Reminds me of "story of a car that wouldn’t start every time its owner bought vanilla ice cream".
http://www.kepner-tregoe.com/blog/help-my-car-is-allergic-to...
Neighbor's house alarm triggers when I put my car in reverse
161–170 of 316 posts
Re: Neighbor's house alarm triggers when I put my car in reverse
#162What I would pay to hear this on Car Talk. Sigh.
This sounds like the kind of thing they should mention on ATP (http://atp.fm/ - nice podcast if you're into tech, especially Apple)
Re: Neighbor's house alarm triggers when I put my car in reverse
#163Along the same lines, I had a hell of a time tracking down the reason my washroom GFI (ground fault interrupter) tripped on random occasions; i.e., the electric outlet would lose power and need to be reset. It turned out that an iPhone receiving a phone call tripped it -- even before it starts to ring! Making a phone call didn't do anything. Here's a 13-second video: https://vimeo.com/247730625 I'd love to hear comme…
The timing sounds like RF interference. I worked in TV a while back, and we were not allowed to have any cell phones (even silenced) on set - they would introduce this crackling sound into lightly-shielded cables near them. The interference would kick in about a second or two before the ringing started, because there's probably some handshake/setup before the receiving phone decides it's actually an incoming call. In…
My layman understanding of the old GSM network is that cells have a control channel that is used to set up calls (and initially also transfer SMS, before it became popular enough to DOS the cells) and then a bunch of channels for handling the actual calls.
It may well be that the control channel's initial "wakeup" transmission is done at a very high power to ensure the phone receives it clearly, and then after some back and forth the two adjust their power levels and move to a different channel for the actual call.
Re: Neighbor's house alarm triggers when I put my car in reverse
#164When 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…
I remember when I was a child than my next door neighbour had a remote control on their TV, which was connected to the actual set via a 5m thin cable. I thought it was pretty cool that she could sit on her chair and change the channel & volume without getting up. I suspect that if a dog had been involved that cable would have quickly become a tangled mess! (I'm not sure how common "wired remotes" were, that was certa…
I only ever saw one wired remote to the best of my recollection. It was on an old Sony Beta tape deck my parents owned. (This is from the 80s as well.)
Re: Neighbor's house alarm triggers when I put my car in reverse
#165When 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…
> the dog's tags would jingle
What does this mean?
Re: Neighbor's house alarm triggers when I put my car in reverse
#166Two related things-that-should-not-be-related bugs that I have encountered: The WiFi on my girlfriend's laptop would fail when an HDMI cable was plugged into the laptop. Changing the channel on the router "fixed" it but we never could figure out the ultimate cause. I can pause my Roku box using the Kodi remote app on my phone. This occurred when I inadvertently used the wrong remote to pause the Roku. It appears only…
No engineer, but i suspect the WIFI and hdmi stuff is RF related. Someone did a poor job on the laptop wiring and the HDMI is leaking noise into the WIFI antenna or something.
Seem to recall reading about similar issues related to WIFI and USB3.
As for the remote app stuff, i guess it's time to break out the packet sniffer.
Re: Neighbor's house alarm triggers when I put my car in reverse
#167When 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…
> the dog's tags would jingle What does this mean?
Metallic dog tags make a jingling sound when the dog moves.
Re: Neighbor's house alarm triggers when I put my car in reverse
#168When 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…
> the dog's tags would jingle What does this mean?
The metal pieces would hit each other creating a jingling sound.
Re: Neighbor's house alarm triggers when I put my car in reverse
#169When 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…
> the dog's tags would jingle What does this mean?
I presume, the dog was wearing a collar with some metal tags that bounced off of one another, making sounds of similar frequency to the ultrasonic remote.
Re: Neighbor's house alarm triggers when I put my car in reverse
#170Someone explained it properly in the reddit thread, it's the exhaust generating noise while driving in reverse (only happens in the morning when cold and at specific RPM, exhaust generates a specific frequency which vibrates the windows and triggers the alarm).
> Someone explained it properly That's a hypothesis, a very good hypothesis, but the Reddit thread and Hacker News offer many other reasonable-sounding hypotheses. I can't tell you the number of times I've tracked down a bug or other type of malfunction where I was 100% sure of the cause since my hypothesis made so much sense, but it turned out to be wrong. It was something else.
Alternative hypothesis, for the sake of example -
Someone's just really be into practical jokes. Possibly the neighbor whose alarm keeps going off, or possibly a third-party who found an easy way to trigger the alarm.
But, my first thought on this thing triggering when he backs up is a rear-view sensor that uses a projection to get data. Apparently the 2018 version of his car has radar sensors that go off when backing up (https://www.subaru.com/engineering/safety.html):
> Rear Cross-Traffic Alert uses radar sensors to help warn you of traffic approaching from the side as you are backing up, utilizing an audible warning and flashing visual indicators in your side mirrors and Rear-Vision Camera display