Neighbor's house alarm triggers when I put my car in reverse • Hacker News Board

Re: Neighbor's house alarm triggers when I put my car in reverse

#261

Post by roryisok » Mon, Dec 18, 2017, 5:08 PM UTC

Pharylon wrote: post #257

__david__ wrote: post #225

Earlier quoted context omitted.

My dog was similar, but the sound he triggered on was the CRT turning off. You could sit perfectly still and press the off button the remote (so as not to give any body language signs) and he'd wake up, and wander off to the bedroom for the night.

When I was young and my hearing was better, I think I had a slightly-better-than-normal upper end to my hearing. Often, I would hear CRTs whining that no one else did. I vividly remember when I realized it. One day in class we were watching a tape and the TV was whining the entire time. After the tape was over, the teacher started talking about what we'd seen, but didn't turn the TV off. I asked him to, because the s…

Same here! I remember waiting for a lift where my friends mother worked, a car rental place. I told her I could hear a TV on somewhere, and she insisted there was no TV nearby. I persisted, it was driving me nuts. Finally, she remembered the cupboard above our heads had a TV in it. She opened the cupboard, and low and behold, it was on, on mute. I felt like I belonged in the X-Men.

Re: Neighbor's house alarm triggers when I put my car in reverse

#262

Post by detaro » Mon, Dec 18, 2017, 5:09 PM UTC

roryisok wrote: post #260

digi_owl wrote: post #212

Earlier quoted context omitted.

Makes me think of a story i ran into somewhere about a secretary that had sorted all the files on her office PC in different folders alphabetically. This was back during the DOS days, and i suspect it was only discovered when she complained that it would no longer start in the morning. It may well be that said joker had the best of intentions by sorting the keys in the numerical order...

I've read this seven times now and I just can't understand it. Can you elaborate?

I assume it means that they neatly filed COMMAND.COM in folder "C", and AUTOEXEC.BAT in "A", ... No filesystem permissions or file locking to prevent you from ruining your system in DOS.

Re: Neighbor's house alarm triggers when I put my car in reverse

#263

Post by SAI_Peregrinus » Mon, Dec 18, 2017, 5:12 PM UTC

Klathmon wrote: post #32

ZeroGravitas wrote: post #29

Earlier quoted context omitted.

I'll add a related real life debugging tip I've seen play out at least twice in the real world: If you can't get an alarm to shut-off or stop beeping, no matter what you try, then give serious thought to the possibility that there's a second alarm nearby which is the source of the noise.

About a year after I moved into my previous house, we heard that familiar chirping sound. After 3 goddamn hours of searching, and having run to the store to buy 9-volts and replaced every goddamn battery in the house, we found a carbon monoxide alarm thrown INSIDE the return air duct of the HVAC unit...

Which is a reasonable place for one, as it will trigger from excess CO anywhere in the house when the HVAC is running. The problem is only obvious when you're not the original tenant who installed the thing.

Re: Neighbor's house alarm triggers when I put my car in reverse

#264

Post by legohead » Mon, Dec 18, 2017, 5:13 PM UTC

m52go wrote: post #47

Got a kick out of this gem from the reddit comments: > My S2000 car alarm would be set off whenever I microwaved blueberries. Some experimentation revealed it was anything with excess water. Buying a new microwave solved the issue but I don't like thinking about how poorly shielded the old microwave was. I tried moving the for further from the kitchen or keeping the keys far away to no avail.

When I lived with my brother and played a lot of WoW I would get disconnected almost every night at around the same time, and usually in a Raid which was quite annoying.

Eventually I tracked it down to microwave usage. Whenever the microwave was in use, I lost WiFi.

Re: Neighbor's house alarm triggers when I put my car in reverse

#265

Post by vxNsr » Mon, Dec 18, 2017, 5:31 PM UTC

AndrewHampton wrote: post #226

remyp wrote: post #82

This reminds me of a “bug” I found when working for a company that sells package lockers to apartment buildings. We used iPads for the user interface and had monitoring in place to alert us if an iPad went offline. At only one location with two iPads one would go offline almost every day (but not every day) between 12pm and 1pm, for 10-20 minutes. Never the same time of day, and never the same length of time. It was…

This reminds me of a story one of my college professors told about the days when he helped automate factories in the 80s. Every night, the control server hey installed would go offline around 1am then come back up a few minutes later. It was never the exact same time or duration. After a few days of diving through the code with no progress, one of his co-workers decided to stay up all night at the factory and just wa…

There's a lot of permutations of this story including life support systems in hospitals I find them all apocryphal. The cleaning staff would notice right away if they just shut down a huge computer. Esp. in the 80s I doubt it even used the same outlet as a regular vacuum cleaner.

Re: Neighbor's house alarm triggers when I put my car in reverse

#266

Post by jmcgough » Mon, Dec 18, 2017, 5:34 PM UTC

mabbo wrote: post #229

DonHopkins wrote: post #209

I posted this before in the "My wife has complained that OpenOffice will never print on Tuesdays" discussion [1], but it's worth repeating: I heard a story about a terminal in a public terminal room that a user was able to consistently log in to if they were sitting down in a chair in front if the terminal, but never if they were standing up. They thought it might be static electricity, or some mechanical problem, or…

Had something like that over a decade ago doing tech support for a government reporting agency. Report: "If my secretary logs with our account, it works. If I do, the website logs in but then later shows me errors message when I try to submit a report".[0] Entirely repeatable. Screenshots sent showing it exactly. All of us scratching our heads. How could our web server know who was sitting in front of the keyboard? R…

I had a similar experience with a bug in a SaaS product that integrated with bank websites. They would send us the user ID and we would use that to determine whose account to log them into on redirect (and create a new account for the user if we hadn't seen the ID before).

At some point it became clear that they ignored leading zeroes during login on their end, but still included those leading zeroes when they sent it over to us, so we had a number of duplicate accounts. I purged the duplicate accounts (delete the newest, strip the leading 0s off the oldest) at the same time that they changed their code to send over the truncated number. All went perfectly, except apparently a few spouses were upset that they could no longer use their secondary account.

Re: Neighbor's house alarm triggers when I put my car in reverse

#267

Post by thecrazyone » Mon, Dec 18, 2017, 5:38 PM UTC

smlacy wrote: post #130

chrissnell wrote: post #124

When we were kids (dating myself here), my friend had a TV with a remote control back when almost nobody had a TV with a remote. You would push the channel-change button on it and the channel knob (!!!) on the TV would mechanically turn and the channel would change. Well, apparently, the remote used an almost-audible high frequency to signal a channel change and when his dog ran through the living room, the dog's tag…

We had one of these as well -- a fairly standard routine of TV after dinner before going to bed quickly taught the dog that the ultrasonic sound made by the "Off" command to the TV meant "everybody go upstairs and go to bed". You could actually just press that "off" button at any time, and the dog would look around and do that funny "Dog shrug" thing they do, and go upstairs and lie down, even if it was the middle of…

Haha "remote controlled dog" was funny. You've recreated Pavlov's experiment albeit updated it for our tech century :D

Re: Neighbor's house alarm triggers when I put my car in reverse

#268

Post by timzentu » Mon, Dec 18, 2017, 5:41 PM UTC

vxNsr wrote: post #265

AndrewHampton wrote: post #226

Earlier quoted context omitted.

This reminds me of a story one of my college professors told about the days when he helped automate factories in the 80s. Every night, the control server hey installed would go offline around 1am then come back up a few minutes later. It was never the exact same time or duration. After a few days of diving through the code with no progress, one of his co-workers decided to stay up all night at the factory and just wa…

There's a lot of permutations of this story including life support systems in hospitals I find them all apocryphal. The cleaning staff would notice right away if they just shut down a huge computer. Esp. in the 80s I doubt it even used the same outlet as a regular vacuum cleaner.

Some of them even had the mains wired directly into the case, so you couldn't unplug without an ax.

Re: Neighbor's house alarm triggers when I put my car in reverse

#269

Post by moftz » Mon, Dec 18, 2017, 5:43 PM UTC

mikestew wrote: post #28

lb1lf wrote: post #11

Is it just me who'd love something like this to happen to me? Would be great fun tracking down the source of the problem (if it was my car; probably less so if I was in the house...) There's a lot of options to try to isolate the problem, just thinking out loud here - a) Back into the driveway returning from work. See if alarm goes off. Next morning, see if alarm goes off as you drive out. b) Remove fuse for reverse…

Of what little I read of the reddit thread, there must not be many gear heads in there that debug software, too. I say that only because there is a lot of “it’s probably...” but no “try this, which will eliminate $FOO. Next, $BAR, which eliminates $FOOBAR.” For your list, and I’d do a) and not bother with b) and c) as a) eliminates them well enough (point the emitters away from the alarm sensors). For d), I’d put a l…

Seems like there are two possibilities: engine noise is causing windows to vibrate making a sensor go off or the reverse distance sensor that uses microwave radar (X band) is causing the base unit to think a sensor is going off. It is a WRX (lots of rumbling engine noise) so I would imagine that the first scenario is more likely. A home alarm system is most likely going to be 433MHz (or even the wifi/bluetooth bands) but not X band.

Re: Neighbor's house alarm triggers when I put my car in reverse

#270

Post by rurp » Mon, Dec 18, 2017, 5:43 PM UTC

Last year a co-worker frantically came over to tell me that text was disappearing from her computer screen. I walked over to her desk and watched as she began to type an email. Sure enough, the characters she entered went away one at a time. I glanced down at the desk and gently lifted a headset that was resting on the "delete" key of the keyboard.