Retrotechtacular: Studio Camera Operation, The BBC Way

November 26, 2023 by Dan Maloney 11 Comments

If you ever thought that being a television camera operator was a simple job, this BBC training film on studio camera operations will quickly disabuse you of that notion.

The first thing that strikes you upon watching this 1982 gem is just how physical a job it is to stand behind a studio camera. Part of the physicality came from the sheer size of the gear being used. Not only were cameras of that vintage still largely tube-based and therefore huge — the EMI-2001 shown has four plumbicon image tubes along with tube amplifiers and weighed in at over 100 kg — but the pedestal upon which it sat was a beast as well. All told, a camera rig like that could come in at over 300 kg, and dragging something like that around a studio floor all day under hot lights had to be hard. It was a full-body workout, too; one needed a lot of upper-body strength to move the camera up and down against the hydropneumatic pedestal cylinder, and every day was leg day when you had to overcome all that inertia and get the camera moving to your next mark.

Operating a beast like this was not just about the bull work, though. There was a lot of fine motor control needed too, especially with focus pulling. The video goes into a lot of detail on maintaining a smooth focus while zooming or dollying, and shows just how bad it can look when the operator is inexperienced or not paying attention. Luckily, our hero Allan is killing it, and the results will look familiar to anyone who’s ever seen any BBC from the era, from Dr. Who to I, Claudius. Shows like these all had a distinctive “Beeb-ish” look to them, due in large part to the training their camera operators received with productions like this.

There’s a lot on offer here aside from the mechanical skills of camera operation, of course. Framing and composing shots are emphasized, as are the tricks to making it all look smooth and professional. There are a lot of technical details buried in the video too, particularly about the pedestal and how it works. There are also two follow-up training videos, one that focuses on the camera skills needed to shoot an interview program, and one that adds in the complications that arise when the on-air talent is actually moving. Watch all three and you’ll be well on your way to running a camera for the BBC — at least in 1982.

Continue reading “Retrotechtacular: Studio Camera Operation, The BBC Way” →

Double-Dose Of AI Turns Daily Tasks Into Works Of Art

November 25, 2023 by Dan Maloney 11 Comments

Not so long ago, “Magic Mirror” builds were all the rage, and we have to admit getting out daily reminders and newsfeeds on an LCD display sitting behind a partially reflective mirror is not without its charms. But styles ebb and flow, so we don’t see too many of those builds anymore. This e-ink daily calendar reminder hearkens back to those Magic Mirrors, only with a double twist of AI.

This project is the work of [Ilkka Turunen], and right up front we’ll say the results are just gorgeous. A lot of that has to do with the 10.3″ e-ink display used, but more with the creative use of not one but two machine learning systems. The first is ChatGPT, which [Ilkka] uses to parse the day’s online calendar entries and grab the most significant events to generate a prompt for DALL-E. The generated DALL-E prompt has specific instructions that guide the style of the image, which honestly is where most of the artistry lies. [Ilkka]’s aesthetic choices, like suggesting that the images look like a 19th-century lithograph or a satirical comic from a turn-of-the-(last)-century newspaper. The prompt is then sent off to DALL-E for rendering, and the resulting image is displayed.

It has to be said that the prompts that ChatGPT generates based on the combination of [Ilkka]’s aesthetic preferences and the random events of the day are strikingly complex. The chatbot really seems to be showing some imagination these days; DALL-E is no slouch either in turning those words into images.

Like the idea of an e-ink daily reminder but prefer a less artistic presentation? This should help.

Continue reading “Double-Dose Of AI Turns Daily Tasks Into Works Of Art” →

Fail Of The Week: This Flash Drive Will NOT Self-Destruct In Five Seconds

November 25, 2023 by Dan Maloney 49 Comments

How hard can it be to kill a flash drive? Judging by the look of defeat on [Walker]’s face in the video below, pretty darn hard.

To bring you up to speed, and to give the “Mission: Impossible” reference in the title some context, it might be a good idea to look over our earlier coverage of [Walker]’s Ovrdrive project. It started way back in 2022 with the idea that some people might benefit from a flash drive that could rapidly and covertly render the data stored on it, err, “forensically unavailable.” This would require more than just erasing the data, of course, so [Walker] began looking at ways to physically kill a memory chip. First up was a voltage doubler to apply voltage much greater than the absolute maximum rating of 4.6 V for any pin on the chip. That corrupted some files on the flash chip, enough of a win to proceed to a prototype that actually succeeded in releasing the Magic Smoke.

But sadly, that puff of smoke ended up being a fluke. [Walker] couldn’t repeat the result, at least not with the reliability required by people for whom data privacy is literally a life-or-death matter. To increase the odds of a kill, he came up with an H-bridge circuit to reverse the polarity of the memory chip’s supply. Surely that would kill the chip, and from the thermal camera images, it sure looked promising. But apparently, even 167°C isn’t enough to forensically disable the chip, which kind of makes sense from the point of view of reflow survivability.

What’s next for [Walker]? He says he’s going to team up his overvoltage and reverse-polarity methods for one last shot, but after that, he’s about out of reasonable options. Sure, a thermite charge or a vial of superacid would do the trick, but neither is terribly covert. If you’re going to go that way, you might as well just buy a standard flash drive and throw it in the microwave or a blender. And we need to remember that this may be something the drive’s owner needs to do with jack-booted thugs kicking in the door, or possibly at gunpoint. It wouldn’t do to be too conspicuous under such circumstances. That’s why we like the “rapid power cycling” method of triggering the drive’s self-destruct sequence; it could easily be disguised as shaking hands in a stressful situation.

Who knew that memory chips were this robust? Kudos to [Walker] for getting the project as far as he did, and we’re still rooting for him to make it work somehow.

Continue reading “Fail Of The Week: This Flash Drive Will NOT Self-Destruct In Five Seconds” →

The Other Kind Of Static Hazard To Your Logic Circuits

November 24, 2023 by Dan Maloney 21 Comments

We’ve all heard of the dangers of static electricity when dealing with electronics, and we all take the proper precautions when working with static-sensitive components — don’t we? But as much as we fear punching an expensive hole in a chip with an errant spark, electrostatic discharge damage isn’t the only kind of static hazard your digital designs can face.

To be fair, the static hazard demonstrated by [Shane Oberloier] in the video below isn’t really an electrostatic problem. “Static” in this case refers to when a change to an input of a logic circuit gives an unexpected output until the circuit stabilizes. The circuit shown is pretty simple, with three inputs going into a combination of AND and NOT gates before going into an OR gate. The static hazard manifests as a glitch in the output when the middle input line’s logical state is toggled; according to the circuit’s truth table, the output shouldn’t change under these conditions, but the oscilloscope clearly captures a high-low-high blip. [Dr. Shane]’s explanation of why this happens makes perfect sense: the inverter on that input line has a brief but non-zero propagation time, putting the whole circuit in an ambiguous state before finally settling down to the correct output value.

So how do you fix something like this? This gets into the Boolean weeds a bit, and we won’t pretend to fully understand it, but at least for this case, [Dr. Shane] was able to add a single AND gate to sum the two other inputs and pipe the output into another input of the OR gate. That has the effect of canceling out the race condition caused by the inverter, but at the expense of a more complicated circuit, of course.

We found this to be a fascinating and informative discussion of a potential pitfall in logic design. But, if you still want to see some MOSFETs executed with static electricity, who are we to object?

Continue reading “The Other Kind Of Static Hazard To Your Logic Circuits” →

Simple CMOS Circuit Allows Power And Data Over Twisted-Pair Wiring

November 21, 2023 by Dan Maloney 29 Comments

If you need to send data from sensors, there are plenty of options, including a bewildering selection of wireless methods. Trouble is, most of those protocols require a substantial stack of technology to make them work, and things aren’t much easier with wired sensors either. It doesn’t have to be that complicated, though, as this simple two-wire power-and-data interface demonstrates.

As with all things electronic, there are tradeoffs, which [0033mer] addresses in some detail in the video below. The basic setup for his use case is a PIC-based sensor — temperature, for this demo — that would be mounted in some remote location. The microcontroller needs to be powered, of course, and also needs to send a signal back to a central point to indicate whether the monitored location is within temperature specs. Both needs are accommodated by a single pair of wires and a tiny bit of additional circuitry. On one end of the twisted pair is a power supply and decoder circuit, which sends 9 volts up the line to power the PIC sensor. The decoder is based on a CD4538 dual monostable multivibrator, set up for an “on” time of one second. A trigger input is connected to the power side of the twisted pair going to the sensor, where a transistor connected to one of the PIC’s GPIO pins is set up to short the twisted pair together every half-second. Power to the PIC is maintained by a big electrolytic and a diode, to prevent back-feeding the controller. The steady 0.5-Hz stream of pulses from the sensor keeps resetting the timer on the control side. Once that stream stops, either through code or by an open or short condition on the twisted pair, the controller triggers an output to go high.

It’s a pretty clever system with very simple and flexible circuitry. [0033mer] says he’s used this over twisted-pair wires a couple of hundred feet long, which is pretty impressive. It’s limited to one bit of bandwidth, of course, but that might just be enough for the job. If it’s not, you might want to check out our primer on current-loop sensors, which are better suited for analog sensors but still share some of the fault-detection features.

Continue reading “Simple CMOS Circuit Allows Power And Data Over Twisted-Pair Wiring” →

LiPo Replacement Keeps Portable Scanner In The Action

November 21, 2023 by Dan Maloney 8 Comments

If there’s anything people hate more than being locked into a printer manufacturer’s replacement cartridges, it’s proprietary batteries. Cordless power tools are the obvious example in this space, but there are other devices that insist on crappy battery packs that are expensive to replace when they eventually die.

One such device is the Uniden Bearcat BC296D portable scanner that [Robert Guildig] found for a song at a thrift store, which he recently gave a custom LiPo battery upgrade. It came equipped with a nickel-cadmium battery pack, which even under the best of circumstances has a very limited battery life. Using regular AA batteries wasn’t an option, but luckily the space vacated by the OEM battery pack left a lot of room for mods. Those include a small module with BMS functions and a DC-DC converter, a 2,400 mAh 4.2 V LiPo pillow pack, and a new barrel connector for charging. With the BMS set for six volts and connected right to the old battery pack socket, the scanner can now run for seven hours on a one-hour charge. As a bonus, the LiPo pack should last a few times longer than the NiCd packs, and be pretty cheap to replace when it finally goes too. There’s a video after the hop with all the details.

If you’re looking at a similar battery replacement project, you might want to check out [Arya]’s guide to everything you need to know about lithium-ion circuitry.

Continue reading “LiPo Replacement Keeps Portable Scanner In The Action” →

Hackaday Links: November 19, 2023

November 19, 2023 by Dan Maloney 8 Comments

Two RUDs are better than one, right? That might be the line on Saturday morning’s briefly spectacular second attempt by SpaceX to launch their Starship vehicle atop a Super Heavy booster, which ended with the “rapid unscheduled disassembly” of both vehicles. The first attempt, back in April, had trouble from the get-go, including the rapid unscheduled partial disassembly of their Stage Zero launch pad, followed by rapid but completely predictable disassembly of a lot of camera gear and an unfortunate minivan thanks to flying chunks of concrete.

Engineering changes helped keep Stage Zero more or less intact this time, and the Super Heavy booster performed flawlessly — for about three minutes. It was at that point, right after the start of the new “hot staging” process, where Starship’s six engines light before the booster actually drops away, that the problems started. The booster made a rapid flip maneuver to get into the correct attitude for burn-back and landing before disappearing in a massive ball of flame.

Reports are that the flight termination system did the deed, but it’s not yet exactly clear why. Ditto the Starship, which was also snuffed by the FTS after continuing to fly for about another five minutes. Still in all, the SpaceX crew seem to be ecstatic about the results, which is understandable for a company with a “move fast, break things” culture. Nailed it.

Continue reading “Hackaday Links: November 19, 2023” →