Patent Spat Leaves DJI Owing Textron $279M

May 1, 2023 by 46 Comments

Patents are the murky waters where technical jargon and legalese meet, and in this vast grey area of interpretation, DJI now owes Textron $279M.

At issue in the case were two patents issued to Textron (#8,014,909 and #9,162,752) regarding aircraft control systems for relative positioning to other vehicles and automatic hovering. The jury found that Textron’s intellectual property (IP) had been infringed and that damages amounted to $279M. DJI asserts that Textron’s patents are not valid and will appeal the decision. Appeals in patent trials are handled by the Federal Circuit and can be kicked up to the US Supreme Court, so don’t expect a final decision in the case anytime soon.

We’re not lawyers, so we won’t comment on the merits of the case, but, while it was a jury trial, it was one of many cases decided in the court of Judge Alan Albright, who has been the focus of scrutiny despite efforts to assign fewer cases to his docket amid wider efforts to stymie venue shopping in patent cases. Despite these efforts, the Western District of Texas is such a popular venue for patent cases that Berkeley offers a CEU on going to trial in Waco.

If you’re curious about more IP shenanigans, checkout the Honda mass takedown, the legality of making something similar, or why E3D patents some of their work.

Op Amp Contest: A Slice Of The ’70s

April 25, 2023 by 7 Comments

The 1970s was a great time to be an electronics hobbyist, as a whole new world of analogue integrated circuits was coming down in price while new devices would appear to tempt the would-be constructor. Magazines and project books were full of simple circuits to do all manner of fun things, including many synthesizers and sound generators.

We’re reminded of those days by [Burkhard Kainka]’s triggered sound generator, which couples an op-amp timer to another op-amp phase shift oscillator to produce a sound described as “the unwilling meowing of a cat, which does not want to be disturbed“. Yes, we did make things like this back in the day.

The timer is triggered by a few millivolts on its input, which can come from a bit of mains hum or a flash of light to an LED operating as a photodiode. This provides enough DC voltage to the input of the phase shift oscillator to start oscillation, and in turn the oscillator drives a piezo speaker. It’s a fun little project, it shows that a microcontroller isn’t always needed to make something work, and maybe those of you without the experience of a 1970s childhood can learn a little bit of analogue magic from it. Need to know op-amps better? Read our primer!

2023 Hackaday.io Op Amp Challenge

Playing 78 RPM Shellac Records: It’s Not Just About Speed

April 10, 2023 by 25 Comments

What is the difference between 78, 45, and 33 RPM records? Obviously most people would say the speed, which of course is true to a degree. But as [Techmoan] covers in a recent video, there’s a whole lot more to the playback of 78 RPM records. Especially the older type without so-called ‘microgrooves’. Even if you have a record player that can do 78 RPM speeds, you may have noticed that the sound is poor, with a lot of clicking and popping.

The primary reason for this is that on an average 78 RPM record, the groove containing the sound pattern is 3 mil (thousandth of an inch) wide, whereas the grooves on microgroove and 33/45 RPM records is a mere 1 mil wide. This difference translates into the stylus tip, which is comically undersized for the 3 mil grooves and ends up dragging somewhere in the very bottom of the groove, missing entirely out on the patterns etched higher up on the sides. This is why in the past styluses would often come in the flip-style version, as pictured above.

It’s also possible to purchase the mono, 3 mil styluses today from Audio-Technica and other well-known brands, requiring only to switch the stylus cartridge between playing sessions with different groove sizes. As [Techmoan] demonstrates in the video, the difference between a too small and just right stylus is night and day, but it reveals the second issue with playing records: equalization.

Virtually all records have some kind of equalization applied to the recorded audio, to balance out the imperfections of the recording medium. Upon playback, this effect is inverted, restoring the original signal as much as possible. Since 1954, the de facto standard has been RIAA equalization, and this is what the average record preamplifier also assumes you are using. Unfortunately, this means that for many records from around that time and before, the wrong equalization will be applied, as basically every publisher had their own standard.

In the video, [Techmoan] figures out a way to get an affordable way to playback these wide groove, 78 RPM records, and to dodge the RIAA equalization step by tapping directly into the signal from the cartridge. This would likely be a lot easier if one threw more money at the whole thing, but where is the fun in that?

Continue reading “Playing 78 RPM Shellac Records: It’s Not Just About Speed” →

ISD1700 Based Lo-Fi Sampler

April 10, 2023 by 5 Comments

Custom music instruments here at Hackaday range from wacky to poignant. OpnBeat by [Hiro Akihabara] focuses on something different: simplicity.

There are few buttons, the design and code are optimized to be straightforward and easy to modify, and the interface is slick. Eight musical keys complement three interface keys and a knob. An Arduino Nano powers the main brains of the system but the music generation comes from eight Nuvoton ISD1700s controlled over SPI by the Nano. The beautifully laid-out PCB is 110mm by 180mm (4.33″ by 7″), so cases can easily be printed on smaller FDM printers. All the switches are Cherry MX switches for the beautiful tactile feedback.

The code, PCB, and 3D case files are all available on GitHub. We love the thought that went into the design and the focus on making it easy to recreate. It might be quite as cute and simplified as this twelve-button musical macro pad, but the two together could make quite the band.

Continue reading “ISD1700 Based Lo-Fi Sampler” →

Reviving A Legend: Mamiya RB67 Repair

April 6, 2023 by 26 Comments
The damaged parts in the camera are circled in red. Original graphic is from the Mamiya service manual.

When it comes to professional medium format analog cameras, the Mamiya RB67 is among the most well-known and loved, ever since its introduction in 1970. Featuring not only support for 120 and 220 film options, but also a folding and ‘chimney’ style view finder and a highly modular body, these are just some reasons that have made it into a popular – if costly – reflex system camera even today. This is one reason why [Anthony Kouttron] chose to purchase and attempt to repair a broken camera, in the hopes of not only saving a lot of money, but also to save one of those amazing cameras from the scrap heap. Continue reading “Reviving A Legend: Mamiya RB67 Repair” →

27 Litres And 12 Cylinders, With A Practical Station Wagon Body

March 10, 2023 by 39 Comments

If you were to name one of the most famous individual road cars in the world, what would it be? If you’re British and of a Certain Age, then it’s possible your nomination is for sale, because “The Beast”, the one-off creation of [John Dodd] using a 27-litre Rolls-Royce Merlin aero engine, is up for auction. The Late Brake Show’s [Jonny Smith] has given it a drive, and we’ve pasted the resulting video below the break.

A second-hand motor isn’t usual Hackaday fare, but it’s the manner of this car’s building which we think will draw you in. [John] originally acquired somebody’s failed project featuring not a Merlin but its de-tuned derivative intended for tanks. He solved the problem of finding a transmission able to handle the immense power, and built it up with a pretty 1970s coupe body. After a fire a few years later he commissioned a new body from a dragster manufacturer, which is the wildly period estate car you’ll see in the video. It famously originally had a Rolls-Royce Cars grille, for which he ended up in court in the 1980s as the carmaker sought successfully to have it removed.

The tale of this car is one of epic scale hackery, as there is quite simply nothing else like it. It was once the world’s most powerful road car, and remains capable of well over 200 miles per hour. Sadly we couldn’t afford to buy it even if we could fit its immense length in our parking space.

Hungry for more epic British car hackery? Have we got the roadster for you!

Continue reading “27 Litres And 12 Cylinders, With A Practical Station Wagon Body” →

PCB Makes 7 Segment Displays

March 3, 2023 by 9 Comments

Of course, there’s nothing unusual about using 7-segment displays, especially in a clock. However, [Edison Science Corner] didn’t buy displays. Instead, he fabricated them from a PCB using 0805 LEDs for the segments. You can see the resulting clock project in the video below.

While the idea is good, we might have been tempted to use a pair of LEDs for each segment or used a diffuser to blur the LEDs. The bare look is nice, but it can make reading some numerals slightly confusing.

Continue reading “PCB Makes 7 Segment Displays” →