Re: Faraday bags and other scarey things (2023 Update)

Booster is a small thing, not something big. It also doubles down as power bank that can power/charge your cell phone, tablet, whatever. Small thing, you won't even notice it in your trunk. Fits in the glove box if needed. Here is mine:

Very useful gizmo, highly recommended. I only used it twice, once on my LS460L when [old] battery discharged in the vehicle sitting idle for a week and once on my wife's KIA Sedona (V6) that had battery failed suddenly. In both cases it allowed to start the engine and let my wife drive to Walmart for a battery replacement.

I also carry a small 12V air compressor, not big deal but sometimes it's a lifesaver. Roughly the same size as a booster. When ambient temperature changes significantly tire pressure goes out of range and both Lexus and Kia start complaining (they have sensors on all 4 wheels, Lexus has 5 -- it has a full size tire, not that tiny rubber bagel only good to drive to the closest tire repair shop, as a spare and checks its pressure too).

Proximity sensor, very short range.

I doubt it.

Put the fob in the bowl and walk towards the car.

If my car had a dead battery, I could unlock it with my real key and boot it up from my little lithium thing. Or at least get inside, out of the rain and snow.

Imagine freezing to death because your car won't let you in.

Good idea, and now it's warm enough.

The car being tested is a 2018 Honda CR-V.

The bowl did reduce range if one pushed the lock/unlock buttons using a 9" wooden stick (versus one's finger), but not enough to solve the problem I'd guess.

Bowl is made of spun 0.0355" thick brass, open top diameter 7.4", and depth 3.3". Base, also same kind of brass, is soft soldered to the bowl, looks to be done by hand with a big soldering iron (not a torch). Quite old, has no markings whatsoever, likely US made.

Also tried a 12" square sheet of 0.062" thick brass - same result.

A cover ought to help, but this will take some fiddling to be able to push the buttons through a solid metal sheet. Although I do have some copper insect screening that could be pressed into service. One can also make a bag from this screening fabric.

Longer term, I think that the entire class of man-in-the-middle attacks on key fobs will be solved by moving to some kind of ultra-wideband signal, where one can measure round-trip time to with picosecond precision, using a crypto-key sequence that cannot be deduced from received signals fast enough to matter, thus allowing too-distant fobs to be ignored with sufficiently low leakage to make this kind of attack unprofitable.

Joe Gwinn

Yes, I run into that problem all the time. Dead battery, no key, no place to go. I've actually died from this a dozen times. I must have more lives than a cat!

Larkin really is phobic when it comes to BEVs.

Why would you need ps accuracy in measuring round trip time? The distance you are trying to discriminate is around 100 feet, so 200 ns which can be done with a 40 MHz oscillator. There is no need to know to the foot, how far away the key is. Just is it more than 100 feet or so.

What I'm more worried about is the damn thing opening a door inadvertently while I'm still not far away. I returned to the car from shopping and while I was putting things in the trunk, someone was admiring the gull-wing door that was open. I must have pressed the button on the key fob while it was in my pocket. That can happen from quite a distance too.

Why not make people push a button on the fob to unlock the car?

Because this would defeat all hands-free uses, which most customers are quite fond of.

Joe Gwinn

The distance from my kitchen to where the cars are parked outside (and thus accessible to would-be thieves) is well less than 100 feet.

And picoseconds are easy for UWB technology.

There is actually a use case that requires knowing the range: For remote-start (very useful in cold places), the range may well be large, but this does not unlock the car, so one can require no more than six feet for opening and two or three feet for driving away.

I've had that problem, and what mostly works is a silicon-rubber pull-on case, which makes the buttons far harder to activate.

Joe Gwinn

You are saying you need what distance? What timing. Clearly, you don't need fractions of a foot, so not ps.

Who cares? It's not needed.

Actually, my car automatically opens the car door when I approach. From the rear, the door opens when I am about at the rear of the car. From the front, it opens when I'm about 3 feet, and only opens a crack, or it would be in my way. Then as I walk past the door, it opens the rest of the way. Very handy when my hands are full.

So I guess they've solved this issue without UWB tech. The battery in the fob lasts around a year.

The buttons are already hard to press. They aren't buttons in the sense of a knobby thing sticking up. The fob is shaped like a car and you press the appropriate surface to open doors and trunks. Where the buttons are is not all that obvious and they can be hard to press because you aren't in the center of the button. It's another one of the Musk "cool" features that don't work very well.

If you removed all the pointless gimmicks from the car, the many things that don't work very well, it would be a nice car. But they stumble over their own feet with a lot of the beta features that just don't work well enough to be ready for prime time.

The other big thing, in my opinion, is the huge touch panel. I love having a big map to view, but it is so much better to have buttons and knobs for the basic things like the heating. I like the autopilot, because it gives me enough time to find the buttons on the screen and get them pressed. When you have a touch panel that has to distinguish a touch from a swipe, that is hard to do in a car, when it's bouncing around. You can use a phone, because you can brace your hand at the phone. I have to use my arm extended to reach the touch panel, resulting in the hand moving up and down with the road. Not every road is a glassy superhighway.

I think at some point, either the government will restrict the use of touch panels, or consumers will, by buying cars with a less techy interface.

Most of the controls get used once in a blue moon. The heater/AC and radio... I mean, entertainment center, get used on every drive.

Are other cars this hard to use? My Kia has a lot of the needed controls on the steering wheel.

Oh, don't doubt it. Metal in proximity is all it takes to bollix a signal. At the metal surface, E field is zero. I missed a lot of phone messages once, because I left my cell phone on a copper-clad counter. Felt a little silly when I was told no one could get in touch.

Yeah, talk about solving a non-problem.

Cheers

Phil Hobbs

So the choice is car-free.

My RF key fob has a little (mechanical) button that, when pressed, a metal key pops out! That will open doors even if all involved batteries are dead.

I got a little lithium battery jump starter as a backup. USB rechargeable. It has USB power out too. I don't have to mess with jumper cables to start my car, or someone else's car.

It claims 1000 amps, which is improbable, but it started my V6 Audi when it was cold and had a bad battery.

I'm impressed at what great mechanisms are mechanical keys and locks. And how much bad code is around.

Joe tried it.

Third has lived a sheltered life. ;)

We built a couple of test stands for our fire and spark sensors used on cotton harvesters. The testers are built in a large die-cast aluminum stomp box with six screws in the lid.

The Raspberry Pi inside has no trouble communicating to a nearby laptop via wifi.

For really effective shielding, you want an uncoated paint can, an old nickel-plated 70-mm film can, or a Danish Butter Cookies tin of the right sort, i.e. where the printing doesn't cover the sealing edge of the tin and lid.

Oh, or a stomp box with a metal mesh gasket.

Cheers

Phil Hobbs

I have one of those too.

This sounds worthwhile. Modern cars are actually too big for their batteries, by a factor.

What make and model?

Yes. Bob Pease's comment was that his best programming language was solder.

Joe Gwinn

The Project Farm guy (Todd) has done a couple of jump-box comparos that are worth watching (at 1.75x, usually).

?v=5zAgL2L4ILY Cheers

Phil Hobbs