DIY Split Keyboard Made With A Saw

Split keyboards are becoming more popular, but because they’re still relatively niche, they can be rather expensive if you want to buy one. So why not make your own? Sure, you could assemble one from a kit, but why not take a cheap mechanical keyboard, slice it in half and just waves hands connect the two halves back together? If this thought appeals to you, then [nomolk]’s literal hackjob video should not be ignored. Make sure to enable English subtitles for the Japanese-language video.

Easy split keyboard tip: just reconnect both halves... (Credit: nomolk, YouTube)
Easy split keyboard tip: just reconnect both halves… (Credit: nomolk, YouTube)

In it, the fancy (but cheap) mechanical keyboard with Full RGBâ„¢ functionality is purchased and tested prior to meeting its demise. Although the left side with the cable and controller still works, the right side now needs to be connected, which is where a lot of tedious wires have to be soldered to repair traces.

Naturally this will go wrong, so it’s important to take a (sushi) break and admire the sunset before hurling oneself at the tracing of faulty wiring. This process and the keyboard matrix is further detailed on the blog entry (in Japanese) for this process.

Although this was perhaps easier than the other split keyboard project involving a membrane keyboard, this tongue-in-cheek project demonstrates the limits of practicality with this approach even if it could be cleaned up more with fancier wiring.

We give it full points for going the whole way, however, and making the keyboard work again in the end.

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AMSAT-OSCAR 7: The Ham Satellite That Refused To Die

When the AMSAT-OSCAR 7 (AO-7) amateur radio satellite was launched in 1974, its expected lifespan was about five years. The plucky little satellite made it to 1981 when a battery failure caused it to be written off as dead. Then, in 2002 it came back to life. The prevailing theory being that one of the cells in the satellites NiCd battery pack, in an extremely rare event, failed open — thus allowing the satellite to run (intermittently) off its solar panels.

In a recent video by [Ben] on the AE4JC Amateur Radio YouTube channel goes over the construction of AO-7, its operation, death and subsequent revival are covered, as well as a recent QSO (direct contact).

The battery is made up of multiple individual cells.

The solar panels covering this satellite provided a grand total of 14 watts at maximum illumination, which later dropped to 10 watts, making for a pretty small power budget. The entire satellite was assembled in a ‘clean room’ consisting of a sectioned off part of a basement, with components produced by enthusiasts associated with AMSAT around the world. Onboard are two radio transponders: Mode A at 2 meters and Mode B at 10 meters, as well as four beacons, three of which are active due to an international treaty affecting the 13 cm beacon.

Positioned in a geocentric LEO (1,447 – 1,465 km) orbit, it’s quite amazing that after 50 years it’s still mostly operational. Most of this is due to how the satellite smartly uses the Earth’s magnetic field for alignment with magnets as well as the impact of photons to maintain its spin. This passive control combined with the relatively high altitude should allow AO-7 to function pretty much indefinitely while the PV panels keep producing enough power. All because a NiCd battery failed in a very unusual way.

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Inside A Fake WiFi Repeater

Fake WiFi repeater with a cheap real one behind it. (Credit: Big Clive, YouTube)
Fake WiFi repeater with a cheap real one behind it. (Credit: Big Clive, YouTube)

Over the years we have seen a lot of fake electronics, ranging from fake power saving devices that you plug into an outlet, to fake car ECU optimizers that you stick into the OBD port. These are all similar in that they fake functionality while happily lighting up a LED or two to indicate that they’re doing ‘something’. Less expected here was that we’d be seeing fake WiFi repeaters, but recently [Big Clive] got his hands on one and undertook the arduous task of reverse-engineering it.

The simple cardboard box which it comes in claims that it’s a 2.4 GHz unit that operates at 300 Mbps, which would be quite expected for the price. [Clive] obtained a real working WiFi repeater previously that did boast similar specifications and did indeed work. The dead giveaway that it is a fake are the clearly fake antennae, along with the fact that once you plug it in, no new WiFi network pops up or anything else.

Inside the case – which looks very similar to the genuine repeater – there is just a small PCB attached to the USB connector. On the PCB are a 20 Ohm resistor and a blue LED, which means that the LED is being completely overdriven as well and is likely to die quite rapidly. Considering that a WiFi repeater is supposed to require a setup procedure, it’s possible that these fake repeaters target an audience which does not quite understand what these devices are supposed to do, but they can also catch more informed buyers unaware who thought they were buying some of the cheap real ones. Caveat emptor, indeed.

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General Fusion Claims Success With Magnetized Target Fusion

It’s rarely appreciated just how much more complicated nuclear fusion is than nuclear fission. Whereas the latter involves a process that happens all around us without any human involvement, and where the main challenge is to keep the nuclear chain reaction within safe bounds, nuclear fusion means making atoms do something that goes against their very nature, outside of a star’s interior.

Fusing helium isotopes can be done on Earth fairly readily these days, but doing it in a way that’s repeatable — bombs don’t count — and in a way that makes economical sense is trickier. As covered previously, plasma stability is a problem with the popular approach of tokamak-based magnetic confinement fusion (MCF). Although this core problem has now been largely addressed, and stellarators are mostly unbothered by this particular problem, a Canadian start-up figures that they can do even better, in the form of a nuclear fusion reactors based around the principle of magnetized target fusion (MTF).

Although General Fusion’s piston-based fusion reactor has people mostly very confused, MTF is based on real physics and with GF’s current LM26 prototype having recently achieved first plasma, this seems like an excellent time to ask the question of what MTF is, and whether it can truly compete billion-dollar tokamak-based projects.

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Why Are Micro Center Flash Drives So Slow?

Every year, USB flash drives get cheaper and hold more data. Unfortunately, they don’t always get faster. The reality is, many USB 3.0 flash drives aren’t noticeably faster than their USB 2.0 cousins, as [Chase Fournier] found with the ultra-cheap specimens purchased over at his local Micro Center store.

Although these all have USB 3.0 interfaces, they transfer at less than 30 MB/s, but why exactly? After popping open a few of these drives the answer appears to be that they use the old-style Phison controller (PS2251-09-V) and NAND flash packages that you’d expect to find in a USB 2.0 drive.

Across the 32, 64, and 256 GB variants the same Phison controller is used, but the PCB has provisions for both twin TSOP packages or one BGA package. The latter package turned out to be identical to those found in the iPhone 8. Also interesting was that the two 256 GB drives [Chase] bought had different Phison chips, as in one being BGA and the other QFP. Meanwhile some flash drives use eMMC chips, which are significantly faster, as demonstrated in the video.

It would seem that you really do get what you pay for, with $3 “USB 3.0” flash drives providing the advertised storage, but you really need to budget in the extra time that you’ll be waiting for transfers.

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Teardown Of Casio Credit Card-Sized Radio

These days we don’t get too fussed about miniaturized electronics, not when you can put an entire processor and analog circuitry on a chip the size of a grain of sand. Things were quite different back in the 1980s, with the idea of a credit card-sized radio almost preposterous. This didn’t stop the engineers over at Casio from having a go at this and many other nutty ideas, with [Matt] from Techmoan having a go at taking one of these miniaturized marvels apart.

The Casio FM Stereo radio in happier days. (Credit: Techmoan, YouTube)

On the chopping block is the FM stereo device that was featured in a previous episode. Out of the four credit card-sized radios in that video, the one with the rechargeable battery (obviously) had ceased to work, so it was the obvious choice for a teardown. This mostly meant peeling off the glued-on top and bottom, after which the circuitry became visible.

In addition to the battery with a heavily corroded contact, the thin PCB contains a grand total of three ICs in addition to the analog circuitry. These were identified by [Spritetm] as an AM/FM tuner system IC (TA7792), an FM PLL MPX (TA7766AF) and a headphone amplifier (TA7767F), all of them manufactured by Toshiba.

Although [Matt] reckons this was a destructive teardown, we’re looking forward to the repair video where a fresh cell is soldered in and the case glued back together. Continue reading “Teardown Of Casio Credit Card-Sized Radio”

Build Customized Raspberry Pi OS Images With Rpi-image-gen

Recently Raspberry Pi publicly announced the release of their new rpi-image-gen tool, which is advertised as making custom Raspberry Pi OS (i.e. Debian for specific Broadcom SoCs) images in a much more streamlined fashion than with the existing rpi-gen tool, or with third-party solutions. The general idea seems to be that the user fetches the tool from the GitHub project page, before running the build.sh script with parameters defining the configuration file and other options.

The main advantage of this tool is said to be that it uses binary packages rather than (cross-)compiling, while providing a range of profiles and configuration layers to target specific hardware & requirements. Two examples are provided in the GitHub project, one for a ‘slim’ project, the other for a ‘webkiosk‘ configuration that runs a browser in a restricted (Cage) environment, with required packages installed in the final image.

Looking at the basic ‘slim’ example, it defines the INI-style configuration in config/pi5-slim.cfg, but even when browsing through the main README it’s still somewhat obtuse. Under device it references the mypi5 subfolder which contains its own shell script, plus a cmdline.txt and fstab file. Under image it references the compact subfolder with another bunch of files in it. Although this will no doubt make a lot more sense after taking a few days to prod & poke at this, it’s clear that this is not a tool for casual users who just want to quickly put a custom image together.

This is also reflected in the Raspberry Pi blog post, which strongly insinuates that this is targeting commercial & industrial customers, rather than hobbyists.