I've not heard any driver ask for this feature, but many have said it is ni= ce, because they can think less as they use the system. Keys in pocket, ge= t in car, drive off. The companies that provided the feature do benefit from new car sales after= theft. ;-) On Mon, Jul 09, 2018 at 05:10:25PM +0100, David C Brown wrote: > That is how they work. Hence the story of the driver stranded 300 miles > from home because he dropped the device in his drive after starting the > engine. >=20 > But, interesting as this technical discussion is, it begs the question of > why these devices are becoming so ubiquitous. Are drivers becoming so > indolent that pressing the button the key is just far too much effort? >=20 > __________________________________________ > David C Brown > 43 Bings Road > Whaley Bridge > High Peak Phone: 01663 733236 > Derbyshire eMail: dcb.home@gmail.com > SK23 7ND web: www.bings-knowle.co.uk/dcb > >=20 >=20 >=20 > *Sent from my etch-a-sketch* >=20 > On 9 July 2018 at 17:06, Van Horn, David < > david.vanhorn@backcountryaccess.com> wrote: >=20 > > > > So what would happen if you were driving legitimately and the keyfob > > battery died? > > I'd take exception to a sudden panic stop on the interstate. > > > > I suspect that once the vehicle is started, that they keep everything > > going till the car is shut down again for exactly that reason. > > > > > > > > -----Original Message----- > > From: piclist-bounces@mit.edu On Behalf Of > > Timmothy Relerford > > Sent: Monday, July 9, 2018 9:50 AM > > To: Microcontroller discussion list - Public. > > Subject: RE: [EE]:: Wrapping key-FOBs in tinfoil > > > > > > If the key fob was inside someone's house and a thief used some method= of > > repeating the signal to start the car and drive away, what happens aft= er > > they get some distance away? > > Does the car shut off? > > In other words, doesn't that fob signal have to remain in proximity of > > the car to keep it going? > > After all, if you're the rightful owner, and you have the fob in your > > pocket and you get into your car and drive away, no matter where you g= o, > > that signal will be in proximity of the car. After all, you're sittin= g in > > the front seat. > > But if the signal is being repeated, at some point, that signal will > > disappear. Will the car turn off now? If it does, then the thief wou= ld > > only get a short distance away before the car stops and he won't be ab= le > > to get it started again unless he copies the signal and programs a piec= e of > > electronic equipment to act as the fob from that point. I guess they > > could strip it or tow it after that, but that would seem risky to me. > > > > > > > > Regards, > > > > Jim > > > > > -------- Original Message -------- > > > Subject: Re: [EE]:: Wrapping key-FOBs in tinfoil > > > From: Denny Esterline > > > Date: Mon, July 09, 2018 10:25 am > > > To: "Microcontroller discussion list - Public." > > > > > > > > > > > > > > > > > > It seems to me the only way the key fob is going to be able to be > > > > copied is if someone presses one of the buttons to transmit the > > > > signal. If it is just sitting on a table or hanging on a wall hook= , > > > > how would someone outside the home (or bldg.) cause the key fob to > > > > transmit? > > > > > > > > > > > > > > > This is a misunderstanding. I cannot claim to know the underlying > > > technology, but many new car keyfobs today are "proximity devices". > > > Fob in pocket, press button on dash to start car. Definitely do not > > > have to press any buttons on the fob. > > > > > > I've not read Russell's linked article, but I did recently read an > > > article claiming thieves were using SDR as a repeater to significantl= y > > > boost the range of what the car considers "proximity". The claim was > > > with your keys on a hook by your front door, they could use a repeate= r > > > outside and drive the car away. > > > > > > The really fun trick here is they make no effort to capture or crack > > > any codes, just boost a signal. > > > > > > > > > -Denny > > > -- > > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > > View/change your membership options at > > > http://mailman.mit.edu/mailman/listinfo/piclist > > > > -- > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > View/change your membership options at http://mailman.mit.edu/ > > mailman/listinfo/piclist > > > > -- > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > > --=20 > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 James Cameron http://quozl.netrek.org/ --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .