I went looking for a remote-controlled power switch (the wireless christmas kind, not the modern IoT kind) and didn't find it, but I did find this thing I bought just to figure out why it exists.
It's a timer outlet, but you program it from your phone... but it's not wireless.

Yeah instead it plugs into your phone's HEADPHONE PORT
I got it on sale.
probably because iphone dropped the headphone port and they had to get with the 21st century and make it bluetooth
So inside the box is the device. it's got a little 2-prong polarized outlet with no ground.
on top is the only controls: on/off/timer.
then there's a 3.5mm jack here
turns out there's one more button! it's a reset button.
I guess the thing saves settings when turned off, because you have to unplug it to push the reset button.
Specs: up to 10 amps for a resistive load, and up to 5 amps for a tungsten load.
and this is just an aux cable
I hate when they're just like "download the app by searching for foobar".
That's putting some serious trust in your SEO, man
this is what the app is supposed to look like
thankfully it's still on the app store.
although it tries to sell me a bunch of unrelated movies first?
uh-oh, 2 stars?

one of my favorite things to do is to look up the ratings on IoT apps... they're never good.
apparently it requires a lot of permissions and barely works
huh, triangle screws.
whelp, guess I better get my dremel and paper clips!
so the app wants to take pictures, access your location,
make calls, and access all your files.
and if you deny it, it just dumps you in the settings page to fix permissions, with no message.
huh, not all of the screws are triangles.
there's 4 of them, and 2 are philips
I hoped that'd make more sense when I opened it up, like one went into a PCB and the other didn't, but NOPE! it's just because Reasons.
So here's the control board.
We've got a CPU and two smaller chips. Probably one is some kind of communication chip, and the other is a flash chip for storing settings?
Nothing on the other side but the LED.
Although this bit is interesting: L/R/+/-, on the cables going to the other board.
L isn't connected... I think that means there's a version of this that can control two outlets at once, not just one.
also HIDDEN BATTERY!
someday that will die and leak and the whole thing will be destroyed.
The other PCB.
I do like that they keep all the high-voltage AC stuff separate from the low-voltage DC stuff.
Cheaper versions of this would have just had one PCB.
That big box is a Massuse ME-11-I-012-1HS3AF relay.
So that's an inrush type relay, 12v coil voltage,1A contact form, sealed, 16amp rating, AgSnO₂ contacts, class-F insulation.
So back on the main PCB, let's look at that CPU.
It's a Sino Wealth SH79F166A.
which is an 8-bit microcontroller with 16 kilobytes of flash ROM, 256 bytes of RAM, and 1 kilobyte of eeprom-like storage.

AND IT'S AN 8051! EVERYONE TAKE A DRINK
Over here is a Holtek HT9274.
That's a quad-op-amp.
And this is a 026B-A-CF850S, which is an... air filter? hmm.
actually it turns out it's a battery charger/management chip, an XT2051.
because it has a battery, yeah.
so I was wrong, it does all the storage inside the chip itself! fancy.
so apparently the communication with the phone/tablet is two way!
because it can tell it's not connected properly, in this emulator I'm using
why does this look so iOS
it's an android app
thankfully they didn't obfuscate their java code, so I can see sound generation code.
it sounds like (NO PUN INTENDED) it has a protocol of simple tones that it plays at the device.
it also might not be two way:
android historically has had a AudioManager.isWiredHeadsetOn api which tells you if the 3.5mm jack is connected.
So it may just be detecting there's no headphones plugged in to my emulator.
sadly since it's gaming oriented it doesn't seem to have any way to shim that out.
so the Toner class has a bunch of methods that do various things, like playOn to turn it on, playRandom, playProgram, and playDusk (and "dust"? they seem to mix up dust and dusk a lot)
so to turn it on you send the simple command "1111".
and we can see over in getSimpleCommand that a simple command is a command + a clock sync + a length, then there's a checksum. And it logs all this for us! handy.
the clock sync stuff is the current date, daylights savings times, timezone, latitude, longitude, then CT and CD.
CT is "current time" as an integer of how many minutes it is into the day, and CD is the day of the week.
the day of the week is implemented in binary, with a fallback in case you're on an INVALID DAY.
(it's using Monday = 001, and counting up from there)
and here's the checksum function.
uhhh. I'm not sure I'm awake enough to figure this out, but... it starts by padding up to a multiple of 8 bits.
then it calculates a total sum by converting every group of 8 bits to an integer and adding them together
then it converts that to a binary number, and pads it out (on the left this time) to 8 bits
then it chops the checksum down to 8 bits... and checks if the last digit is a 1.
if it is, it adds a 1?
it's doing something like count up the bits, add that sum, but then add an extra 1 if it was odd. I think that means it's different lengths for even or odd? I may just have to stick this code in a harness and run it
yeah. it is variable length.
I don't know if that was intentional. I kinda don't think so.

More from foone

Everyone likes to forget this episode just because it's terrible, but we were really sleeping on inherent comedy in a unfreezing an investor 300 years in the future and having them discover we've transitioned to a moneyless post-scarcity utopia.


it's like a classic twilight zone episode.

in fact, it IS a twilight zone episode.
The Rip Van Winkle Caper, Season 2, episode 24.
Four criminals steal a million dollars of gold bars, then put themselves in suspended animation for a hundred years to hide from the law.

they wake up, then start killing each other from mistrust, then the last one dies in the desert, as he offers a gold bar to the driver of a passing car, asking for water and a ride into town

the confused driver walks back to his car with the bar, and his wife asks what the gold bar is.
he says something like "It's gold... they used to use this for money, before we figured out a way to manufacture it."
He tosses it away, and drives off.

More from Tech

A brief analysis and comparison of the CSS for Twitter's PWA vs Twitter's legacy desktop website. The difference is dramatic and I'll touch on some reasons why.

Legacy site *downloads* ~630 KB CSS per theme and writing direction.

6,769 rules
9,252 selectors
16.7k declarations
3,370 unique declarations
44 media queries
36 unique colors
50 unique background colors
46 unique font sizes
39 unique z-indices

https://t.co/qyl4Bt1i5x


PWA *incrementally generates* ~30 KB CSS that handles all themes and writing directions.

735 rules
740 selectors
757 declarations
730 unique declarations
0 media queries
11 unique colors
32 unique background colors
15 unique font sizes
7 unique z-indices

https://t.co/w7oNG5KUkJ


The legacy site's CSS is what happens when hundreds of people directly write CSS over many years. Specificity wars, redundancy, a house of cards that can't be fixed. The result is extremely inefficient and error-prone styling that punishes users and developers.

The PWA's CSS is generated on-demand by a JS framework that manages styles and outputs "atomic CSS". The framework can enforce strict constraints and perform optimisations, which is why the CSS is so much smaller and safer. Style conflicts and unbounded CSS growth are avoided.
A common misunderstanding about Agile and “Big Design Up Front”:

There’s nothing in the Agile Manifesto or Principles that states you should never have any idea what you’re trying to build.

You’re allowed to think about a desired outcome from the beginning.

It’s not Big Design Up Front if you do in-depth research to understand the user’s problem.

It’s not BDUF if you spend detailed time learning who needs this thing and why they need it.

It’s not BDUF if you help every team member know what success looks like.

Agile is about reducing risk.

It’s not Agile if you increase risk by starting your sprints with complete ignorance.

It’s not Agile if you don’t research.

Don’t make the mistake of shutting down critical understanding by labeling it Bg Design Up Front.

It would be a mistake to assume this research should only be done by designers and researchers.

Product management and developers also need to be out with the team, conducting the research.

Shared Understanding is the key objective


Big Design Up Front is a thing to avoid.

Defining all the functionality before coding is BDUF.

Drawing every screen and every pixel is BDUF.

Promising functionality (or delivery dates) to customers before development starts is BDUF.

These things shouldn’t happen in Agile.
The 12 most important pieces of information and concepts I wish I knew about equity, as a software engineer.

A thread.

1. Equity is something Big Tech and high-growth companies award to software engineers at all levels. The more senior you are, the bigger the ratio can be:


2. Vesting, cliffs, refreshers, and sign-on clawbacks.

If you get awarded equity, you'll want to understand vesting and cliffs. A 1-year cliff is pretty common in most places that award equity.

Read more in this blog post I wrote:
https://t.co/WxQ9pQh2mY


3. Stock options / ESOPs.

The most common form of equity compensation at early-stage startups that are high-growth.

And there are *so* many pitfalls you'll want to be aware of. You need to do your research on this: I can't do justice in a tweet.

https://t.co/cudLn3ngqi


4. RSUs (Restricted Stock Units)

A common form of equity compensation for publicly traded companies and Big Tech. One of the easier types of equity to understand: https://t.co/a5xU1H9IHP

5. Double-trigger RSUs. Typically RSUs for pre-IPO companies. I got these at Uber.


6. ESPP: a (typically) amazing employee perk at publicly traded companies. There's always risk, but this plan can typically offer good upsides.

7. Phantom shares. An interesting setup similar to RSUs... but you don't own stocks. Not frequent, but e.g. Adyen goes with this plan.

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