QRP-Labs Filter Adapter for NanoVNA

Cabe Atwell writes on Hackster about a RF filter adapter was made using some spare parts and lowpass and bandpass filter kits:


QRP-Labs Filter Adapter for NanoVNA

Check out Lex Bolkesteijn’s new project constructing a QRP-Labs filter adapter for NanoVNA with some spare parts and lowpass and bandpass filter kits. The NanoVNA is a tiny handheld Vector Network Analyzer (VNA), which accomplishes both high-performance and portability. Besides working as a vector network analyzer and antenna analyzer, this build utilizes it as a filter tuner.

A current work in progress, last updated in mid-June, it was developed using a double-sided PCB, two SMA chassis, and a header cut in two to form a filter holder that enabled the use of the NanoVNA to test and tune the filters as required. The filter kits themselves include the double-sided PCD along with silkscreen, solder mask, and through-hole plating, as well as the capacitors. Both are the same size, and so require no adjustments to the filter holder.

Although the filter has four pins, five holes are drilled in the PCB base of the filter holder using a perforated PCB for spacing. The fifth hole allows for a via to connect the top and bottom layers. With some soldering, the via, SMA chassis parts, and headers are connected to the base. In a few steps that, everything is set up to connect the filter to the NanoVNA.

The NanoVNA should be calibrated before use, and in the documented project, this was done with an experimental calibration tool. When calibrating as close as possible to the adaptor, it’s not possible to use the calibration standards. The calibration tool was made with another PCD, with holes drilled for vias and two 100 Ohm SMD 1206 resistors.

A design, complete with CAD files for the casing, is also included for those who are unable to mill PCBs by hand. This uses a 3D-printed casing and custom-ordered PCBs to serve as the adapter. Simplifying the manual work required in the design, even more, the most recent custom PCB ordered includes built-in calibration options. The 3D-printed base looks spiffier than the hand-milled PCBs and requires no additional PCB for calibration.

For anyone interested, the bill of materials, CAD files, and a step-by-step with images are freely available on Bolkesteijn’s blog.

QRP-Labs Filter Adapter for NanoVNA

Introducing EDeA: An Open Platform for Easily Reusable Subcircuits

This looks like a promising way to make PCB design more efficient by leveraging the existing open source hardware designs:

Screenshot from 2020-07-30 11-02-22

Introducing EDeA

We’re building an open-source web portal for sharing KiCad subcircuits, which will enable you to create more by doing less.

This is what inspired the EDeA project. Out of a very naïve “how hard can this be?” question, we first built a primitive prototype tool to merge KiCad projects, including their schematics and PCB layout. This still need a lot of work before it can be considered safe, including correct net aliasing, nesting of subschematics, etc. But this solves only one part of the problem, something which should be solved in the upcoming major release of KiCad anyways.

We are now laying the groundwork for EDeA; a community portal to share, find, and assemble subcircuits into KiCad projects. It’s all in rough shape, and we’re still a bit away from the first alpha we will show to the public, but we’re getting there.

What we envisioned is an easy-to-use catalog of various circuit submodules; power supplies, data converters, microcontrollers, processors, and so on. These submodules contain schematics and a PCB layout, among with useful metadata; number of copper layers, component count, surface area, necessary manufacturing capabilities, and so on. Each of the subcircuit category should also have meaningful parameters; for example efficiency for a power supply, bandwidth for a transceiver. You can select any amount of these submodules, click a button, and get a KiCad project which contains all the submodules as hierarchical subsheets. Now you only need to wire these together as you need them, and in pcbnew move the already layouted submodules to fit the exact shape you need. To keep the already complex project manageable, we can’t go into auto-connecting and auto-placing of submodules. At least not yet.

Introducing EDeA: An Open Platform for Easily Reusable Subcircuits

Obsidian Boa: Greg Davill squeezes the ESP32 into a ItsyBitsy

Tom Fleet writes on Hackster about the latest open source board from the prolific Greg Davill:


Meet Obsidian Boa: This ItsyBitsy — with WiFi — Is What It’s All About!

No, we’re not branching out into nursery rhymes, but it’s too hard to pass up on the chance offered by the latest development from Hackster favorite Greg Davill!

With the dust in his workshop only just settling (if that’s possible there…) from his successful OrangeCrab crowdfunding campaign, he’s gotten straight back to work, turning his sights from the Lattice ECP5, and setting them squarely on the Espressif Systems ESP32, with his latest creation — the ObsidianBoa!

While the above image is a render, the quality of Davill’s work shines through in both the the physical and the virtual world — some of his recent rendering work is hard to tell from reality.


While there are a number of ESP32 development boards, there are few in such a diminutive form factor. The only one I know of, until now, has been the TinyPICO, from @unexpectedmaker. This is a fantastic board in it’s own right, and has been rightfully successful within the maker community.

Obsidian Boa has a few notable differences however, which might make it more suitable for certain applications.

The first point of note is where we get the title of this article from. Not just a descriptive phrasing, ItsyBitsy is a lesser-heard-of form factor — and just as we all know boards in the Arduino R3 layout, or the hugely popular Feather form factor from Adafruit, ItsyBitsy started out life as yet another Adafruit board format, and was shortly thereafter realized as a baby brother alternative to the well known iCEBreaker FPGA boards.


Obsidian Boa: Greg Davill squeezes the ESP32 into a ItsyBitsy

CR2032 Battery PCB adapter for Yamaha DX7 synth


Here is a quick “freebie” of sorts. I’ve had this PCB for a while and used them now and then to fix dead 3v coin cell batteries on Yamaha DX7’s and other synth’s and drum machines. You can order the blank PCBs yourself or download the BRD file and get them made however you want.

OSH Park Shared project MTG CR2032 PCB Saver, Rev A

This item is a battery holder/coin cell adapter PCB that lets you mount a standard CR2032 battery holder over top of a PCB layout that uses a soldered-in battery. It basically converts the pin layout from one of many odd 2- pin and 3-pin board styles into the common battery holder style. In the future, battery replacement will be a snap! Save your gear from leakage, damaged traces and lost sounds! Was designed for Yamaha DX7 synth. The Instructions are here.


CR2032 Battery PCB adapter for Yamaha DX7 synth

The Simplest TS100 Upgrade Leads Down A Cable Testing Rabbit Hole

By now, I must have had my Miniware TS100 soldering iron for nearly three years. It redefined what could be expected from the decent end of the budget soldering iron spectrum when it came on the market, and it’s still the one to beat even after those years. Small, lightweight, powerful, and hackable, it has even spawned direct imitations.

If the TS100 has a fault, it comes not from the iron itself but from its cable. A high-grade iron will have an extra-flexible PVC or silicone cable, but the TS100 does not have a cable of its own. Instead it relies on whatever cable comes on its power supply, which is frequently a laptop unit built with portable computing rather than soldering in mind. So to use it is to be constantly battling against its noticable lack of flexibility, a minor worry but one that I find irksome. I determined to find a solution, making a DC extension cable more flexible than that on my power supply.

via The Simplest TS100 Upgrade Leads Down A Cable Testing Rabbit Hole — Hackaday


AXIOM: open source cinema camera at FOSDEM

Sebastian Pichelhofer of Apertus gave an exciting talk at FOSDEM earlier this year and the video is now on YouTube:

AXIOM – open source cinema camera Project Introduction and current state of development

The presentation will give a brief overview of the projects history & lessons learned during the course of developing a high tech camera device as community project. We also want to demo and explain the produced hardware, enclosures and sample footage then look at the challenges still ahead. Last 5 minutes reserved for Q&A

Screenshot from 2020-07-26 16-04-03

AXIOM: open source cinema camera at FOSDEM

The nRF9160 Feather Is Now Served

Jared Wolff has design a Feather form factor board with the nRF9160:


The nRF9160 Feather Is Now Served

Low-power shutdown, built-in 4FF SIM card slot, flexible power supply, and more.

I was a complete failure. My prototype wasn’t working. I spent at least an hour trying to rework a frustratingly large LTE module on an impossibly small circuit board.

It wasn’t going to work.

So I went back to the drawing board. I poured my years of hardware experience into a tiny form factor.

The end product?

Something smart. Something with LTE, NB-IoT, and GPS. Something anyone could get started with right away.

And thus, the nRF9160 Feather was born.

I need your help! 🙏

To make this campaign a reality, I need your help to meet our minimum order quantity of nRF9160 Feathers. Without that, we’re dead in the water! Head on over to the campaign page to reserve yours.

For those of you who’ve already committed, I thank you from the bottom of my heart. I can’t wait to get the nRF9160 Feather into your hands!

P.S. Huge thanks to Hackster and GroupGets for making this happen. You guys and girls are great. ❤


The nRF9160 Feather Is Now Served

Ordering from OSH Stencils is now easier

Back in 2019, we added ability to order a stencil for your board design from OSH Stencils:

We have extended that capability so you can order from OSH Stencils based on the paste layers from your past OSH Park orders:

Ordering from OSH Stencils is now easier

Printed TS100 Case Beats the Heat with a Bearing

As we’ve said many times in the past, the creation of custom cases and enclosures is one of the best and most obvious applications for desktop 3D printing. When armed with even an entry-level printer, your projects will never again have to suffer through the indignity of getting hot glued into a nondescript plastic box. But if you’re printing with basic PLA, you need to be careful that nothing gets too hot inside.

Which was a problem when [Oleg Vint] started work on this 3D printed case for the popular TS100 soldering iron. But with the addition of a standard 608 bearing, the case provides a safe spot for the iron to cool off before it gets buttoned back up for storage. Of course, you can also use the flip-out perch to hold the iron while you’re working.

As [Oleg] explains on the Thingiverse page for the case, he actually blended a few existing projects together to arrive at the final design. Specifically, the idea of using the 608 bearing came from a printable TS100 stand originally designed in 2017 by [MightyNozzle]. Released under Creative Commons, [Oleg] was able to mash the bearing stand together with elements from several other printable TS100 cases to come up with his unique combined solution.

via Printed TS100 Case Beats the Heat with a Bearing — Hackaday