ESP32 Virtual Machine Lets You Change Programs On The Fly

February 27, 2022 by 30 Comments

Often, reprogramming a microcontroller involves placing it in reset, flashing the code, and letting it fire back up. It usually involves shutting the chip down entirely. However, [bor0] has built a virtual machine that runs on the ESP32, allowing for dynamic program updates to happen.

The code is inspired by the CHIP-8, a relatively ancient interpreter that had some gaming applications. [bor0] had already created a VM simulating the CHIP-8, and repurposed it here, taking out the gaming-related drawing instructions and replacing them with those that control IO pins. Registers have also been changed to 16 bits for added flexibility and headroom.

It’s probably not something with immediate ground-breaking applications for most people, but it’s a different way of working with and programming the ESP32, and that’s pretty neat.

The ESP32 is a powerful chip, too, as we all know – and it makes a great 8-bit emulator to boot. Sound off in the comments with your thoughts on what would make a killer application for the ESP32 VM!

[Thanks to satancete for the tip!]

Two clothespin hacks mentioned in the article, side-by-side.

Need To Probe Circuits? Remember About Clothespins!

February 27, 2022 by 9 Comments

After browsing Thingiverse for some printable PCB probe designs, [Henry York] looked around and found a wooden clothespin on his desk. After some collaboration between his 3D printer and his CNC, Henry graced us with a nifty helper tool design that many of us might want to make in a pinch – a small, cheap and easy to make PCB probe, for circuits where soldering and headers are out of the question. Small magnets are glued to the clothespin, holding it flush to a magnetizable work surface (aka a toaster tray), and the probing itself is done by an extruder cleaning needle end. 3D printer and Edge.Cuts files are shared with us – thanks to Henry’s helpfulness, it should be easy to repeat if ever needed!

[Tyler Rosonke] (@zonksec) was programming a batch of badges and needed a reliable way to attach to a 6-pin ISP header – without actually soldering to the badges before they’re handed out to participants! A clothespin materialized nearby yet again – most likely, channeled from a different dimension by the spirit of numerous acrylic-cast pogopin-toothed clip-on tools we scroll by on Aliexpress. With a small perfboard piece and a bunch of pogopins jumping out of their respective drawers, it became no longer necessary to hold a bundle of male-ended pin header wires at a weird angle while nervously looking at the avrdude progress bar. This ended up saving a whole lot of time, something that’s always best spent on adding insidious bugs to the badge firmware (as well as, perhaps, easter eggs).

We’d love to hear about all the small hacks and improvements that you, hackers in our audience, invent. Whether it’s reusing a SOIC flashing clip for ISP programming or printing yourself an octopus-like contraption with needle probes, you should share it with us!

Image showing differences between WS2815 and WS2813 LED strips - the WS2815 strip lighting is more uniform throughout the strip's length.

Teaching You Everything You Might Have Missed About Addressable LEDs

February 27, 2022 by 11 Comments

Often, financial motivation results in people writing great educational material for hackers. Such is absolutely the case with this extensive documentation blog post on addressable LEDs by [DeRun]. This article could very be named “Addressable LEDs 101”, and it’s a must-scroll-through for anyone, whether you’re a seasoned hacker, or an artist with hardly any technical background and a desire to put LEDs in your creations.

This blog post is easy to read, painting a complete picture of what you can expect from different addressable LED types, and with apt illustrations to boot. Ever wonder which one of the addressable strips you should get from your retailer of choice, and what are the limitations of any specific type? Or, perhaps, you’d like to know – why is it that a strip with a certain LED controller is suspiciously cheap or expensive? You’re more than welcome to, at least, scroll through and fill into any of your addressable LED knowledge gaps, whether it’s voltage drops, color accuracy differences, data transfer protocol basics or dead LED failsafes.

Addressable LEDs have a special place in our hearts, it’s as if the sun started shining brighter after we’ve discovered them… or, perhaps, it’s all the LEDs we are now able to use. WS2812 is a staple of the addressable LED world, which is why we see them even be targets of both clone manufacturers and patent trolls. However, just like the blog post we highlight today mentions, there’s plenty of other options. Either way do keep coming cover a new addressable LED-related hack, like rewriting their drivers to optimize them, or adding 3.3V compatibility with just a diode.

We thank [Helge] for sharing this with us!

S15351 tube transmitter

Retro And New Tech Combine In This Hybrid Ham Transmitter

February 27, 2022 by 9 Comments

We’ve said it before and we’ll say it again: the best part about holding an amateur radio license is that it lets you build and use your own transmitting equipment. Hams have been doing this for more than a century — indeed, it was once the only way to get on the air — using whatever technology was available. But the mix of technologies in this low-power transmitter for the 80-meter band is something you don’t see every day.

As ham [Helge Fykse (LA6NCA)] describes in the video below, the project began when he came into possession of a bonanza of vacuum tubes — 12A6 tetrodes, specifically. The new-old-stock tubes were perfect for an RF power amplifier, but that left the problem of what to use for an oscillator. [Helge] chose to meld the old with the new and used oscillator board that he designed. The board has an ATmega88 microcontroller and an Si5351 oscillator, along with a 3V3 regulator to let the module run on 12 volts. And for a nice retro touch, [Helge] put the board in a 3D printed case that looks like an old-fashioned quartz crystal.

There are some other nice design touches here too. A low-pass filter cleans up the harmonics of the oscillator’s 3.5-MHz square wave output before feeding it to the amplifier, in a nod to proper spectrum hygiene. The primary for the amp’s air-core output transformer is hand-wound, with 3D printed spacers to keep the winding neat and even. The tuning process shown below is interesting, and the transmitter was used to make a solid contact with another ham about 100 km away. And we really liked the look of [Helge]’s shack, stuffed as it is with gear both old and new.

We’ve personally tried the Si5351 for QRP transmitters before, but this blend of the old and new really makes us want to find some tubes and get to playing.

Continue reading “Retro And New Tech Combine In This Hybrid Ham Transmitter” →

screenshow showing the supposed AllSpice interface. It resembles the GitHub interface, and shows a pull request open to add some ESD protection to a device.

AllSpice Building A Hardware Development Ecosystem For Companies

February 27, 2022 by 7 Comments

In our “hardware development gets serious” news, we’ve recently learned about AllSpice, a startup building hardware development collaboration infrastructure for companies. Hardware developers are great at building hardware tools for themselves, but perhaps not always so when it comes to software, and AllSpice aims to fill that gap at the “hardware company” level. Nowadays, what commonly happens is that software development tools and integrations are repurposed for hardware needs, and the results aren’t always as stellar as they get in the software world. In other words, AllSpice is learning from the positive outcomes of software industry and building a platform that takes the best parts from these tools, aiming to get to similarly positive outcomes in areas where currently hardware team experiences are lacking.

What AllSpice is building seems to be an umbrella platform designed to augment, integrate and hook into a slew of different already-developed platforms like GitHub, GitLab, Jira (and some other ones), and add much-needed features that large-scale hardware developers can’t afford to maintain and develop themselves. “Design review by screenshot” isn’t unheard of in hardware circles, and likely a thing that everyone of us with hardware collaboration experience has partaken in. On a company scale, there’s a myriad of hardware-related problems like that to solve and polish over.

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Bionic Implants Can Go Obsolete And Unsupported, Too

February 26, 2022 by 33 Comments

When a piece of hardware goes unsupported by a company, it can be frustrating. Bugs may no longer get fixed, or in the worst cases, perfectly good hardware can stop working entirely as software licences time out. Sadly, for a group reliant on retinal implants from company Second Sight, the company has since stopped producing and supporting the devices that give them a crude form of bionic sight.

The devices themselves consist of electrodes implanted into the retina, which can send signals to the nervous system which appear as spots of light to the user. A camera feed is used to capture images which are then translated into signals sent to the retinal electrodes. The results are low-resolution to say the least, and the vision supplied is crude, but it gives users that are blind a rudimentary sense that they never had before. It’s very much a visual equivalent to the cochlear implant technology.

The story is altogether too familiar; Second Sight Medical Products came out with a cutting-edge device, raised money and put it out into the world, only to go bankrupt down the road, leaving its users high and dry. Over 350 people have the implants fitted in one eye, while one Terry Byland is the sole person to have implants in both his left and right eyeballs. Performance of the device was mixed, with some users raving about the device while others questioned its utility.

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$60 PC Oscilloscope Review

February 26, 2022 by 45 Comments

Owning an oscilloscope is a real gamechanger and these days, scopes are more capable and less expensive than ever before. However, there is a big difference between scopes that cost several hundred dollars which are usually quite good and many of the very inexpensive — below $100 — instruments that are often — but not always — little more than toys. [Adrian] looks at a PC-based scope from Hantek that costs about $60. Is it a toy? Or a useful tool? He answers the question in the video below.

The Hantek 6022BE sports two channels with a 20 MHz bandwidth and 48 million samples per second. The device included probes, too. Of course, you also need a PC, although there is apparently third-party software for Android if you don’t want to lug a laptop around.

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