Pi Pico Demos, Therefore It Is

A good demo, like [Linus Akesson]’s Sum Ergo Demonstrato, looks like magic to the average hacker. To normies who don’t know the limitations of the RP2350, they don’t see the big deal. To anyone who has spent any time with the chip, though, it’s a series of tricks you cannot help but be amazed by. Fortuanately for us, [Linus] isn’t actually a magician, because while a magician never reveals his tricks, [Linus] has an hour-long video explaining exactly how his demo was accomplished. We’ve embedded both the demo and the explanation below.

Even if you aren’t into YouTube, you should check out the demo video, and again– remember this is all on a Pi Pico with only the extra passives required for video-out. Then you can watch [Linus] explain how he did it, which is really best heard in his own words. There are a couple of bleeding-edge tricks on the RISC V core and peripherals that we would hate to misrepresent– especially the clever hack with the interpolator that he uses for 3D acceleration.

If this sounds a bit familiar, it’s because we were equally impressed by his Kaleidoscopico demo last year. From demos like this to 3D engines on the ESP32, its amazing what you can do on modern micros if you’re willing to hit the limits of the hardware.

Thanks to [Stephen Walters] for the tip!

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Pi Pico Puts Bluetooth Keyboards On The I2C Bus

If you’ve ever worked with I2C, you know its one of those things that makes working with modern microcontrollers such a pleasure. With a few wires and not many more lines of code, you can communicate with all sorts of hardware such as sensors, displays, and input devices. There are even I2C keyboards out there, although they tend to be a bit pokey — and not in the good way as it pertains to keyboards.

But the bt2i2c project from [Roberto Alsina] promises to improve things. With his firmware flashed to a Pi Pico W, you can establish a connection with any standard Bluetooth keyboard and have the keystrokes sent over the wire via I2C. As far as your project is concerned, the input will appear to be coming from a BlackBerry BBQ20/BBQ10 keyboard using the address 0x1F, which means that there’s already plenty of code out there to work with. While [Roberto] explains its not strictly necessary, connecting a ST7789 display to the Pi Pico over SPI will give you some visual feedback on connection status.

As microcontrollers become increasingly powerful and capable of the sort of thing we would once have done on a “real” computer, a project like this has some fascinating potential. We’ve seen a number of “writerdeck” projects running on chips like the ESP32, and it’s not hard to see the appeal of being able to easily pair your favorite Bluetooth keyboard up to one of them.

Stratasys Vs Bambu Lab: Industrial Vs Consumer ABS Showdown

The test parts being printed on the Stratasys Fortus 450mc. (Credit: My Tech Fun, YouTube)
The test parts being printed on the Stratasys Fortus 450mc. (Credit: My Tech Fun, YouTube)

Professional Stratasys FDM printers demand a pretty hefty price premium over your typical hobbyist-level machine, with the gold-plating continuing even with the special filament cartridges that you buy for some of their printers.

This raises the question of in how far this eye-watering price tag is justified, and how much is just you paying for support and the brand name. After acquiring a spool of Stratasys ABS filament via a US viewer, [Dr. Igor Gaspar] set to work to try and answer this question.

The viewer had already liberated the spool of ABS+ P430 filament from its cartridge, making it easy to use that directly with the Bambu Lab FDM printer.

To make it a fair comparison, [Igor] also needed to have a sample printed on a real Stratasys printer, for which he used a local company’s services. An interesting sidenote here is that the US viewer’s company moved away from Stratasys to Bambu Lab printers.

[Igor] was able to see his test parts being printed on the Stratasys printer, as said company is in the same city. This showed him that it took 14 hours to print the parts versus 3.5 hours on the Bambu Lab printer, suggesting that his worries about the right printing parameters for the Stratasys filament were warranted. Sussing those out was thus paramount for a fair comparison and warranted some test prints.

From a sheer aesthetic point of view the Stratasys-printed parts looked much cleaner, and their dimensional accuracy was also significantly better due to the slicer adjusting for this. Between the used Stratasys M30 and Bambu Lab ABS filaments there’s no clear winner, with both trading blows. Amusingly enough, the older Stratasys ABS type in the form of the ABS+ P430 filament performed the best of all when printed on the Bambu Lab printer at its preferred temperature setting.

Moral of the story is thus that – unless you really want to pay for that service contract – to loot old Stratasys ABS spool cartridges and use them in your hobbyist FDM printer. As [Igor] says in the conclusion, the nicer looks is probably due to them printing very thin layers, much finer than the 0.2 mm layers he used. This would also match the much longer print time and is thus something we can replicate on any FDM printer with a temperature-controlled printing environment.

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Homebrew Webcam Support For The Original Xbox

These days, we take it for granted that a video game console will have multiple USB ports. There’s even an expectation that basic peripherals such as storage devices will “Just Work” when plugged into the system — a far cry from the days when each system had its own proprietary memory card.

The original Xbox from 2001 actually had USB ports as well, it’s just that they were used for the controllers and had non-standard connectors that kept you from plugging in other devices. But a simple adapter gets you a standard USB-A port, and after that it’s just a matter of software. Like this homebrew project to get generic USB webcams working on Microsoft’s first foray into console gaming.

Well, “generic” may be pushing it a bit, as the project by [Darkone83] currently lists only two compatible cameras. The first is the Xbox Live Vision Camera, which was never intended to be used on the original Xbox and was instead an accessory for Microsoft’s follow-up console, the Xbox 360. Interestingly, the other supported camera happens to be Sony’s PS2 EyeToy. Claiming that you plugged a PS2 camera into your Xbox would have been fighting words back on the playground circa 2003, but now it’s a reality thanks to the power of open source.

Now there technically was a camera for the original Xbox, but it was only released in Japan and is quite rare. Perhaps unsurprisingly it used the same OV519 chipset as the EyeToy and later Vision Camera, and reverse engineering how the console communicated with it was critical to the development of this project.

As of right now, there’s not much practical application for this webcam driver. It just shows the image from the camera on your TV in glorious 320×240 resolution. But now that the code to make it work is out in the wild, hopefully other Xbox homebrew projects will add support for it.

Although things aren’t quite as active these days as they once were, the hacking scene for the original Xbox is the stuff of legend. If you ever see one of this gargantuan consoles at a flea market for cheap, there’s still plenty of fun to be had pushing the system outside of its comfort zone.

A small, orange 3D printer is shown on a desk with a filament dry box. The printer is printing a waving cat figurine. The printer is a CoreXY configuration, and the side panels are 3D-printed orange plastic.

3D Printing A Miniature CoreXY Printer

Although no longer so common as during the heyday of the RepRap movement, it’s easier than ever to build your own largely-printed 3D printer, with designs such as Voron’s delivering excellent quality. Nevertheless, there are still niches to be filled by new designs, such as [Alex Yu]’s mostly-printed Encore design.

The Encore uses CoreXY kinematics and linear rails for the X and Y axes. Its has no internal frame; the linear rails are mounted directly to the side panels, which were printed but provided sufficient rigidity. The printer is modular, and all the parts are designed to fit within a 225 mm print bed. The Encore itself uses a 120 mm bed, a Bowden extruder, and a lightweight Bambu-style hotend. The drive motors are NEMA 17 stepper motors, and they use sliding mounts for belt tensioning. The power supply sits behind the rods supporting the Z axis, and the controller board is in the base of the printer.

Building the printer was simple; tuning it, less so. The combination of a Bambu-type hotend with a Bowden extruder created some complications, and the hotend initially received too little cooling. [Alex] solved the cooling issues by using a stronger fan on the hotend, redesigning the ventilation shroud, and adding two inward-blowing fans along the sides of the build volume. After correcting some issues with Z-axis stability, the Encore produced some quite good-looking parts. [Alex] is still improving and documenting some aspects of the printer, but he’s uploaded his progress so far to GitHub.

We’ve seen some mostly-printed printers before, including a high-speed printer, one which printed all structural components, and one which was entirely 3D printed.

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An Unlikely Host For An 8080 Emulator

To emulate vintage microprocessor hardware, it’s normal to find a modern host that provides alongside the number-crunching grunt, sufficient physical connections to interface with its support hardware. Thus if you were shopping around it might be reasonable to pick something with a powerful core and plenty of pins. Yet to emulate an 8080, [Ted Fried] has eschewed both of these — opting for an ATtiny85, a microcontroller deficient in both pins and processing power.

This seemingly impossible feat is achieved by reducing the physical connection to an SPI bus and offloading the support functions to a Teensy. The emulation code is significantly optimized C, and includes a 128 byte cache to speed up matters. This delivers a speed claimed to be only very slightly slower than a real 8080 when booting CP/M, which is quite a feat.

We’re sure that CP/M enthusiasts will have fun with this project, and we especially like the full write-up. Going to the effort of making fake 1975 electronics magazine covers for the project really is going the extra mile, and we appreciate that. Meanwhile if you’d like one of your own, the whole thing can be found in a GitHub project.

If you’re not familiar with the 8080, maybe we can get you started.

Using Brand New NiMH Cells After Sitting 12 Years Unused

You know your batteries are old when their labels have faded. (Credit: DiodeGoneWild, YouTube)
You know your batteries are old when their labels have faded. (Credit: DiodeGoneWild, YouTube)

After finding a pack of NiMH rechargeable cells that had never been used since buying them in 2014, [DiodeGoneWild] decided to test whether they could be tossed or not. After previously testing different brand cells that had gone high internal resistance after only about five years, he wasn’t expecting much. Amazingly, the batteries not only recovered, but seems to be not that much worse off for wear.

Three of the four precharged cells still held some voltage and happily charged back up to their rated 2,000 mAh capacity basically with the first cycle. One of them read 0V initially, but was revived using the typical manual charging approach involving a bench power supply. After a few charge-discharge cycles only the deep discharged cell showed some noticeable degradation with slightly reduced capacity, but all of them read healthy internal resistance values.

What this mostly shows is that not all NiMH cells are made the same, with the Tronic ones that previously failed after a few years doing much worse than these Activ Energy cells which are apparently sold primarily at Aldi stores. Overall NiMH is a pretty robust battery chemistry, so it’s always worth it to try reviving a cell before tossing it.

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