Probes connected from a Pi Pico board to the SPI flash chip, with other end of the probes connected tot the level shifter circuit resistors

Motherboard Revived With Simplest 1.8V SPI Shifter Ever

If you have ever had to fix a modern desktop motherboard, you might have noticed that the BIOS (UEFI) SPI flash is 1.8V – which means you can no longer use a Raspberry Pi or a CH341 adapter directly, and you’d need to use a 1.8V level shifter of some sort. Now, some of us can wait for a 1.8V level shifter adapter from an online store of your choosing, but [treble] got a “BIOS flash failed” motherboard from Facebook Marketplace, and decided to make it work immediately.

She tells us a story about reviving the motherboard, and there’s one thing she shows that is interesting in particular – a very simple way to level shift 3.3V signals from a serprog-flashed Pi Pico down to the 1.8V that the flash chip required, something you are guaranteed to be able to build out of the parts in your parts bin, only requiring nine resistors and an NPN transistor. If you ever need to reflash BIOS on a modern motherboard, take note. As for 1.8V rail, she ended up tapping the 1.8V power pin of the SPI chip the motherboard itself to power the chip while programming it.

In the end, after swapping the two BIOS chips places and fixing a broken trace mishap, the motherboard booted, and works wonderfully to this day, a much-needed upgrade to [treble]’s toolkit that allows her to do RISC-V cross-compiling with ease nowadays. This is not the first time we see people reflash modern boards with 1.8V chips – if you want to learn more, check out this incredibly detailed writeup! Need to do some further debugging? Use your Pico as a POST card!

A map of the world with continents in light grey and countries outlined in dark grey. A nuber of yellow and grey circles with cartoon factories on them are connected with curved lines reminiscent of airplane flight paths. The lines have seemingly-arbitrary binary ones and zeros next to them. All of the grey factories are in the Americas, likely since IoP is currently focused on Africa and Europe.

Internet Of Production Alliance Wants You To Think Globally, Make Locally

With the proliferation of digital fabrication tools, many feel the future of manufacturing is distributed. It would certainly be welcome after the pandemic-induced supply chain kerfuffles from toilet paper to Raspberry Pis. The Internet of Production Alliance (IoP) is designing standards to smooth this transition. [via Solarpunk Presents]

IoP was founded in 2016 to build the infrastructure necessary to move toward a global supply chain based on local production of goods from a global database of designs instead of the current centralized model of production with closed designs. Some might identify this decentralization as part of the Fourth Industrial Revolution. They currently have developed two standards, Open Know-Where [PDF] and Open Know-How.

Open Know-Where is designed to help locate makerspaces, FabLabs, and other spaces with the tools and materials necessary to build a thing. The sort of data collected here is broken down in to five categories: manufacturing facility, people, location, equipment, and materials. Continue reading “Internet Of Production Alliance Wants You To Think Globally, Make Locally”

No Inductors Needed For This Simple, Clean Twin-Tee Oscillator

If there’s one thing that amateur radio operators are passionate about, it’s the search for the perfect sine wave. Oscillators without any harmonics are an important part of spectrum hygiene, and while building a perfect oscillator with no distortion is a practical impossibility, this twin-tee audio frequency oscillator gets pretty close.

As [Alan Wolke (W2AEW)] explains, a twin-tee oscillator is quite simple in concept, and pretty simple to build too. It uses a twin-tee filter, which is just a low-pass RC filter in parallel with a high-pass RC filter. No inductors are required, which helps with low-frequency designs like this, which would call for bulky coils. His component value selections form an impressively sharp 1.6-kHz notch filter about 40 dB deep. He then plugs the notch filter into the feedback loop of an MCP6002 op-amp, which creates a high-impedance path at anything other than the notch filter frequency. The resulting sine wave is a thing of beauty, showing very little distortion on an FFT plot. Even on the total harmonic distortion meter, the oscillator performs, with a THD of only 0.125%.

This video is part of [Alan]’s “Circuit Fun” series, which we’ve really been enjoying. The way he breaks complex topics into simple steps that are easy to understand and then strings them all together has been quite valuable. We’ve covered tons of his stuff, everything from the basics of diodes to time-domain reflectometry.

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Back To Basics With A 555 Deep Dive

Many of us could sit down at the bench and whip up a 555 circuit from memory. It’s really not that hard, which is a bit strange considering how flexible the ubiquitous chip is, and how many ways it can be wired up. But when was the last time you sat down and really thought about what goes on inside that little fleck of silicon?

If it’s been a while, then [DiodeGoneWild]’s back-to-basics exploration of the 555 is worth a look. At first glance, this is just a quick blinkenlights build, which is completely the point of the exercise. By focusing on the simplest 555 circuits, [Diode] can show just what each pin on the chip does, using an outsized schematic that reflects exactly what’s going on with the breadboarded circuit. Most of the demos use the timer chip in free-running mode, but circuits using bistable and monostable modes sneak in at the end too.

Yes, this is basic stuff, but there’s a lot of value in looking at things like this with a fresh set of eyes. We’re impressed by [DiodeGoneWild]’s presentation; while most 555 tutorials focus on component selection and which pins to connect to what, this one takes the time to tell you why each component makes sense, and how the values affect the final result.

Curious about how the 555 came about? We’ve got the inside scoop on that.

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Canada Bans Flipper Zero Over What It Imagines It Does

Canada’s intent to ban the Flipper Zero wireless tool over car thefts is, on the one hand, an everyday example of poorly researched government action. But it may also be a not-so-subtle peek into the harm misinformation online can cause by leading to said government action.

The Government of Canada recently hosted a national summit on combatting vehicle theft, and Minister of Innovation, Science and Industry François-Philippe Champagne proudly declared immediate actions being taken to ban devices used to steal vehicles by wirelessly bypassing keyless entry, the Flipper Zero being specifically named as one such device.

And yet, defeating a rolling code keyless entry system is a trick a device like the Flipper Zero simply cannot pull off. (What cars have such a system? Any car made in roughly the last thirty years, for a start.)

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Target Lifting Mechanism Goes Wireless

“WARNING: DO NOT Hammer on this mechanism” sounds like the start of a side quest. A quest is exactly what [CelGenStudios] started when he came upon a strange box with this message.

The military identification tag was printed “Target Holding Mechanism, M31A1”, along with some other information. It also informed the reader that the device weighed 70lbs (31.75kg). Something carrying that much mass just had to be good.

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A Tube Tester Laid Bare

There’s still a mystique around vacuum tubes long after they were rendered obsolete by solid state devices, and many continue to experiment with them. They can be bought new, but most of us still come to them through the countless old tubes that still litter our junk boxes. But how to know whether your find is any good? [Rob’s Fixit Shop] took a look at a tube tester, once a fairly ubiquitous item, but now a rare sight.

To look at it’s a box with an array of tube sockets, a meter, and a set of switches to set the pinout for the tube under test. We expected it to use a common-cathode circuit, but instead it measures leakage between the grid and the other electrodes, a measure of how good the vacuum in the device is. In a worrying turn this instrument can deliver an electric shock, something he traces to a faulty indicator light leading to the chassis. We are however still inclined to see it as anything but safe, because the lack of mains isolation still exposes the grid to unwary fingers.

All in all though it’s an interesting introduction to an unusual instrument, and given a suitable isolating transformer we wouldn’t mind the chance to have one ourselves. If you need to test a tube and don’t have one of these, don’t worry. It’s possible to roll your own.

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