI programmer, but an even better solution was to make a DIY USB version from nice, cheap parts.

Programming an Attiny404 over the UPDI interface.

UPDI is an interface for external programming and on-chip debugging of microcontrollers, and [Daumemo]’s solution is based on the jtag2updi project. It combines an Arduino Nano (in this case, a clone) with a single resistor, a single capacitor, and a six pin angled header (with a cleverly bent pin) to enable programming UPDI devices over a USB connection. [Daumemo] is happy to report that the device works just fine in both Microchip Studio with AVRDUDE, or PlatformIO.

Is an Arduino Nano a bit overpowered in this role? Maybe, but the price is certainly right. There’s no need for a custom PCB either, since everything can be soldered direct to the Nano board. A matching 3D printed enclosure is about all that’s needed to make a robust and reliable DIY USB UPDI programmer out of a handful of parts, and that sounds good to us.

On the other hand, if you do find yourself making custom PCBs, you may be interested in another of [Daumemo]’s DIY projects: a printable structure to turn a rotary tool into a PCB drill press.

Camera held in hand

Review: Vizy Linux-Powered AI Camera

Vizy is a Linux-based “AI camera” based on the Raspberry Pi 4 that uses machine learning and machine vision to pull off some neat tricks, and has a design centered around hackability. I found it ridiculously simple to get up and running, and it was just as easy to make changes of my own, and start getting ideas.

Person and cat with machine-generated tags identifying them
Out of the box, Vizy is only a couple lines of Python away from being a functional Cat Detector project.

I was running pre-installed examples written in Python within minutes, and editing that very same code in about 30 seconds more. Even better, I did it all without installing a development environment, or even leaving my web browser, for that matter. I have to say, it made for a very hacker-friendly experience.

Vizy comes from the folks at Charmed Labs; this isn’t their first stab at smart cameras, and it shows. They also created the Pixy and Pixy 2 cameras, of which I happen to own several. I have always devoured anything that makes machine vision more accessible and easier to integrate into projects, so when Charmed Labs kindly offered to send me one of their newest devices, I was eager to see what was new.

I found Vizy to be a highly-polished platform with a number of truly useful hardware and software features, and a focus on accessibility and ease of use that I really hope to see more of in future embedded products. Let’s take a closer look.

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Amazing “Connect Fore!” Robot Challenges Your Putting Practice

We’ve just come across [Bithead]’s amazing, robotically-automated mashup of miniature golf and Connect Four, which also includes an AI opponent who pulls no punches in its drive to win. Connect Fore! celebrates Scotland — the birthplace of golf, after all — and looks absolutely fantastic.

Scotty the AI opponent uses this robotic turret to make their moves in a game of Connect Fore!

The way it works is this: players take turns putting colored balls into one of seven different holes at the far end of the table. Each hole feeds to a clear tube — visible in the middle of the table — which represent each of the columns in a game of Connect Four.

Each player attempts to stack balls in such a way that they create an unbroken line of four in their color, either horizontally, vertically, or diagonally. In a one-player game, a human player faces off against “Scotty”, the computer program that chooses its moves with intelligence and fires balls from a robotic turret.

[Bithead] started this project as a learning experience, and being such a complex project, the write-up is extensive. We really recommend reading through the whole thing if you are at all interested in what goes into making such a project work.

What’s particularly interesting is all of the ways in which things nearly worked, or needed nudging or fine adjustment. One might think that reliably getting a ball to enter a hole and roll down a PVC tube wouldn’t be a particularly finicky task, but it turns out that all kinds of things can go wrong.

Even finding the right play surface was a challenge. [Bithead]’s first purchase from Amazon was a total waste: it looked bad, smelled bad, and balls didn’t roll well on it. There are high-quality artificial turfs out there, but the good stuff gets shockingly expensive, and such a small project pretty much pigeonholes one as a nuisance customer when it comes to vendors. The challenges [Bithead] overcame serve as a reminder to keep the 80/20 rule (or Pareto principle) in mind when estimating what will get a project to the finish line.

Right under the page break below is a brief video tour of the completed table, and after that, you can watch a game in action as [Bithead] faces off against Scotty the AI. Curious about the inner workings? The last video has some build details that fill in a few blanks from the write-up.

We’ve seen an automated Chess table before, but this is an entirely other, utterly fantastic level of work.
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Best Ways To Make PCB Breakaway Tabs, Revealed

Most of us are familiar with the concept of producing PCBs in a panel, and snapping them apart afterwards. V-grooves that go most of the way through a PCB are one way to go about this, but a line of perforations along which to snap a tab is another. But what’s the best size and spacing of holes to use? Sparkfun’s [Nick Poole] spent some $400 on PCBs to get some solid answers by snapping each of them apart, and judging the results.

The nice thing about creating a perforation line (or “mouse bites”) is that drill hits are a very normal thing in PCB production, which makes creating this kind of breakaway tab a very straightforward and flexible method. However, it can be tricky to get results that are just right. Too sturdy, and breaking apart is a hassle. Too weak, and the board may break or twist before its time. On top of that, edges must also break cleanly. We’ve covered panelizing PCBs in this way before, but this is the first time we’ve seen someone seriously look into how to create optimal breakaway tabs.

Placing holes tangent to the board edge (as shown above) isn’t the prettiest, but keeps PCB edges free from protrusions. This is best for boards that are rail-mounted, or have tight enclosures.

Data on designing mouse bites was sparse and a bit inconsistent, so [Nick] decided to figure it out empirically and share the results. The full details are available in Building a Better Mousebite (PDF download) but the essence of the recommendations are: 0.015″ unplated holes, spaced 0.025″ apart (center-to-center), tabs a maximum of 0.118″ wide (so as to be compatible with depanelizing tools), and holes that extend into the corners of the breakaway tab to avoid sharp edges. Holes should be placed slightly differently depending on whether one wishes to optimize the cosmetic appearance versus the physical smoothness of the board edge, but those numbers are the core of the guidelines.

To fine tune, [Nick] suggests increasing the spacing between holes to add strength, or just adding additional tabs. What about thickness of PCB? [Nick] tested boards both 0.8 mm and 1.6 mm thick, and while different amounts of torque were needed to snap the boards apart, things still worked as expected regardless of PCB thickness.

When it comes down to it, the best numbers will ultimately be the ones that your process or fab house can most efficiently handle, but [Nick]’s numbers should not steer anyone wrong, and it’s fantastic to see this kind of work go into refining such a common PCB feature.

Enjoy This Animatronic Eyeball’s Smooth Moves

[Enza3D] shows off a surprisingly compact articulated animatronic eyeball that can be intuitively controlled with a Wii nunchuk controller. The design uses 3D printed parts and some tiny servos, and all of the necessary electronics can be easily purchased online. The mechanical design of the eye is very impressive, and [Enza3D] walks through several different versions of the design, the end result of which is a tidy little assembly that would fit nicely into masks, costumes, or other projects.

A Wii nunchuk is ideal for manual control of such a device, thanks to its ergonomic design and ease of interface (the nunchuk communicates over I2C, which is easily within the reach of even most modest of microcontrollers.) Of course, since driving servos is also almost trivial nowadays, it doesn’t look like working this into an automated project would pose much of a challenge.

The eyeball looks great, but if you want to try for yourself, accessing the design files and code will set you back $10 which might look attractive if an eye like this is the missing link for a project.

On the other hand, enjoying the video (embedded below) and getting ideas from [Enza3D]’s design notes will only cost you a few minutes.

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