Chip Shortage Engineering: Misusing DIP Packages

October 3, 2023 by Tom Nardi 57 Comments

After years of seeing people showing off and trading their badge Simple Add-Ons (SAOs) at Supercon, this year I finally decided to make one myself. Now for a first attempt, it would have been enough to come up with some cool PCB art and stick a few LEDs on it. But naturally I started with a concept that was far more ambitious than necessary, and before long, had convinced myself that the only way to do the thing justice was to have an onboard microcontroller.

My first thought was to go with the venerable ATtiny85, and since I already had a considerable stock of the classic eight-pin DIP MCUs on hand, that’s what I started prototyping with. After I had something working on the breadboard, the plan was to switch over to the SOIC-8 version of the chip which would be far more appropriate for something as small as an SAO.

Unfortunately, that’s where things got tricky. I quickly found that none of the major players actually had the SMD version of the chip in stock. Both DigiKey and Mouser said they didn’t expect to get more in until early 2024, and while Arrow briefly showed around 3,000 on hand, they were all gone by the time I checked back. But that was only half the problem — even if they had them, $1.50 a piece seems a hell of a lot of money for an 8-bit MCU with 8K of flash in 2023.

The whole thing was made all the more frustrating by the pile of DIP8 ATtiny85s sitting on the bench, mocking me. Under normal circumstances, using them in an SAO wouldn’t really be a problem, but eight hand-soldered leads popping through the front artwork would screw up the look I had in mind.

While brooding over the situation my eyes happened to fall on one of the chips I had been fiddling with, it’s legs badly bent from repeated trips through the programmer. Suddenly it occurred to me that maybe there was a way to use the parts I already had…

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At Last! Faster OpenSCAD Rendering Is On The Horizon

October 3, 2023 by Jenny List 29 Comments

Known as “The Programmers Solid 3D CAD Modeller”, OpenSCAD is used by many people for whom writing code comes more naturally than learning a fiddly user interface. It’s a very capable piece of software, but regular users will tell you that it can be rather slow when it comes to rendering your work. We’re very pleased to see that a fix for this has been produced courtesy of [@ochafik], can now be found as an experimental feature in nightly builds, and will in due course no doubt find its way to official releases.

Despite a modern computer invariably having a multi-core architecture, it might surprise you to find that OpenSCAD wasn’t able to take advantage of this previously. The above-linked thread spans over a decade of experimenting and contains some fascinating discussions if you’re prepared to wade through it, and culminates a few weeks ago in the announcement of the new feature giving access to multiple CPUs. We don’t have it yet, but it’s great to know it’s in the works and we’re looking forward to render time involving considerably less of a wait.

So many OpenSCAD projects have passed through these pages over the years, it’s safe to say that it has a significant user base among Hackaday readers. It’s still something an AI hasn’t mastered yet though.

Thanks [pca006132] for the tip.

Femtosecond Laser Clones Itself In Glass

October 3, 2023 by Maya Posch 4 Comments

When researchers at the Galatea laboratory in Switzerland set out to create a femtosecond laser in glass they weren’t certain it was going to work. To be precise, their goal was to create a femtosecond laser cavity using carefully aligned optics. Rather than using the traditional, discrete method, they used a commercial femtosecond laser to carve out the elements of the optical cavity in glass. The choice for glass came down to the low thermal expansion of this material, and it being transparent for the optical frequencies being targeted.

Generic concept of an “all-glass” optical device, with the various stages of fabrication. (Credit: Antoine Delgoffe et al., 2023)

Even after using the existing laser to create the rough laser cavity, the resulting optical mirrors were not aligned properly, but this was all part of the plan.

By also adding slots that created a flexure mechanism, brief laser pulses could be used to gradually adjust the mirrors to create the perfect alignment. During subsequent testing of the newly created laser cavity it was found to be operating as expected. The original femtosecond laser had successfully created a new femtosecond laser.

Perhaps the most tantalizing aspect of this research is that this could enable much faster and ultimately cheaper production of such laser systems, especially once the tedious and currently completely manual mirror alignment procedure is automated. In addition, it raises the prospect of producing other types of optics including splitters and guides in a similar manner.