It is funny people can't envision things breaking...
(And before you ask, the light was in a corridor but there was no door to the bedroom. The switch was stuck on because it was broken not because it overlooked the bed -- it did not)
This is what enraged me about the Therac-25 design which ended up killing people. There's a whole report to read on the design, failure and follow up but to paraphrase the designers eliminated the physical locking mechanism and had this attitude that "oh it's electronic so it won't wear out and fail".
Software errors killing people with excessive radiation doses.
It’s related to why memes exist.
If you want recent one, 737 MAX, killed way more than Therac-25. Although it was as much fault of software as suits around it wanting to save a penny on training, because if pilots knew about how it exactly worked they could've circumvented it
To the credit of systems engineers, I can't think of a recent high profile fatal accident that could be reasonably blamed primarily on software, but that's not so much because software is infallible, but because systems are designed to fail safe.
I’m sure I read that
There was a bug that caused the AOA DISAGREE alert on the EICAS not to be displayed, because at some point someone misunderstood the requirement that the AOA indicator should be hidden if they didn't pay for the upgrade, but this was just an indication and wouldn't have affected control at all (though likely would have hinted the pilots to a more appropriate cause of action).
One could also consider the lack of cross-checking between the two flight computers and associated AOA sensors to be a bug, but that was how the system was intentionally designed, because AOA wasn't considered a flight-critical measurement in the system's safety assessment, so they didn't consider this required. A holistic safety analysis was never really done inclusive of MCAS though, and this requirement probably just followed on from 737NG and wasn't really considered (at least thoughtfully...) in MCAS' design.
* each flight computer used its own angle of attack sensor with no way to detect failure. Craft had 2 sensors, but they were not used together (apparently that was extra paid option...) * pilots didn't know how the system worked or when it is active, so they were fighting against it
don't remember anything about overflow
Or perhaps this failure settle the argument about whether or not physical lockouts were necessary and due to regulations you can no longer rely solely on software?
And it would have been entirely fine if there was electronic safeguards put between code and rest of the device, just like some stop lights have it (if control board sends green signal to both directions it fails out and doesn't allow that). Defense in depth and all that
https://engineered.network/causality/episode-39-therac-25/
Each episode focuses on a root cause analysis of a major engineering disaster. Presented in a dry but engaging way - he's a good presenter, but none of the "Radio Lab" style nonsense.
From the lights turning off? A ten year old?
What I gain from this is trying to move us away from comments that serve no purpose other than copy-editing each other and discouraging people from posting unless they can be confident in their adherence to the unwritten HN style guides. Which many people never can be, for various reasons.
If they had said that as part of a comment that overall served a different purpose I wouldn't have said anything. But it added nothing to this discussion except reinforcing the atmosphere that comments must be finely tuned to be taken seriously.
>FWIW I do have that condition as well, though it isn't usually called that these days
I know, never cared much for the politically and financially motivated rename, that imho blurs the condition across a larger area, instead of defining it better.
In this case since the guy it was named after would have killed me given the choice, I'm glad they renamed it. Good info about where you stand though, thank you.
You appear to stand in a worse place, implying people are Nazis because they're OK with using the traditional name for a condition, just because the person who did studied it had connections to them.
Your quick judgement of others, is worse than that - more Nazi-like in practical action, than some "association by name used for a condition" (which is no associatation at all). If I got power I'd be OK with some tainted names.
If you got power you'd classify people as enemies, or worse, based on such trivial matters as whether they prefer the older established name for a condition (and don't particularly care if we don't retroactively erase the person who discovered it from medical history for his crimes 80 years after the fact).
I don't think I've ever been in a "pitch black" hotel room. I'd bet there was light enough for him to start seeing just fine after five minutes.
The ghost stories, sure. But then he's scarred for life more by the ghost stories rather than by the lights turning off...
Pretty sure that was just being used as an example to underscore a broader point. No need to nitpick.
edit: and now I'm 100% sure there are bots downvoting my comments, immediately downvoted less than minute from posting
not sure what should go wrong when you switch on the power again, blackouts happen
Also... you know... there are these funny little devices called switches that allow you to turn individual devices on and off without cutting power to entire apartment. Just saying...
My first reaction would have been what OP suggested.
And even the current code in CA doesn't require separate circuits for each room. They require separate circuits for different functionality. E.g. lights vs power plugs.
Then Big Lighting ruined that by going to LED strips and what not.
Some might, but I doubt they are a lot. None have such where I am for sure. People would need to turn power off for specific rooms/circuits or the whole thing once a year or so anyway (to do some electrical work, to change some light fixtures, etc). It also happens by itself if some machine overloads/there's a sudden surge. I've changed several rented houses, and it would ocassionally happen to all of them.
As for the fridge, he did say to leave the kitchen (or fridge including) circuit on.
Just your subjective knowledge of your local area and class of home you normally experience.
Not everybody enjoys the security that western democracies provide (although US and couple other countries seem to be slipping behind). In most of the world people with wealth above standard have to actually take special, pretty expensive precautions to preserve their wealth (and in some places lives).
Here people install security to call security company whenever the alarm is tripped. Lack of power is immediately suspect (thieves like to cut power). The security company is notified by the automation and they call the owner for security code. If the owner does not give the security code within required time they will immediately dispatch their patrol. The owner also has special security code in case he is compelled to give one and this triggers a specially escalated response.
So, like yours? When you said "A lot of apartments here have security devices" did you qualify it as "in non western countries with the right balance of affording security services and intenterrupted mains power"?
>Not everybody enjoys the security that western democracies provide
Well, not everybody who doesn't enjoy "the security that western democracies provide" has money to pay for a security company - or even the luxury of continuous power that is not frequently cut anyway, either.
In the context though, in a house with automatic sensors and such, I'd consider my case more likely.
I documented a bit recently as in France we will potentially have 2h power extinction at grid level during this winter. Apparently you can have your fridge safely keeping your food for up to 4h, but you should not open it during that period obviously — although since I don’t have any radiator in my kitchen I’m rather confident it wouldn’t be that problematic in the middle of a winter that is announced especially cold.
Kinda depends on fridge, altho sadly it's rare to see that number in manuals.
But one trick is to just take food that you want to eat anyway from the freezer and put it in fridge, the food will slowy defrost while cooling the fridge food. Just make sure water have somewhere to go
that's quite rare and bad design if you can't go overnight without power
>Then there are devices that expect power 24/7 like fridge.
that's why i said to leave kitchen ON, not that Airbnb fridge on first night would contain anything requiring power anyway
> Also, since I was abroad, I relied on the Internet that was at the apartment that would be cut off if the power was turned off.
dunno about you, but when I sleep I don't use internet, but maybe you are able to disable some parts of brain and use internet while sleeping
>Also... you know... there are these funny little devices called switches that allow you to turn individual devices on and off without cutting power to entire apartment. Just saying...
Also you know maybe read the comment I'm replying to about faulty automatic switches impossible to switch off.
I thought HN readers pay more attention to what they answer to and the context, but after reading some replies to my comment I've lost all hope that this site is any better than Reddit.
And maybe all those people reading HN and clicking into the comments of this post are actually bots.
obviously other more elegant solution would be unscrewing bulbs, but they may be not accessible
That's a bit of a weird claim. I'd say it's likely to be at its most full on the first night.
Is the first thing you do in the afternoon after checking in airbnb place going to shop to buy tons of supplies to store them in fridge?
I'd think people have better things to do on the first evening than shopping for groceries besides something small for dinner (if any) and those few dinner things would be fine even without fridge or not worth sleepless night with lights on.
Did you consider the insulin fridge in the garage you just shut off when you did that? How about the attic fan that keeps the place cool? The water softener that needed to do a recharge cycle. The electric vehicle plugged in that was waiting for night time trough to charge. etc, etc
> edit: and now I'm 100% sure there are bots downvoting my comments, immediately downvoted less than minute from posting
No, you’re just inconsiderate of people’s property.
you come out as completely ignorant of context who just gets angry for no reason
> you come out as completely ignorant of context
Says the commenter who didn’t follow the context.
By comparison the Clap switch is so simple that if it is quite at least you can sleep at night
Ah, the ideal of progressive enhancements. We know how that ended for HTML and JavaScript.
I agree with you but long term I believe that's going to be a losing game (except basic safety access akin to fire stairs today).
But this is directly against the easiest line of profit so no, vendors will not stop going in that direction even if it makes no sense to most people.
Which is why online enabled devices are popular and why companies cater for them.
If they could sell large numbers of offline versions at a markup, they would.
"Here is a box, we just run a container on it with your stuff, you can configure it in cloud as usual but all the stuff is run locally. Pay us monthly for convenience of setting it from cloud and software updates but don't worry, if we get out of business It Will Still Just Work".
I solved opening the garage door when leaving by a much simpler approach: “Alexa, I’m leaving”(regex for various phrases) along with an Aqara button if I was on the phone.
For arrival of my car only, and not triggering when I would walk nearby (park and beach 1 block in either direction), I had home assistant dialed in to notice the Bluetooth connection to my cars audio by its ID from within the app etc. along with the proximity and whether I was moving towards or away. Away would close and towards would of course open. This was particularly tricky but as you explain always failsafes in place: garage door opener in car and for the opening mechanism was set to close in 2 mins but reset if there was motion in the garage. If I was marked away and there was motion in the garage it would close and also sound an audible alarm.
None of those of course would have been possible without NodeRed. It’s so much fun to use.
NodeRed is great. I don't use it but if you don't want to spend a ton of time writing rote automation in code it's a dope option (and that's an absolutely fair take to have imo).
I call this the grandma test. Can grandma come over to my place and still operate everything she needs without a CompSci degree.
It is definitely possible to have a very smart home but still have physical fallbacks that cater for most visitors.
Turns out "Mmmmffmghfff!" is not a valid Alexa command.
Also a bad idea to have a voice activated door during torrential rain. (Which is a silly example. But even so.)
It's not even a UI problem. No one is going to be happy if the power goes off and they can't get in or out.
Or the lock fails open and everyone can get in and out.
Though not always cheap to operate, depending on your electricity costs.
I agree that liquidated equipment is great for these purposes (both servers, thin clients and small form factor office computers), but do a rough estimation of not just purchase cost but also yearly electricity cost. Some stuff is great, some stuff is being liquidated because of uneconomical TCO compared to newer equipment.
Few modern ones (on Intel side, AMD seems to be terrible with idle power usage) are not too bad but get something old and you'd be seeing 100W+ constant usage
They work beautifully with Hue bulbs and HomeKit, as well as offline without WiFi. It also avoids the situation of people disabling smart bulbs by using the physical switch.
my new house has all zigbee enabled stuff. I had zero say in it. I will use them for awhile. But I know eventually I am going to get extremely angry at them and will just go buy a pile of eaton and ge light toggle switches and basically not worry about it again. Also someone in this thread suggested a separate network. Good idea. Guess I am going to be buying a decent router at some point.
Surely you aren't also expecting to use the same lightbulbs for 70 years? Of course most of the Zigbee stuff won't last 70 years, but it isn't fundamentally all that different from light bulbs and other household appliances not tending to be able to handle regular use for 70 years. Especially lately with most 'smart' light bulbs being in the same form factor as 'dumb' ones.
As for switches, it's a digital system, if the switch breaks you are carrying a device capable of fulfilling the same function in your pocket (and potentially even wearing such a device on your wrist).
If the service/app is still around. And your IoT system? Is it compatible with the latest ver of android or iPhone? Many of these companies come and go very quickly. Pretty much as soon as the VC funding runs out, or they want to go play with 'their newest stack'. Then you get to spend another 200 bucks for a new 'hub' so the app can work again. Then hope the new hub can interpolate with the old gear. Else you get to update that too.
Home IoT gets one thing very wrong and it is why many do not want it. Timeframes are measured in 1-3 years instead of 1-3 decades. I know what timeframes I expect different parts of my system to work in. Short timeframes for toggle switches feels wrong. Because I can spend 3 bucks and have a switch that lasts decades with nearly zero upkeep and little to no ongoing monetary cost.
Also support is kind of random. Take for example Linus tech tips. He went full on into home automation. Yet even being a decent name in tech, the company that sold him his switches could not give him the right thing. He has a good chunk of his switches that may or may not do what he needs. Firmware update would fix it. But to do that he has to buy random update stations that may or may not come with the firmware. That is 1 toggle switch with a motion sensor. Stack all of that together and you get random 'well this bit does not work right'. I really do not want random when I walk into a room if the light will turn on and stay on. Then do what it says on the tin and turn off when I leave. If Linus can not get these companies to do the right thing what hope do I have?
Home automation for me is in that uncanny valley of frustration and magical. I used to write industrial ones. My timeframe of 'it has to work for a long time' is very jaded by that.
I can see you and I are optimizing for different results. I am optimizing for 'do not have to mess with it again or as little as possible' and you are optimizing for 'check out what my house does'. Both are worthy goals.
My 'service/app' is an open source program (Home Assistant and Zigbee2MQTT, although previously I have used NodeRed instead to provide the browser based control panel), the hub is an old server with a usb dongle with open source firmware. While there is an app available, there doesn't have to be one as there is also a browser based interface (which doesn't have to be exposed to the internet). The bulbs are a mix of various cheap brands off Amazon which are popular enough to have good support.
Sure, I have the benefit that as a techy I can handle (and to an extent enjoy) maintaining this, but that's mostly a matter of proper packaging, as it isn't a particularly complex thing to set up and is pretty close to zero maintenance.
Just have everything talk (via MQTT or whatever) to local hub (that could double down as internet router, or whatever else) running a container with queue server.
Then you can just spin up second "app" (another container) with local controller, or connect that queue to vendor's cloud and their own app. Or have failover between one and other. Hell, integrate the two where you have one place to add all of your rules, but what is possible to do locally would be done.
The vendor could charge monthly for their cloud toys but not have to run all automation in the cloud (cost savings) and the user would get a box that can be configured from anywhere, but do vast majority of tasks locally and not be dependent on internet for basics.
That said, I built up an ideology that any automation added should never replace physical items. All automation should have physical kill switches. Any occupants of the home should have appropriate access to things that you would normally give them physical access to.
I implemented walking lights successfully in my old house by replacing switches and doing some neat presence detection (near-field and general) tricks. That mode could be turned off at the front of the house, and frankly I found myself using it because it'd get old sometimes, and other times you really do want all the lights on.
My garage door opener was another. With near 100% accuracy my garage door would open when I was coming down my alley way. It never false opened though, even if I stopped at the grocery store in front of my house. It sometimes failed to open and I actually had to push a button in my car.
Another note, not mentioned here from my skimming, is to never rely on cloud devices. Anything worth doing is worth doing off-line. If your home automation and security can be killed by chopping fiber or coax, then you have neither reliable automation or security. There's infinite options for off-line applications and liquidated DC servers are stupidly cheap to purchase.
Last, if you're going to do home automation, make sure you start by building it on a separate network from your browsing network (preferably air gapped) - especially if you intend on using WiFi devices. They will crowd and slow down your network. Vary your solutions. Put some on LoRa, some on WiFi, some on Ethernet, some on ZWave, etc...