Notices by Bernie (codewiz@mstdn.io), page 6

Since it's my first attempt at SMD soldering, I watched a couple of video tutorials and then tried to solder the same component on this practice board.

The result doesn't look great, but it will suffice for this easy job: as long all 3 pins are connected to their pads and not shorted together, the CR2032 will deliver its +3V output to the RTC clock.

#electronics #retrocomputing

While my last retrobrighting experiment proceeds quietly at home (*), I went to the asylum to finish restoring the #Amiga 3000 battery-backed clock.

My kit requires a P-channel MOSFET. Instead of the recommended IRLML6401TRPBF, I found a similar part with higher current (fine) but higher drive voltage (2.5V):
https://www.digikey.com/en/products/detail/infineon-technologies/IRLML6402TRPBF/811437

To confirm it will work, I taped the mosfet to its tiny terminals and measured +3V on the output pins.

(*) https://mstdn.io/@codewiz/113710433519948326

#retrocomputing #electronics

@ellie who types echo 3000 times at an interactive shell prompt???

@SupportGrapheneOS_667 "The analysis of the DJI GO 4 app for Android revealed that the security issues are not there by mistake." 😰

While the #chemistry is the same, the conditions are quite different:

- I had to weight the plastic to keep it from floating: will the covered areas look different?

- The same UV light source is being diffused in a much larger environment

- 5W of light won't keep this larger reactor warm, so I moved my electric room heater next to it

- This cheap box doesn't have a gasket all around the lid. Will it quickly vent out the radicals produced by peroxide decomposition in UV?

#retrobrighting

I also bought a Sterilite storage box large enough for the A3000 keyboard. I believe it's made of polypropylene or polyethylene, which shouldn't block UV too much, but since my led strip is IP65, I figured I can just hang them on the inside of the lid.

While waiting for one gallon of 12% hydrogen peroxide from Home Depot, I started another #retrobrighting experiment with concentrated sodium carbonate solution, just on a larger scale than the minus key.

#chemistry

Upon connecting to my old Mini 2, the app wants to install a 60MB firmware update. Ugh.

Then comes a "FlySafe Database" update. Hmm, ok.

After a couple of reboots, we're finally ready to fly. But now it's night, so we'll have to wait until tomorrow 😄

Anyway, the app works and requested access to location and media files, both of which seem plausible for a camera drone.

A more modern Android SDK would have allowed narrower access to videos, but anyway...

Since I can't verify the stories against #DJI, I cautiously decided to keep their apps off my Pixel phone for now.

Instead, I'll put it on my #LineageOS hacking phone, an old but trusty OnePlus 7T, which shows the same scary message, but this time I take the time to read the small print:

"This app was built for an older version of Android and doesn't include the latest privacy protections."

So, was that a simple API level deprecation issue that DJI could have fixed by upgrading the SDK?

I worked on #AOSP for 3 years. It's enough to know that there are millions of devices in the wild running ancient kernels with unpatched security holes.

Android system permissions add a second line of defense, but stores also use a combination of security reviews, developer reputation, user reports and static analysis tools to catch malicious apps and actively kick them out.

Just a bug then... seems plausible.

But the #DJI apps have been unavailable from the Play Store since early 2021. Which SDK bug couldn't be fixed in almost 4 years?

On the other hand, if Google had genuine security concerns with DJI's apps, why would Apple allow them?

But there are also less conspiratory explanations:

It's in the apple app store. [...] And while the spyware angle is 'fun,' it's a pretty goofy logical jump. The real reason appears to be a compatibility issue, "Google announced a while back that app developers will have to ensure their apps are packaged as bundles (AAB) rather than the standard APK. According to a DroneDJ reader, DJI’s SDK has a bug that prevents it from compiling in this new AAB standard."

https://www.reddit.com/r/dji/comments/144x6c9/comment/kqj75cb/
#DJI

The absence of official statements from #DJI and Google is suspicious, and news outlets support the trade-war theory:

barrons.com: "DJI was previously blacklisted by the US Department of the Treasury in 2021 for allegedly supporting the surveillance of the Uyghur minority in China's Xinjiang region."

wsvn.com: US customs officials have also blocked some DJI shipments over concerns that the products might have been made with forced labor. DJI has called it “a customs-related misunderstanding.”

I have an old #DJI drone from 2020, and noticed that the DJI apps are gone from the Google Play Store.

I can go to https://dji.com and download a whopping 861MB APK, but my Pixel Phone puts up scary security warnings that I've never seen with other APKs from F-Droid.

So now I'm not sure whether there's an actual security issue with DJI apps or it's just some US-China trade war bullshit.

@jamie The 8-bit guy made exactly the same joke a few years ago: for some reason, he couldn't use the Ctrl key as a control in his experiment comparing various #retrobrighting methods.

And I also couldn't, because both my Ctrl keys are visibly less yellowed than adjacent keys.

I've seen keyboards whose space bar is more yellowed than the rest, but that's the only key having no engraving so it's plausible that it went through a different process.

So, why Ctrl?? 🤷

#retrocomputing

@nop Dipped the key in a highly concentrated solution of sodium carbonate in a sealed plastic box for food, wrapped with a strip of UV leds (5 watts), and further wrapped with a towel to keep the box slightly warm. Cook for 12 hours.

The plastic is slightly opaque, probably polypropylene or polyethylene. I don't know how to tell how well it transmits UV light at 390-400nm. I've read that common glass blocks UV more than most plastics.

@dnc All right, which vegan cheeses are actually good? I keep buying different brands and styles, but none of them comes close to the real thing.

Crave for good cheese is the main issue preventing me from upgrading from #vegetarian to #vegan.

@dan I've already tested that sodium carbonate to rewash some yellowed kitchen and bathroom towels, but they still look the same.

Guess I'll ask for a refund 😉

@jxself And where would I get these test strips from?

As you just saw, I'm totally clueless and confusing "sodium peroxide" with "sodium percarbonate".

Ideally I'd just get a can of Mom's Old-Fashioned Retrobrighting Lotion (made with 10% more love than the next leading brand!)

Before realizing that sodium percarbonate was actually what I was supposed to use, I started a small AB-test in my UV chamber using plenty of sodium carbonate.

After spending about 12 hours dipped in the solution, the '+' key (treatment) is visibly less yellow than the '-' key (control).

Despite using the wrong #chemistry, my first #retrobrighting experiment didn't completely fail. Can anyone explain this surprising result?

#retrocomputing #vintagecomputing