An In-Depth Comparison Of Hobby PCB Manufacturers

October 13, 2023 by 45 Comments

[Icamtuf] has been working on a prototyping run of a project, which involves getting PCBs made by several low volume PCB manufacturing companies. After receiving the boards, he analyzed the results and produced an interesting analysis.

The project he is working on is Sir-Box-A-Lot, a Sokoban gaming console clone that we’ve covered before. It uses an AVR128DA28 microcontroller to emulate the original box-pushing game and drive the OLED display. He ordered PCBs from OSHPark, DigiKey Red, JLCPCB, PCBWay and Aisler.

OSHPark boards are gorgeous, but you pay for it.

There were pros and cons for each of the services: OSHPark produced the nicest-looking boards, but at the highest cost. DigiKey Red had a flawless solder mask, but a rather sloppy-looking silkscreen and shipped the boards covered in adhesive gunk. JLCPCB was fast, shipping the boards in less than 7 days, but the smaller details of the silkscreen were blurry and the solder mask was thinner than the others. The solder mask from PCBWay was very slightly misaligned but was thicker than most, and they were the only ones who queried a badly shaped hole to see what [Icamtuf] wanted to do: the others just made assumptions and made the boards without checking.

To be fair, this analysis is based on a single PCB design ordered once and it is possible that some companies were having a bad day. These were also delivered to the US, so your delivery times may vary. So, there are no clear winners and I wouldn’t make a choice based on this alone. But the analysis is well worth a read if you want to know what to look out for on your own PCBs.

Bare PCB Makes A Decent Homemade Smart Watch

September 3, 2023 by 15 Comments

These days, we live in a post-Dick Tracy world, where you can make a phone call with your fancy wristwatch, and lots more besides. [akashv44] has gone a simpler route, designing their own from scratch with a bare PCB design.

The build is based around the ESP-12E microcontroller, providing useful wireless connectivity that lets the watch interface with the outside world. The firmware makes queries of NTP servers and Yahoo’s weather API to collect time and weather data for display. It’s also capable of interacting with Blynk relay modules for controlling other equipment, which [akashv44] uses with lights and an air conditioner. The watch uses a small OLED display and a handful of small surface-mount tactile buttons for control. Power is courtesy of a small lithium-ion pouch cell, with charging handled by a TP4056 battery management IC.

It’s a simple smartwatch, but nonetheless one that teaches all kinds of useful skills in embedded development and design. It’s also funny to think how simple it is to build. A decade ago, before the ESP8266 was released, getting wireless connectivity in such a small package was a major engineering challenge. Even the Apple Watch didn’t come out until 2015! Food for thought.

Electronic Earrings Are PCB Art You Can Wear

June 24, 2023 by 4 Comments

If there’s one area of the human anatomy we rarely try to draw the eye, it’s the ears. Nonetheless, [DIY GUY Chris] has developed some LED earrings that should do exactly that.

The earrings are made using PCBs as the very body of the jewelry itself. The PCBs for each ear play host to eight WS2812 LEDs in a tiny 2020 form factor. The LEDs get their instructions from an ATtiny13-A AVR microcontroller, with some further supporting hardware to get everything playing happily together. Each earring runs off a single CR1220 coin cell, which sits on the obverse side of the earring to stay out of sight. The earrings are programmed with pogo pins to avoid the need for any bulky connectors.

By virtue of the tiny addressable LEDs, the earrings are capable of displaying full RGB colors. [DIY GUY Chris] has programmed the earrings with simple color fades, as well  as some fancier chase animations as well.

We’ve seen some great PCB jewelry before, too. Video after the break.

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Hack Club OnBoard

Hack Club Grants Encourage Open Source PCB Designs By Teens

June 15, 2023 by 6 Comments

[Hack Club] is a nonprofit network of coder and maker clubs for teenage high school students around the world. With an impressive reach boasting clubs in about 400 schools, they serve approximately 10,000 students. Their OnBoard program asserts, “Circuit boards are magical. You design one, we’ll print it!”

Any teenage high school student can apply for a [Hack Club] OnBoard Grant to have their Printed Circuit Board design fabricated into real hardware.  The process starts by designing a PCB using any tool that can generate Gerber files. The student then publishes their design on GitHub and submits the Gerber files to a PCB manufacturer.

A screenshot from the board house showing the completed design upload and production cost is the main requirement of the grant application.  If approved, the grant provides up to $100 to cover PCB manufacturing costs.

OnBoard encourages collaboration, community, and friends. Designers can share their projects and progress with [Hack Club] teens around the world. Those who are working on, or have completed, their own circuit board designs can share support and encouragement with their peers.

Example hardware projects from [Hack Club] include Sprig, an open-source handheld game console based on the Raspberry Pi Pico microcontroller.  Teen makers can explore the example OnBoard projects and then it’s… three, two, one, go!

PC Classics, Right In Your Browser With EmuOS

May 6, 2023 by 11 Comments

[Emupedia]’s work to preserve computer history by way of making classic and abandoned games and software as accessible as possible is being done in a handy way: right in your browser with EmuOS.

A few moments of BIOS startup kicks off EmuOS right in a browser window.

Doing things this way has powerful “Just Works” energy. Visit that link in a modern browser and in no time at all you’ll be looking at a Windows 95 (or Windows 98, or Windows ME) desktop, filled with a ton of shortcuts to pre-installed and ready-to-run classic software. Heck, you can even keep it simple and be playing the original Microsoft Solitaire in no time flat. There is also a whole ton of DOS software waiting to be fired up, just double-click the DOSBox icon, and browse a huge list. The project is still in development, so not everything works, but the stuff that does is awfully slick.

Here’s some additional background that goes into more detail about the project and its capabilities, but if you’d prefer to just click around to explore, here’s the main link again (and here’s a list of mirrors.)

If OS emulation is your thing, don’t miss emulating the IBM PC on an ESP32 microcontroller. And if you’re more into lesser-known vintage operating systems, how about re-inventing PalmOS to run on x86 architecture?

Run Linux By Emulating RISC-V On A RISC-V Microcontroller

April 23, 2023 by 7 Comments

For years it was a given that it was impossible to run a Linux based operating system on a less powerful computer whose architecture lacked a memory management unit. There were projects such as uCLinux which sought to provide some tidbits to low computing power Linux users, but ultimately they came to naught. It is achievable after a fashion though, by using the limited architecture to emulate a more powerful one. It’s been done on AVR chips emulating ARM, on ARM chips, and now someone’s done it on an ESP32-C3 microcontroller, a RISC-V part running a RISC-V emulator. What’s going on?

RISC-V is an architecture specification that can be implemented at many levels from a simple microcontroller or even a pile of 74 logic to a full-fat application processor. The ESP32-C3 lies towards the less complicated end of this curve, though that’s not the whole reason for the emulation. The PSRAM storage is used by the C3 as data storage and can’t be used to run software, so to access all that memory capacity an emulator is required that in turn can use the PSRAM as its program memory. It’s a necessary trick for Espressif’s implementation of the architecture.

Surprisingly it’s not as slow as might be expected, with a boot-up time under two minutes. It’s not what we’d expect from our desktop powerhouses, but it’s not so long ago that certain lower-power full-fat processors could be just as lethargic. For past glories, see the AVR running Linux, and the RP2040.

PCB Gets Weighty Assignment

January 5, 2023 by 9 Comments

[Curious Scientist] tried building an integrated strain gauge on a PCB, but ran into problems. Mainly, the low resistance of the traces didn’t show enough change under strain to measure easily. Even placing a proper strain gauge on the PCB had limitations. His new design uses a bridge design to make the change in the gauges usefully large. You can see a video of the project below.

Bridging strain gauges isn’t a new idea. However, the novelty of this design is that the PCB has cantilever beams that facilitate the weighing. Standoffs mount a plate to the beams so that weight on the plate cause deformation on the beam that the strain gauges can measure.

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