RFM9x module held in an adapter board with flexipins

FlexyPins Might Help With Those Pesky Castellated Modules

March 7, 2022 by Arya Voronova 51 Comments

[SolderParty] just announced FlexyPins (Twitter, alternative view) – bent springy clips that let you connect modules with castellated pins. With such clips, you can quickly connect and disconnect any castellated module, swapping them without soldering as you’re prototyping, testing things out, or pre-flashing modules before assembly. They’re reportedly gold-plated, and a pack of ~100 will set you back 6EUR, shipping not included.

Of course, this is basically “fancy pieces of wire”, purpose-shaped, gold-plated and, hopefully, made out of material that is springy enough and doesn’t snap easily after bending a few times. We’ve seen this concept used for prototyping before, with random pieces of wire doing a pretty good job of maintaining connectivity, but these clips bring it that much closer to production-grade. It also makes us wonder – just how hard it is to solder 30-40 of them into a circuit? Do they self-align enough with the footprints given, or do you have to hold them with tweezers at a peculiar angle as you solder them? Time will tell, of course.

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How To Solder To Aluminum, Easily

March 6, 2022 by Donald Papp 53 Comments

[Ted Yapo] shared a method of easily and conveniently soldering to aluminum, which depends on a little prep work to end up only slightly more complex than soldering to copper. A typical way to make a reliable electrical connection to aluminum is to use a screw and a wire, but [Ted] shows that it can also be done with the help of an abrasive and mineral oil.

Aluminum doesn’t solder well, and that’s because of the oxide layer that rapidly forms on the surface. [Ted]’s solution is to scour the aluminum with some mineral oil. The goal is to scrape away the oxide layer on the aluminum’s surface, while the mineral oil’s coating action prevents a new oxide layer from immediately re-forming.

After this prep, [Ted] uses a hot soldering iron and a blob of solder, heating it until it sticks. A fair bit of heat is usually needed, because aluminum is a great heat conductor and tends to be lot thicker than a typical copper ground plane. But once the aluminum is successfully tinned, just about anything can be soldered to it in a familiar way.

[Ted] does caution that mineral oil can ignite around 260 °C (500 °F), so a plan should be in place when using this method, just in case the small amount of oil catches fire.

This looks like a simple technique worth remembering, and it seems easier than soldering by chemically depositing copper onto aluminum.

DIY Injection Molder Built From A Cheap Pneumatic Press

March 6, 2022 by Dave Rowntree 10 Comments

[Kurt Schaefer] was watching YouTube videos of people making molds for injection molding purposes using what he considered to be the toy 3018 CNC machines, and looking at the results, decided he needed a piece of the action. However, once you have molds, the next obvious issue to address is lack of access to an injection molding machine. But these things are expensive. As luck would have it, you can get a nice-looking pneumatic press for less than $350, and with a little more money spent, [Kurt] found he could convert it into a functional injection molding machine (video, embedded below), and get some half-decent results out of it.

After ordering the press on eBay, what eventually arrived was quite a mess, having clearly been inadequately packed for its weight, and had sustained some damage in transit. Despite this, it seemed the functional bits were fine, so [Kurt] decided to press on with the build. The first obvious change is the requirement of a heated chamber to deal with the feedstock material. Using an off-the-shelf injection molding chamber by buster beagle 3D, only a few standoffs and a support bracket needed machining in order to complete the mechanics. A common PID controller available from the usual suppliers, with some heat bands wrapped around the chamber, dealt with the injection temperature requirements, and some 3D printed enclosures wrapped it all up neatly.

After some initial wobbles, and a couple of hacks to the design, [Kurt] got some pretty good results out of this simple setup, and it appears to be pretty tune-able and repeatable, which will help maintain the quality of those results. In short, a neat hack of easy to get parts, and perhaps a welcome addition to a hackerspace near you?

3D printed parts are available on the Thingiverse page, as well as a Fusion360 CAD model. The shopping list for parts can be found in the video description, if you want to have a go at reproducing this.

We’ve seen a few DIY injection molding attempts over the years, like this slick plastic molding setup. Here’s one with 3D-printed molds, and if you just need something the right shape, you could just injection mold with a hot glue.

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Low-Cost, Two-Channel Scriptable Waveform Generator

March 5, 2022 by Chris Lott 14 Comments

Microcontroller addict [Debraj] decided to make his own programmable sine wave generator, and was able to put it together for under $40 USD. Other than low-cost, his list of requirements was as follows:

Dual sine wave output, synchronized
Frequency, Amplitude, and Phase control
Low harmonics under 1 MHz
Scriptable via Python

The heart of the project is the Analog Devices AD9833, a complete Direct Digital Synthesis (DDS) waveform generator system on a chip. If you’ve ever rolled your own DDS using discrete ICs or in an FPGA, you can appreciate the benefit of squeezing the phase accumulator, sine lookup table, DAC, and control logic all into a single ten-pin package. [Debraj] uses AD9833 modules from the usual online vendors for a few dollars each. He synchronizes the generators by disconnecting the reference crystal on the second module and driving it from the first one. The remaining specifications are met by the inherent characteristics of the DDS system, and the scriptable interface is accomplished with an Arduino controlling the AD9833 chips and two programmable gain amplifiers (MCP6S31). We like the confidence that [Debraj] displays by sketching the initial circuit diagram with a ball-point pen — check out the sketch and the final pictorial schematic in the video below the break.

This is a good example of combining off-the-shelf modules to quickly build a project. This approach is great for one-off builds or as a proof-of-concept test bed that can later be spun onto a custom PCB. Another reason to use modules these days is that the modules are often in-stock but the chips are unobtainable. Though it appears [Debraj]’s only needs one of these generators, it would be an easy board to layout and build — if you can buy the parts.

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Hardware Hacking 101 Needs Matching Toolkit

March 3, 2022 by Donald Papp 21 Comments

One doesn’t always have the luxury of sipping tea comfortably while hacking a piece of hardware at a fully-equipped workbench, where every tool is within reach. To address this, [Zokol] shares an early look at a hardware hacking toolkit-in-progress, whose purpose is to make hacking sessions as productive as possible while keeping size and weight within reasonable limits. There isn’t a part list yet, but there are some good tips on creating your own.

To put together an effective hardware hacking toolkit, one must carefully consider what kinds of tasks need to be performed, and in what order. Once a basic workflow is identified, one can put together a set of complementary hardware tools and resources to meet the expected needs. The goal is to have the tools to go as far as one can in a single session, and identify any specialized equipment that will be needed later. That way, follow-up sessions can be as effective as possible.

Since hardware hacking is all about inspecting (and possibly modifying the behavior of) electronic devices, [Zokol] observes that step one is always to begin with external interfaces. That means common cables and adapters should all be part of a hardware hacking toolkit, otherwise the session might end awfully early. The next step is to open the device, so common tools and ways to deal with things like adhesives are needed. After that, diagnostic tools like multimeters come into play, with tools becoming more specialized as investigation proceeds. It’s a very sensible way to approach the problem of what to bring (and not bring) in a hardware hacking toolkit, and we can’t wait to see what the final version looks like.

Hardware hacking sometimes involves hardware that can’t be opened without damaging it. The Google Stadia controller is one such piece of hardware, and [Zokol] addressed the problem of how to permanently disable the microphone by figuring out exactly where to drill a hole.

Internal Combustion Torque Monster Has Great Impact

March 3, 2022 by Ryan Flowers 26 Comments

Once the domain of automotive repair shops and serious hobbyists with air compressors, the impact driver so famously used to remove and install wheel lug nuts and other Big Fasteners with just a squeeze of the trigger is more accessible than ever. Thanks to Lithium Ion batteries and powerful and compact brushless motors, you can now buy a reasonably powerful and torquey impact driver for a relatively low price- no air compressor needed! But what if you relish the thought of a noisy, unwieldy and unnecessarily loud torque monster? Then the video below the break by [Torque Test Channel] is just what you need!

Now, this is Hackaday, so we don’t have to go into detail about why a person might want to rip out the electric motor and adapt a 60cc 2 stroke engine in its place. Of course that’s the obvious choice. But [Torque Test Channel] isn’t just mucking about for the fun of it. No, they’re having their fun, experimenting with internal combustion engines in odd places before they are banned by 2024 in California. Now, we’re not sure if the ban includes these exact types of engines- but who needs details when you have an impact driver that can change semi tires like a NASCAR pit crew.

Looking like an overpowered weapon from a first person shoot’em up game, [Torque Test Channel]’s modified Milwaukee tests well after some modifications. Be sure to watch the video to see how it performs against an electric tool that’s even larger than itself. There are graphs, charts, and an explanation of what can be done to make even more power in the future. We’re looking forward to it!

What’s that you say? You don’t have a two stroke engine sitting around waiting to be swapped into ridiculous gadgets? Look no further than your local fridge compressor and be ready to burn some hours getting it running.

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Screenshot of Pulseview showing capture and decode of some digital channels

Need A Logic Analyzer? Use Your Pico!

March 2, 2022 by Arya Voronova 24 Comments

There’s a slew of hardware hacker problems that a logic analyzer is in a perfect position to solve. Whether you’re trying to understand why an SPI LCD screen doesn’t initialize, what’s up with your I2C bus, or determine the speed of an UART connection, you’ll really want to have a logic analyzer on hand. People have been using a Pi Pico as a logic analyzer in a pinch, and now [pico-coder] has shared a sigrok driver that adds proper support for a Pico to beloved tools like Pulseview.

The specs offered are impressive. Compared to the $10 “Saleae” clone analyzers we are so used to, this thing boasts 21 digital channels with up to 120 MHz capture speed, 3 ADC channels at up to 500 KHz, and hardware-based triggers. The GitHub repository linked above stores the driver files out-of-tree, but provides build instructions together with an easily flash-able uf2 firmware. It’s likely that you’ll soon see this driver in a stock Pulseview installation, however, given the submitter-friendly attitude we’ve witnessed on the sigrok mailing list. However, if you need a logic analyzer ASAP, you should follow the caringly offered quickstart guide.

We’ve covered Pulseview being used in combination with cheap accessible analyzers before — a must-watch if you need to get yourself up to speed on the value they provide to a hobbyist. If an oscilloscope is what you need and a smartphone is what you have, perhaps you’ll enjoy the Scoppy firmware for the Pico.

We thank [mip] for sharing this with us!