Avatar
ElectronicsQuestions
a2a48499c402432a36b5384148372c647cbd68d0bece80b2d010756c3c5df349
Ask me questions about electronics on the circuit level. I don't know about Raspberry Pi:s, programming modern microcontrollers etc, but I do know about resistors, capacitors, inductors, voltage regulators, op-amps, digital logic, and so on and so forth. I can probably help you repair something or build something. I also know a thing or two about mechanics. If my service is free or paid is up to you! Nostr and Lightning is new to me, I'm trying to learn, so please excuse any errors on my part regarding it. I live in Sweden.

Indeed. And the prime culprit, at least what I believe, flicker, is back with the PWM control of LED:s. We had a while with cold cathode fluorescent tubes as backlights, which had less flicker, but now with LED:s, it's back at 100% modulation, except in a few monitors which control the current instead. I don't know what technology these goggles use (LED backlit LCD, OLED, etc.), but it's pretty likely that they too flicker.

Depends on if the picture is from a country where they drive on the left or right side.

I have had this anger, not least regarding privacy, for at least 16 years (FRA law, Swedish surveillance law, in 2008 IIRC). It has largely turned into sadness and partially to self-criticism/wondering if I'm the problem, since very few seem to be on my "frequency" in these thoughts. (Extremely few seem to think that the growing panopticon is as dangerous as I think it is, or attempt to do anything whatsoever to put brakes on the way things are going. Many, like what you're talking about, want it. "against the gang violence" etc.)

My childhood didn't help, as any anger on my part was never explored and usually discouraged to punished to varying degrees by my mother. Sorry if TMI, just want you to know where I'm coming from.

(I strongly doubt all this is healthy for me in the long run.)

I definitely see the benefits of these technologies, and I'm fully with you that they are needed, but I'm still worried about the future of free communication. I don't know if I'm missing some point, since everyone seems so convinced about these things, I hope you or someone else can clarify on the technical details:

1: ChatControl. This is on the table in the EU, may be approved in October if I understand it correctly, and means that either chat apps/services or operating systems, maybe both, are required to have client-side scanning. Will it be possible for a non-programmer to download software (OS) and use a web client/download a client (depending on circumstances and which of the technologies it's about), that's not compromised, and will it be possible to have a reasonable certainty that such is the case? Can't be sure unless you can check the code of course, but reasonably.

2: ISP:s. What prevents government from mandating ISP:s to block all encrypted traffic, unless it for example is going to whitelisted servers, or is signed by approved apps?

3: Extreme measures. Using a printing press was once punishable by death. Printing presses are physical objects without an online footprint, and this was in an era way before cameras and microphones existed, and today they are, obviously, legal. However, what prevents government from using a crisis and the media to condition people, and let ISP:s or other internet system actors, or intelligence agencies, look for traces of these tools being used, maybe even holding each subscriber accountable for what happens on their connection regardless who uses it, and put a few users of these technologies in prison for a long time, and use the mainstream media to make examples out of them?

Don't get me wrong: a world with these tools you mention is better than a world without them. What I wonder is whether it will be enough. If this battle is lost, these freedoms may very well be lost forever. Yet "bitcoiners" (TM) act like success is 100% certain. If I'm not wrong on all these points and more, and I hope I am, that stance is either dishonest or uninformed, and I dislike people of the former, and want the latter to learn. After all, the same people say that "bitcoin is truth".

The problem with this reasoning is that it only works in large numbers, particularly it doesn't work as long as the police, the tax agency workers, etc, aren't among those whose attention is lost.

A single person would end up with their fiat assets frozen/confiscated and/or in prison.

A properly designed device can't cause a battery fire with software alone, it would have to be hardware modified. Any EE worth their salt would know to incorporate a physical protection circuit, such as a DW01 with the two accompanying MOSFETs, into any li-ion cell powered device that can have a failure mode that overloads the battery.

Not saying that every EE is worth their salt though, especially regarding things bought online in places like Ebay, Temu, etc.

The Swedish page has nothing to do with this. It's about a Gothenburg politician losing his position because he supports some terrorist classed Palestinian group.

HUNGARY PROPOSED MESSENGER PROVIDERS FOR TIGHT SURVEILLANCE

Following the pressure of privacy & human rights activists the Hungarian Presidency claimed to do "a compromise". In practice the upcoming #ChatControl regulation will require from messenger providers "to do their utmost to contribute to the development of reliable and accurate technologies to detect new CSAM and grooming."

It means more tight surveillance, including indiscriminate mass monitoring of private communications and the end of secure end-to-end encryption. https://emanuelkarlsten.se/wp-content/uploads/2024/09/240829-CRPII-4-september-st12319.en24.pdf

In response to this proposal, over 245 scientists from 31 countries evaluated #ChatControl draft as ‘ineffective, false positives, defeats end-to-end encryption, disproportionate, violates right to privacy, new vulnerabilities’. https://homes.esat.kuleuven.be/~preneel/Open_letter_CSAR_aug24_still_unacceptable.pdf

1️⃣ What you can do now:

🔻Call your goverment and deputies to reject alltogether Chat Control. Find contacts here: https://op.europa.eu/en/web/who-is-who/organization/-/organization/COREPER/

🔻Support politicians like @echo_pbreyer who promote privacy!

🔻Explain why it won’t help in bringing security for our society. Opposite, such approach would put the future of our freedoms is just one step closer to be compromised and abused by dictators.

🔻Address your government before the next meeting on 2nd Oct.:

🔴SUPPORT Chat Control: Bulgaria, Croatia, Cyprus, Denmark, Finland, Hungary, Ireland, Greece, Latvia, Lithuania, Malta, Romania, Slovakia, Spain, Sweden

🟢AGAINST Chat Control: Austria, Belgium, Czech Republic, Estonia, Germany, Luxembourg, Poland, Slovenia

🟡 UNDECIDED (we need to activate them the most!): Italy, Netherlands, Portugal

🎙Respost and call you friends to join the campaign today: If no privacy of communication, no protection for children, anyone in the EU and beyond!

2️⃣Rember and explain:

🔻No algorithm can reliably make a legal assessment. According to Meta, which is the source of the vast majority of reports, they currently only look for known CSAM in EU communications, and yet at least 50% NCMEC of reports made to German law enforcement agencies are not criminally relevant, according to the federal crime agency (BKA).

🔻EU Commissioner #Johansson admitted in late 2023 that 75% of NCMEC reports are not of a quality that the police can work with.

3️⃣ Dictators love Western spy technology: the example of the Intellexa spy company proved: dictators all over the world love Western spy technology for transnational repression of opponents and destruction of the Western world, your and your family freedoms. Urge your government to stop this! https://www.woz.ch/2439/predator-files/die-schweiz-als-drehscheibe/!NN0B9QYP1H7V

This has to be coming from above somehow, some organization that somehow blackmails the politicians and perhaps even the media directly. So many, including the people with fancy titles that you mention, who have already contacted the politicians and they are still at it.

I live in Sweden, and I think the Swedish mainstream media have mentioned it once - a short general overview with focus that it's "against child abuse material". No discussion of the implications on privacy, cybersecurity, risk of slippery slope, anything like that. I don't consume a huge amount of mainstream media, sure, but a reasonable coverage of this would be at about the same level as that of the wars in Ukraine and the Middle East. Which is pretty much daily news on at least one of the two.

You can legally listen without a license in most places (IIRC, not in UK). An RTL SDR is a cheap device that can receive a lot of radio transmissions, including HAM bands.

No license or anything like that, but I have an RTL SDR that I listen to HAM bands with sometimes.

Replying to Avatar Lyn Alden

The electronic project that I am most proud of from my engineering days, was also the most useless thing I ever built. I was reminded of it amid all the censorship in Brazil, because it’s about Embraer avionics, which are Brazilian.

A short story.

The background context was that I never considered myself to be a great engineer. I was more interested in finance but had gone into engineering instead, and basically what makes someone great in a field is whether they have the passion to do it in their spare time or not. The best engineers, after school or after work, go home and do more hobbyist engineering stuff. Like, they just live in it. I spent my spare time on financial research instead. I liked my engineering work, but was only a design engineer when I had to be, basically. My passion was elsewhere. So I knew I'd likely eventually go into engineering finance/management in that kind of hybrid role.

I went to work in an aviation simulation facility after college. Rather than being used for training new pilots as most airplane simulators are, this facility was used by corporate, academic, and government researchers to test new technologies and procedures with experienced pilots. So the simulators were more customizable than training simulators, but were less polished. They were always these cool work-in-progress machines.

We had Airbus, Boeing, and Cessna models in the early days. And we had a half-finished Embraer, simply because the manager of the simulation facility just wanted an Embraer due how cool and different they are. His higher-ups in the broader parent organization told him there wasn’t enough market demand for testing in Embraers and wouldn’t give him a budget for it, but he kept finding ways to gradually accumulate the parts anyway. Eventually he had the simulator shell, and genuine avionics, but still had to put it all together. The Embraer avionics and flight controls were just so much more interesting and sleek than the other types.

In our Boeing and Airbus simulators, we had genuine avionics, but interfaced them into industrial automation control logic and PCs, rather than what they normally connect to in the field. And it wasn’t hard because they used some standard communication protocols like RS-422 or RS-485. All the buttons and dials were easy to connect to automation control systems, and the serial communications were things you could buy a PC card for.

But the Embraer sat unfinished for years partially because there was no budget for it, and partially because it didn’t use those standard serial protocols. The serial communications coming from their flight panel and throttle were some custom method that none of our equipment could read. You could just rip it open and re-do the insides to talk to a PC more easily, but the manager forbade that; he wanted the Embraer avionics to remain pristine. We had incomplete documentation, and virtually no budget or labor to put into it beyond the pieces we already had. It was this hacky project. We didn’t even really have electronic design software other than a lapsed PSpice license, since we rarely did any sort of custom circuits and instead would interface various devices into automation systems.

So, getting the Embraer up and running was always on the manager’s pet project to-do list but not making much progress. He would occasionally put an entry level or intermediate level engineer on it for a few months and they’d eventually give up, leave the organization, or go back to something more economically relevant. It went on like that for years; it became the Kobayashi Maru for electronic engineers in this facility.

After my first couple years working there on the Boeing, Airbus, and Cessna, the manager was eventually like, “alright, I want you to see if you can get that Embraer flight panel connected.” Little budget, just me in the lab with an oscillator and multimeter. I knew this would happen one day- the Embraer avionics were always kind of looming in the lab, next to half-finished failed creations of my predecessors that tried to interface with it, knowing that eventually I’d be put to work on this thing. And I still had other duties to do, so this was like a budget-less side project I had to spend part of each week on, with insufficient equipment and documentation and with the knowledge that the Embraer simulator might not even be used if I somehow succeeded.

So I dove into it. The Embraer flight panel had a series of buttons, but unlike our other flight panels, they all went through a parallel-in serial-out (PISO) shift register. So they came out of the device in a fast custom serial communication stream. An external device had to give the flight panel a clock signal, and give another CLR signal that would be low for 24 milliseconds and high for 1 millisecond, and during that 1 millisecond there would be 256 clock signals, and the flight panel would output all of its current states of button and knobs within those 256 clock signals within the millisecond, every 25 milliseconds. And the CLR signal had to be shifted some microseconds away from the clock signal so that the signal edges of their square waves don’t occur simultaneously, which would cause reliability issues. The incomplete documentation we had only roughly outlined this; I had to iterate a bunch of oscillator tests to see what successfully worked as an input, and then more fully document where every button and dial showed up on the output data stream once I got it flowing.

And then once I figured out how it worked, I had to figure out how to connect it to a PC and/or our standard industrial automation interface.

At first I tried one of our 2 year old microcontrollers that we had on hand, which as of this writing are now nearly 15 years old so not the current generation stuff. I looked to see if I could program it to send in these signals and then read the signals coming from it, but it wasn’t nearly fast and precise enough. This project needed lower-level design than something software-based.

I wasn’t sure if FPGAs of the day would be fast enough, I hadn't worked on them before, and and we didn’t have any anyway. So I went the raw logic route instead which would be annoying but cheap and guaranteed to work. I researched crystal oscillators, logic gates, counters, flip-flops, and serial-in parallel-out (SIPO) shift registers. I then used them to build this whole digital clockwork circuit from scratch to basically reverse everything that the flight panel was doing. It would use a crystal oscillator as the initial frequency, and from that would generate the clock signal and the CLR signal to send to the flight panel, and would run the timing for a bunch of SIPO shift registers so that this stream of serial data coming out of the flight panel would load into the shift registers, then get frozen in place for 24 milliseconds which was fast enough for our slower industrial automation interface to read the data which was now in parallel form.

Then I bought all the cheap logic pieces, soldered together test circuits, troubleshooted it, and got the thing working. I came in alone on the weekends to do it since I had little time in the week; I was just caught in the flow of making this work. Rather than viewing it as annoying as I did early on, I now viewed it as something I had to beat.

And then the Embraer throttles were the second difficult piece. Rather than a normal position output as our other simulator throttles did, the Embraer throttles basically outputted sign waves, and as you moved the throttle, which was really well-crafted and smooth, the two sign waves would overlap to varying degrees. So I had to map that all out, build a circuit to read these sign waves and send that position data to the slower industrial automation interface in a way that it could read it. I then soldered together the circuits, and got that working too.

I then wired up all the more standard electronics in the Embraer which were not that different than the other simulators. And so, I was finally able to go the manager and say, “the Embraer’s flight controls and avionics are all connected now! ^_^”.

I remember being so proud, like, “oh shit, maybe I could actually be decent at this.” And the custom circuit interfaces indeed worked for the next decade and counting without maintenance, perfectly reliable. We then got the rest of the simulator fully set up.

But… the Embraer simulator was only used like one time, barely. No research teams wanted to test new technologies and procedures on Embraers; they would always test things on the Airbus and Boeing simulators. So this awesome simulator, with so much work poured into it, was a complete waste of time, which is what the managers’ higher-ups had told him from the beginning.

I went on to do a bunch of other projects including a business jet simulator and a helicopter simulator and an upgraded redesign of our Cessna before I went into management and out of design engineering, but nothing was quite as hacky as that Embraer simulator, so it was always the one I would look at fondly and be like, “I can’t believe this useless thing is still running.”

Rather than feeling sad that the work was wasted, I instead always kind of had a “journey before destination” mindset to it, like it was the most frustrating project that I had brute-force succeeded at, from research to design to physically putting it all together to troubleshooting, and gave me a bigger sense of achievement and got me into a higher state of flow than other engineering projects I had done. To this day, I always think of Embraer planes warmly.

Were the throttles sensed by [resolvers](https://en.wikipedia.org/wiki/Resolver_(electrical))? Two waves, their amplitudes* corresponding to mathematical sine and cosine of the mechanical position.

*Positive and negative, shifting "polarity" (or phase 180 degrees) when passing the zero point.

Haven't been on here for a while, sorry for late reply.

Maybe. But how about removing those systems and letting people keep their money regardless, so that those who want four kids can afford it, reducing their stress over money and giving them time to take care of them, while removing all pressure on those who want fewer or none (especially for the reason of knowing their own limitations) to have more for economic reasons? #LibertarianDreaming...

I'd say it'd increase the amount of bad parenting if the incentive to have more (or any) children is for economical reasons, and not that you want to out of love for them. Even partially I think it would be true.

I doubt a CBDC would be necessary here. You know how the Swedish system works. The ones in power, whether official power or (usually) not, hints at something being necessary and the right thing to do, and the media immediately takes their side, and every company bends over backwards in a competition of unnecessarily exaggerated compliance, putting up signs bragging about it.

Add a nearly cashless society, where almost everyone has digital ID in the form of Bank-ID (and you are generally looked at as the sole cause of your problems if you don't want to conform to this), and it wouldn't be any problem whatsoever to introduce limits and blocks on who can buy how much of what, if they decided to. Most people (especially in the big cities) would probably think it's great too, at least if it's portrayed as being for the climate.

If it wasn't for the fact that most TV and radio speakers can't reproduce such frequencies, they could possibly have been using [https://en.wikipedia.org/wiki/Infrasound#Human_reactions](infrasound) for a real-life counterpart. Sometimes it's good that technology isn't perfect...

All the ones I listed are browser based - should work on a Mac too. Addresses:

satellite.earth

iris.to

coracle.social

It seems to depend on the client too. This was a while ago, so it may have been fixed, but I noticed that two different clients, despite having the same relay list, was different in what they showed - one of them only showed some of the notes of the people I followed, while the other showed, as far as I know, all of them. I think it was Coracle that didn't show all, and Iris that did, but I'm not 100% certain. Currently I'm using Satellite, as Iris became worse over time and eventually stopped working in my browser. I haven't tried it for a few months.