pcb

637 Articles

CNC Router And Fiber Laser Bring The Best Of Both Worlds To PCB Prototyping

March 4, 2025 by 22 Comments

Jack of all trades, master of none, as the saying goes, and that’s especially true for PCB prototyping tools. Sure, it’s possible to use a CNC router to mill out a PCB, and ditto for a fiber laser. But neither tool is perfect; the router creates a lot of dust and the fiberglass eats a lot of tools, while a laser is great for burning away copper but takes a long time to burn through all the substrate. So, why not put both tools to work?

Of course, this assumes you’re lucky enough to have both tools available, as [Mikey Sklar] does. He doesn’t call out which specific CNC router he has, but any desktop machine should probably do since all it’s doing is drilling any needed through-holes and hogging out the outline of the board, leaving bridges to keep the blanks connected, of course.

Once the milling operations are done, [Mikey] switches to his xTool F1 20W fiber laser. The blanks are placed on the laser’s bed, the CNC-drilled through holes are used as fiducials to align everything, and the laser gets busy. For the smallish boards [Mikey] used to demonstrate his method, it only took 90 seconds to cut the traces. He also used the laser to cut a solder paste stencil from thin brass shim stock in only a few minutes. The brief video below shows the whole process and the excellent results.

In a world where professionally made PCBs are just a few mouse clicks (and a week’s shipping) away, rolling your own boards seems to make little sense. But for the truly impatient, adding the machines to quickly and easily make your own PCBs just might be worth the cost. One thing’s for sure, though — the more we see what the current generation of desktop fiber lasers can accomplish, the more we feel like skipping a couple of mortgage payments to afford one.

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A History Of Copper Pours

January 31, 2025 by 39 Comments

If you compare a modern PCB with a typical 1980s PCB, you might notice — like [lcamtuf] did — that newer boards tend to have large areas of copper known as pours instead of empty space between traces. If you’ve ever wondered why this is, [lcamtuf] explains.

The answer isn’t as simple as you might think. In some cases, it is just because the designer is either copying the style of a different board or the design software makes it easy to do. However, the reason it caught on in the first place is a combination of high-speed circuitry and FCC RF emissions standards. But why do pours help with unintentional emissions and high-speed signals?

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DIY Probe Clamps To Ease Your PCB Work

January 27, 2025 by 9 Comments

Those of us familiar with PCB work would agree that anything that helps hold probes secure and hands-free to components, traces, or test points is worth looking at. That’s where [2048bits]’ snap probe design comes in. With a little additional and inexpensive hardware, one can have all the hands-free probe clamps one’s workbench can fit!

That first link is where you’ll find a list of required hardware and the CAD files (in .step format) for the probe itself. The obvious approach to making the pieces would be to 3D print them, but we notice the design — while attractive — looks like a challenging print due to the features. We’re not the only ones to see that, and happily there’s already a remix by [user_2299476772] aimed at keeping the essential features while making them easier to print.

If you’re taking a DIY approach to PCB probes, we’d like to remind you that one of our readers discovered dental burrs make absolutely fantastic, non-slip probe tips. This seems like a good opportunity to combine two ideas, and having the CAD files for the probe clamp means modification is straightforward. Let us know on the tips line if you get something working!

[via Hackster]

Smallest USB Device… So Far

January 20, 2025 by 37 Comments

For better or worse it seems to be human nature to compete with one another, as individuals or teams, rather than experience contentedness while moving to the woods and admiring nature Thoreau-style. On the plus side, competition often results in benefits for all of us, driving down costs for everything from agriculture to medical care to technology. Although perhaps a niche area of competition, the realm of “smallest USB device” seems to have a new champion: this PCB built by [Emma] that’s barely larger than the USB connector pads themselves.

With one side hosting the pads to make contact with a standard USB type-A connector, the other side’s real estate is taken up by a tiny STM32 microcontroller, four phototransistors that can arm or disarm the microcontroller, and a tiny voltage regulator that drops the 5V provided by the USB port to the 3.3V the STM32 needs to operate. This is an impressive amount of computing power for less than three millimeters of vertical space, and can operate as a HID device with a wide variety of possible use cases.

Perhaps the most obvious thing to do with a device like this would be to build a more stealthy version of this handy tool to manage micromanagers, but there are certainly other tasks that a tiny HID can be put to use towards. And, as far as the smallest USB device competition goes, we’d also note that USB-A is not the smallest connector available and, therefore, the competition still has some potential if someone can figure out how to do something similar with an even smaller USB connector.

Thanks to [JohnU] for the tip!

Simple Hardware Store Hack Keeps Your PCBs Right Where You Want Them

January 16, 2025 by 30 Comments

Sometimes it’s the simplest hacks that make the biggest impact.

Take these DIY magnetic PCB vises for example. Sure, you can go out and buy purpose-built tools, but [Dylan Radcliffe] just made a trip to the hardware store for some nuts and bolts. He chose 3/8″-16 bolts, which would probably be around M10 for the rest of the world. The head of each bolt is ground flat so a ceramic disc magnet can be attached to it with CA glue, while the head of the bolt gets a plastic washer glued to it. Another plastic washer gets glued to a nut, which when threaded onto the bolt provides the light clamping force needed to hold a PCB. Make four of those and stick them to a steel plate with the magnets, and you can stop chasing your boards around the bench with a soldering iron.

As much as we like this idea — and we do; we’re heading to Home Depot to buy the needed parts this very evening — we can think of a few useful modifications. With a long bolt and two nuts rather than one, you could make a set of vises that are easily adjustable along the Z-axis. This could prove useful to those of us working under a microscope. Also, rather than making the bolts the magnetic part we bet you could lay down a flexible magnetic sheet, the kind you can feed into a printer to roll your own fridge magnets. We suspect that would hold the bolts firmly enough for most work while still allowing easy repositioning. We’d also favor flange nuts over plain hex nuts, to give a larger clamping area. We’d still include the plastic washers, though, or possibly switch to rubber ones.

There’s more than one way to skin this cat, of course, especially if you’ve got a Harbor Freight nearby and a well-stocked Lego bin.

Game boy with custom cartridge mounted on car dashboard

A Game Boy Speedometer, Just Because You Can

January 15, 2025 by 8 Comments

From a practical standpoint, [John] may be correct that his recent creation is the “world’s worst digital dash”, but we’re still oddly enamored with the idea of using a Nintendo Game Boy as a digital speedometer. Pulling it off meant interfacing the handheld with the vehicle’s CAN bus system, so whether you’re into retro gaming or car hacking, this project has something to offer.

Showing real-time vehicle speed on the Game Boy sounds like it should be relatively easy, but the iconic game system wasn’t exactly built for such a task. Its 2 MHz CPU and 160×144 pixel dot-matrix screen were every kid’s dream in 1989, but using it as a car dashboard is pushing it. To bridge that gap, [John] designed two custom circuit boards. One interfaces with the Game Boy, intercepting its memory requests and feeding it data from a microcontroller. The other processes the CAN bus signals, translating speed information into a form the Game Boy can display. [John] used inexpensive tools and software to read the CAN bus data, and used GBDK-2020 to write the software in C. His video goes in great detail on how to do this.

Months of work have gone into decoding the Game Boy’s data bus and creating a schematic for the interface board. Tricking the Game Boy into thinking it was loading a game, while actually displaying incoming speed data. The screen’s low resolution and slow refresh rate rendered it barely readable in a moving vehicle. But [John]’s goal wasn’t practicality — it was just proving it could be done.

Want to dive deep into the Game Boy?  Have you seen the Ultimate Game Boy talk?

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Bit-Banging The USB-PD Protocol

January 10, 2025 by 14 Comments

For one-off projects, adding a few integrated circuits to a PCB is not too big of a deal. The price of transistors is extremely low thanks to Moore and his laws, so we’re fairly free to throw chips around like peanuts. But for extremely space-constrained projects, huge production runs, or for engineering challenges, every bit of PCB real estate counts. [g3gg0] falls into the latter group, and this project aims to remove the dedicated USB-PD module from a lighting project and instead bit-bang the protocol with the ESP32 already on the board.

The modern USB power delivery (PD) protocol isn’t quite as simple as older USB ports that simply present a 5V source to whatever plugs itself into the port. But with the added complexity we get a lot more capability including different voltages and greater power handling capabilities. The first step with the PD protocol is to communicate with a power source, which requires a 1.2V 600kHz signal. Just generating the signal is challenging enough, but the data encoding for USB requires level changes to encode bits rather than voltage levels directly. With that handled, the program can then move on to encoding packets and sending them out over the bus.

After everything is said and done, [g3gg0] has a piece of software that lets the ESP32 request voltages from a power supply, sniff and log PD communication, and inject commands with vendor defined messages (VDM), all without needing to use something like a CH224K chip which would normally offload the USB-PD tasks. For anyone looking to save PCB space for whatever reason, this could be a valuable starting point. To see some more capabilities of the protocol, check out this USB-PD power supply that can deliver 2 kW.