When you think of Sony, you probably think of a technology company that’s been around forever. However, as [Asianometry] points out, it really formed in the tough years after World War II. The two people behind the company’s formation were an interesting pair. One of them was a visionary engineer and one was a consummate businessman.
While it is hard to imagine today, securing a license to produce transistors was difficult in the early days. What’s worse is, even with the license, it was not feasible to use the crude devices in a radio.
Whether you have full use of your hands or not, a foot-operated keyboard is a great addition to any setup. Of course, it has to be a lot more robust than your average finger-operated keyboard, so building a keyboard into an existing footstool is a great idea.
When [Wingletang]’s regular plastic footrest finally gave up the ghost and split in twain, they ordered a stronger replacement with a little rear compartment meant to hold the foot switches used by those typing from dictation. Settling upon modifiers like Ctrl, Alt, and Shift, they went about designing a keyboard based on the ATmega32U4, which does HID communication natively.
For the switches, [Wingletang] used the stomp switches typically found in guitar pedals, along with toppers to make them more comfortable and increase the surface area. Rather than drilling through the top of the compartment to accommodate the switches, [Wingletang] decided to 3D print a new one so they could include circuit board mounting pillars and a bit of wire management. Honestly, it looks great with the black side rails.
[Peter Demchenko] wanted to use a low power TS555 in an ESR meter design. The problem is, he needed to handle significant current sink requirements for cases where the capacitor under test had a low ESR. The TS555 wasn’t up to the task.
However, [Peter] made an interesting observation. the output pin of the device can sink or source current. However, the discharge pin is exactly the same output but can only sink current.
But what if you tied them together? Using some equalizing resistors, that’s exactly what he did, and this roughly doubles the rated current sink capability. According to [Peter], you do make the circuit more sensitive to power supply variations, but that could be an acceptable trade, depending on your application.
There’s currently a significant amount of confusion around the full extent of the GPIO hardware issue in the Raspberry Pi RP2350 microcontroller, with [Ian] over at [Dangerous Prototypes] of Bus Pirate fame mentioning that deliveries of the RP2350-based Bus Pirate 5XL and 6 have been put on hold while the issue is further being investigated. Recorded in the MCU’s datasheet as erratum RP2350-E9, it was originally reported as only being related to the use of internal pull-downs, but [Ian] has since demonstrated in the primary issue ticket on GitHub that the same soft latching behavior on GPIO pins occurs also without pull-downs enabled.
Ian from Dangerous Prototypes demonstrating the RP2350-E9 issue in a Bus Pirate prototype without pull-ups.
When we first reported on this hardware bug in the RP2350’s A2 (and likely preceding) stepping there was still a lot of confusion about what this issue meant, but so far we have seen the Bus Pirate delay and projects like [AgustÃn Gimenez Bernad]’s LogicAnalyzer have opted for taking the RP2350 port out back. There are also indications that the ADC and PIO peripherals are affected by this issue, with workarounds only partially able to circumvent the hardware issue.
In the case of the Bus Pirate a potential workaround is the addition of 4.7 kOhm external pull-downs, but at the cost of 0.7 mA continuous load on the GPIO when pulled high and part of that when pulled low. It’s an ugly hack, but at the very least it might save existing boards. It also shows how serious a bug this is.
Meanwhile there are lively discussions about the issue on the Raspberry Pi forums, both on the E9 erratum as well as the question of when there will be a new stepping. The official statement by Raspberry Pi is still that ‘they are investigating’. Presumably there will be a Bx stepping at some point, but for now it is clear that the RP2350’s A2 stepping is probably best avoided.
While some byproducts recall an idyllic piece of Americana, others remind us that the past is not always so bright and cheerful. Trinitite, created unintentionally during the development of the first atomic bomb, is arguably one of these byproducts.
Whereas Fordite kept growing back for decades, all Trinitite comes from a single event — the Trinity nuclear bomb test near Alamogordo, New Mexico on July 16, 1945. Also called ‘atomsite’ and ‘Alamogordo glass’, ‘Trinitite’ is the name that stuck.
There wasn’t much interest in the man-made mineral initially, but people began to take notice (and souvenirs) after the war ended. And yes, they made jewelry out of it.
Although there is still Trinitite at the site today, most of it was bulldozed over by the US Atomic Energy Commission in 1953, who weren’t too keen on the public sniffing around.
There was also a law passed that made it illegal to collect samples from the area, although it is still legal to trade Trinitite that was already on the market. As you might expect, Trinitite is rare, but it’s still out there today, and can even be bought from reputable sources such as United Nuclear. Continue reading “Boss Byproducts: The Terrible Beauty Of Trinitite”→
Last time I tried to convince you that, if you haven’t already, you should try running your 3D printer with Klipper. There are several ways to actually make it work.
The first thing you need is something to run the Klipper host. Most people use a Raspberry Pi and if you already have one that runs OctoPrint, for example, you might well use it. Just tuck your SD card away in case you give up and install a fresh Linux system on a new card.
The Creality Sonic Pad has issues, but it does work.
However, a Pi isn’t your only option. You should be able to make it work on nearly anything that runs Linux. We’ve even seen it running on Windows under WSL. If you have an old laptop that can run Linux, that would work, too. We’ve even heard it works on a Chromebook.
The other option is to get a “pad.” Several vendors make touchscreens with some Linux single-board computer bundled together with Klipper preinstalled. For example, there is the Creality Sonic Pad, along with similar devices from other 3D printing companies.
If you decide to go that route, you might want to make sure it is easy to install your own software easily. Some pads, like the Creality unit, are notorious for having so much customization that they don’t lend themselves to upgrades unless they come from the manufacturer. In some cases, you can wipe out the stock firmware and install a normal operating system, but at that point, you could probably just buy a Pi and a touchscreen, right?
