SMD Soldering, Without The Blobs

March 30, 2024 by Jenny List 23 Comments

Hand soldering of surface mount components is a bread-and-butter task for anyone working with electronics in 2024. So many devices are simply no longer available in the older through-hole formats, and it’s now normal for even the most homebrew of circuits to use a PCB. But how do you solder your parts? If like us you put a blob of solder on a pad and drop the part into it, then [Mr. SolderFix] has some advice on a way to up your game.

The blob of solder method leaves a little more solder on the part than is optimal, sometimes a bulbous lump of the stuff. Instead, he puts a bit of flux on the pad and then applies a much smaller quantity of solder on the tip of his iron, resulting in a far better joint. As you can see in the video below, the difference is significant. He starts with passives, but then shows us the technique on a crystal, noting that it’s possible to get the solder on the top of these parts if too much is used. Yes, we’ve been there. Watch the whole video, and improve your surface mount soldering technique!

He’s someone we’ve featured before here at Hackaday, most recently in lifting surface mount IC pins.

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Night Vision The Old Way

March 26, 2024 by Al Williams 7 Comments

Solid state electronics have provided lighter weight night vision units that work better than the old-fashioned gear that used photomultiplier tubes, but there was an even older technology as [Our Own Devices] shows us in a recent video. The Metascope Type B was a first-generation passive night vision viewer that relied on moonlight.

The video shows a 1946 technical paper from the Office of Scientific Research and Development with [Vannevar Bush] credited as the institute’s director. If that name sounds familiar, you may remember that he foresaw hypertext (inspiring both [Doug Englebart] and the creation of the Web).

The Type B was an improvement over the older Type A, which had been tested during the invasion of North Africa in 1942. The type A weighed less than two pounds and was much smaller than the type B. However, it didn’t work very well, so they stopped making them and did a redesign, which is what you see in the video. The type B weighed almost 5 pounds.

To use the metascope, you had to “charge” it with light and then wait. Eventually, you’d need to charge it again. The type B allowed you to charge one phosphor plate while using another one. When that plate became weak, you could swap the plates to continue using the device.

If you aren’t keen on the history, you can skip to just before the 15-minute mark of the video for the hardware examination. He doesn’t open the device, but that’s probably wise, given the nature, age, and rarity of the metascope.

Modern image sensors are very sensitive to infrared, and normal cameras usually have filters to keep them out. Not that you can’t remove it, of course. If you want to see something more modern, [Nick] built his own AN/PVS-14 night vision scope and you can too.

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Are Minimills Worth It?

March 25, 2024 by Al Williams 64 Comments

These days, the bar for home-built projects is high. With 3D printers, CNC, and cheap service providers, you can’t get away with building circuits in a shoe box or an old Tupperware container. While most people now have access to additive manufacturing gear, traditional subtractive equipment is still a bit less common. [Someone Should Make That] had thought about buying a “minimill” but he had read that they were not worth it. Like a lot of us, he decided to do it anyway. The pros and cons are in the video you can watch below.

During setup, he covered a few rumors he’d heard about these type of mills, including they are noisy, have poor tolerances, and can’t work steel. Some of these turned out to be true, and some were not.

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AxxSolder 3.0 Now Takes USB Power Delivery

March 25, 2024 by Lewin Day 12 Comments

If you’re big into the soldering iron scene, you’ve probably heard of the AxxSolder project. Now, it’s been updated with a whole host of nifty new features. It’s AxxSolder 3.0!

If you’re not intimately familiar with AxxSolder, it’s an open-source iron design based around the popular JBC soldering iron tips. Relying on the STM32G431CBT6 to run the show, it comes in two versions—a lightweight portable design, and a desktop version based around the JBC ADS soldering iron stand. So far, so familiar.

The new 3.0 version adds new functionality, however. Where the previous model ran off any old DC power source from 9 to 26 volts, the new version can run off a USB Power Delivery supply. Thus, you can grab any old USB-PD device, like a laptop charger, and run your iron off that.

The new version also uses a larger color TFT screen with some buttons added on as an improved user interface. Thermal performance is improved, and it’s additionally capable of measuring the current draw by the tip, so you can monitor the performance of the iron in great detail.

We’ve featured the AxxSolder project previously, too, along with some other great soldering iron projects. If you reckon you’ve just designed the hottest new soldering tool yourself, let us know about it!

A raspberry pi-based digital readout above an old lathe

Roll Your Own DRO With An Added Twist

March 22, 2024 by Dave Rowntree 4 Comments

When using a manual machine tool such as a lathe or milling machine, there can be a lot of pressure to read the position and feed the axes at the correct rate. That’s why modern machines typically have some form of digital read-out (DRO). [Stefano Bertelli] has created a simple Raspberry Pi based DRO with an additional twist, that of a linked motor drive output.

A view of the custom RS485 interfaced DRO readout and motor controller — Realtime encoder position reading and motor control are best done with a dedicated microcontroller, ideally with a proper RTOS.

The axes that need to be monitored should be mechanically attached to a position sensor like a linear encoder or a rotary type. Using a linear sensor with a linear axis instead of a rotary encoder on the downstream dial is better. For the readout unit, [Stefano] used a WaveShare 7-inch touchscreen module with a Raspberry Pi 3 for the UI of the readout unit. The Pi has a custom-designed HAT, that performs power conditioning and provides a robust RS485 interface. Connected via that RS485 link is another custom PCB based on an STM32F411 with a few supporting power supplies and interfacing components. The job of this board is to interface to the position encoders, reading positioning pulses using interrupts. There is an additional stepper motor drive courtesy of a ULN2003 Darlington driver to allow the control of a single motorised axis. An additional motor driver module is required, which should be no surprise since driving a milling machine axis will require a fairly beefy motor. This GitHub repo contains the FreeRTOS-based firmware for this board. This motor drive has the ability to be connected to a measuring axis in a programmable way, enabling one axis to be adjusted to follow or jump in controlled steps with another. This feature can significantly simplify certain types of machining operations, as [Stefano] elaborates in the video.

Lastly, the Raspberry Pi runs a simple Python application with Kivy for the GUI. As [Stefano] explains in the video below, this makes debugging and modification quite simple.

Adding DROs to an older machine is an obvious but valuable hack. Here’s another way to do it. If that’s too much work, then you could just hack a digital readout calliper in there.

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Modern Microcontroller Boosts Classic Logic Analyzer To New Heights

March 19, 2024 by Lewin Day 5 Comments

[Ted Fried] recently found a beautiful HP 1600A/1607A logic analyzer set. State of the art in 1975, it looks like glorious Space Age equipment today. He decided to hook it up some modern gear to put it through its paces.

Wanting to give the equipment a proper shakedown, he enlisted a Teensy 4.1 to spit a deluge of logic at the HP unit. The microcontroller was tasked with generating 32 data signals along with two clock outputs to give the analyzer plenty to analyze. The HP 1600A handled this no problem, so [Ted] kept tinkering.

His next feat was to explore the addressable “MAP” function of the unit, which allowed writing to the 64×64 pixel display. The Teensy 4.1 was easily able to send images to the display, but [Ted] isn’t stopping there. He’s got plans to do the usual thing and get Bad Apple going on the hardware.

Getting a logic analyzer to analyze logic isn’t much of a hack, sure. But it’s instructive of how to approach working with such hardware. If you want to spit a bunch of logic out fast, a Teensy 4.1 is a great choice because it’s got a ton of IO and a ton of clock cycles to tickle it with.

We enjoyed seeing this old piece of hardware light up the phosphors once more. If you’ve got your own projects going on with classic bits of HP test gear, don’t hesitate to let us know!

Faux Silkscreen On A PCB Made With A Laser Cutter

March 18, 2024 by Lewin Day 13 Comments

If you’re getting PCBs professionally made, silkscreen usually comes free as part of the package. However, if you’re making your own, the job is on you. [Tony Goacher] makes his own PCBs on a CNC router, so he’s not getting any silkscreening as part of that bargain. But he wondered—could he do something analogous with a laser cutter?

The answer is yes. The silkscreen layer was first exported from DesignSpark, with the file then sent to LightBurn to prep it for laser cutting. The board outline layer was first engraved on to a piece of scrap as an alignment aid. Then, the board was placed in the laser cutter, with the silkscreen scorched directly on to the fiberglass.

The results are encouraging, if imperfect. [Tony] says he ran at “quite fast speed at quite high power.” The markings are all there, but they’re a little melty and difficult to read. He noted at lower speeds and lower power, the results were a bit more readable.

PCBs aren’t really an ideal engraving or laser marking material, but this technique could be servicable for some basic markings on DIY PCBs. We look forward to seeing how [Tony] improves the process in future. Video after the break.
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