3D Printable Kinematic Couplings, Ready To Use

Time may bring change, but kinematic couplings don’t. This handy kinematic couplings resource by [nickw] was for a design contest a few years ago, but what’s great is that it includes ready-to-use models intended for 3D printing, complete with a bill of materials (and McMaster-Carr part numbers) for hardware. The short document is well written and illustrated with assembly diagrams and concise, practical theory. The accompanying 3D models are ready to be copied and pasted anywhere one might find them useful.

What are kinematic couplings? They are a way to ensure that two parts physically connect, detach, and re-connect in a precise and repeatable way. The download has ready-to-use designs for both a Kelvin and Maxwell system kinematic coupling, and a more advanced design for an optomechanical mount like one would find in a laser system.

The download from Pinshape requires a free account, but the models and document are licensed under CC – Attribution and ready to use in designs (so long as the attribution part of the license is satisfied, of course.) Embedded below is a short video demonstrating the coupling using the Maxwell system. The Kelvin system is similar.

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Hands-On: Internet Of Batteries Quantum Badge Brings Badgelife Add-Ons The Power And Internet They Crave

Our friends in the Whiskey Pirates crew sent me the unofficial DEF CON badge they built this year. The Internet of Batteries QUANTUM provides power and connectivity to the all-important add-on badges of DC28. The front of the badge is absolutely gorgeous to the point I don’t really want to solder on my add-on headers and disrupt that aesthetic.

The gold-plated copper makes for a uniformed and reflective contrast to the red solder mask which occupies the majority of the front. Here we see the great attention to detail that [TrueControl] includes in his badges. The white stripe of silk screen separating the two colors is covered by some black detailing tape that looks much better than the white.

The antenna of the ESP32 module poking out the underside of the gold cover end of the badge gets its own rectangle of the holographic sticker material, the same as the sheet of stickers that was included in the box. Both decals are small details that make a huge difference to your eye.

The line of nine RGB LEDs have black bezels which goes along with the black stripe motif and underscores the typography of the badge name. These lights are hosted on a daughter board soldered to the underside of the badge with a slot for the LEDs to pass through. They are addressed in a 2×15 matrix that is scanned on the low side by the PSoC5 that drives the badge. This low-res image shows that daughter board before the lithium cell is placed.

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Hands-On: AND!XOR Unofficial DC28 Badge Embraces The Acrylic Stackup

Still hot from the solder party, a new AND!XOR badge just landed on my desk courtesy of the hacking crew that has been living the #badgelife for the past five years. Originally based on the Futurama character Bender, the design has morphed to the point that it’s no longer recognizable as a descendant of that belligerent robot. Instead we have a skeletal midget whose face is half covered by a gear-themed mask.

At first glance, you might not even notice the character design because you’re too distracted by the beautiful composure of the hardware. This year’s badge includes a double stack-up of acrylic on top of a red circuit-board. Anyone who has used acrylic bezels in a badge design can tell you the cost for material and laser cutting time is significant. In this case the overall aesthetic of the badge is based upon the look of the mirrored gold with the art detail laser etched into the back. It’s a unique bling without even turning the power on. Continue reading “Hands-On: AND!XOR Unofficial DC28 Badge Embraces The Acrylic Stackup”

Fewer Millimeters Make A Useful ESP32 Devboard

Sometimes the most useful hacks aren’t the flashiest, they’re the ones that improve an already great tool and make something better. Through hole components are still the fastest and perhaps most satisfying way to prototype a new electronics project so it’s extra frustrating when the happy hacker discovers their new devboard is too wide to fit in a standard breadboard. [Tobias] had the same thought and redesigned the standard ESP32 “NodeMCU” style devboard to be almost exactly the same, but narrower.

Interactive BOMs make assembly a snap

Not to trivialize, but that’s pretty much it. And we love it! The new design retains the great support of the original devboard but adds a few nice tweaks. Obviously there’s the small size change that allows it to fit on a standard 5×5 breadboard leaving sockets available on either side for interfacing. Even in this smaller size [Tobias] managed to retain the boot mode and reset buttons though the overall pinout has changed slightly. And for easier connections ye olde micro USB socket has been swapped for sleek modern USB-C. You have cables for that common standard now, right?

How do you get one? As far as we know [Tobias] isn’t selling these but the design is completely open source and the design, fab, and BOM files are all in the github repository. [Tobias] even went so far as to include the extremely handy interactive BOM to speed up hand assembly. The real trick here is that the board is designed to facilitate the extremely inexpensive turnkey assembly now available from our favorite fab houses, with an example cost of $8/piece for a run of five. The repo includes a properly formatted BOM and fab files to make ordering them a snap. See the bottom of the README for details about what to order.

A Low-Cost Current Probe For IoT Applications

When it comes to the Internet of Things, many devices run off batteries, solar power, or other limited sources of electricity. This means that low power consumption is key to success. However, often these circuits draw relatively small currents that are difficult to measure, with plenty of transient current draw from their RF circuits. To effectively measure these low current draws, [Refik Hadzialic] built a cheap but accurate current probe.

The probe consists of a low value resistor of just 0.1 Ω, acting as a current shunt in series with the desired load. By measuring the voltage drop across this known resistor, it’s possible to calculate the current draw of the circuit.

However, the voltage drop is incredibly small for low current draws, so some amplification is needed. [Refik] does a great job of explaining his selection process, going deep into the maths involved to get the gain and part choice just right. The INA128P instrumentation amplifier from Texas Instruments was chosen, thanks to its good Common Mode Rejection Ratio (CMRR) and gain bandwidth.

The final circuit performs well, competing admirably with the popular uCurrent Gold measurement tool. While less feature-packed, [Refik]’s circuit appears to perform better in the noise stakes, likely due to the great CMRR rating of the TI part. It’s a great example of how the DIY approach can net solid results over and above simply buying something off the shelf.

Current sensing is a key skill to have in your toolbox, and can even help solve laundry disputes. Video after the break.

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384 Neon Bulbs Become Attractive Display

Neon lights have inspired much prose over the years, with their attractive light output receiving glowing adulation. [Pierre Muth] is a big fan, and decided to spend lockdown creating something suitably pretty for his desk.

An 8×8 segment of the total panel. The display draws 40W at 5V with all pixels on at the same time.

The project consists of an 8×48 matrix display constructed out of INS-1 (ИНC-1) tubes. These tiny neon tubes are 6.5 mm in diameter, showing a bright orange dot of light when powered up. Requiring just 100 V and 0.5 mA to light, they’re a touch easier to drive than the famous Nixie.

[Pierre] decided to go all out, wishing to replicate the capabilities of smart LEDs like the WS2812. These contain a microcontroller built in to each LED, so [Pierre] would have to do the same. Each of the 384 neon tubes got its own bespoke PCB, containing a PIC16F15313 microcontroller, step up voltage circuitry, and a 6-pin connector. (Whoah!) When each bulb was soldered to its PCB, they were then plugged into a backplane. An ESP32 was then employed to drive the display as a whole.

Creating a display in this fashion takes a huge amount of work, with most of it being soldering the 384 individual bulb PCBs containing 11 components each. We have a lot of respect for [Pierre]’s work ethic to get this done during lockdown, and the final result is a gloriously retro neon matrix display. We’ve featured other neon matrixes recently, too. Video after the break. Continue reading “384 Neon Bulbs Become Attractive Display”

Tiny Ethernet Switch Gets Even Smaller

As a project gets more complicated, some kind of internal communication network is often used to that all of the various modules and sensors can talk with each other. For hardware hackers like us, that usually means SPI, I2C, or maybe even good old fashioned UART. But if you’re pushing a lot of data around, like live video feeds from multiple cameras, you’ll need something a bit faster than that.

Which is why [Josh Elijah] has created the SwitchBlox Nano, a three port 10/100 Ethernet switch that fits on a one inch square PCB. All you need to do is provide it with power, with a generous input range of 5 to 50 volts, connect your devices to the Molex Picoblade connectors on the board, and away you go. There’s even a 5 V 1 A regulated output you can use to run your downstream devices.

If you’ve got a feeling that you’ve seen something very similar on these pages earlier in the year, you’re not imagining things. Back in April we covered the original five port SwitchBlox in a post that garnered quite a bit of attention. In fact, [Josh] tells us that the design of this new switch was driven largely by the feedback he got from Hackaday readers. The Nano is not only smaller and cheaper than the original, but now maintains full electrical isolation between each port.

The average Hackaday reader is as knowledgeable as they are opinionated, and we’re glad [Josh] was able to put the feedback he received to practical use. We’re proud that our community has had a hand in refining successful commercial products like the Arduboy handheld game system and the Mooltipass hardware password keeper. Now it looks like we can add a tiny Ethernet switch to the list of gadgets we’ve helped push up the hill. Maybe we should get a stamp or something…