Do you know if they also monitor bluetooth devices?
Like all cars have one and if should be detectable.
Also, most recent cars have DCM which are always sending data, including position to the car maker.
Like all cars have one and if should be detectable.
Also, most recent cars have DCM which are always sending data, including position to the car maker.
Didn't even cross my mind...
What possible reason is there for them not to just be plugged into the car's power and computer? I'm sure there is a reason, but it never once occurred to me that that would be the case. What a strange system.
The part where they are a sensor in a wheel and therefore have constant turning. Are you interested in engineering a system that can cheaply and reliably provide power and signal through a constantly and one direction turning joint? That's not a trivial problem, and most solutions are things like contact brushes on a turning bearing surface which would instantly foul in a tire and brake dust filled environment or a sealed puck of mercury channels that nobody wants to install on every single car in the world.
There are two ways tire pressure monitoring is done. The normal way is to piggy back on the tone wheels that ABS uses to monitor wheel rotation speed, as a flat tire has less circumference and therefore rotates faster. This has the down side that you need to "calibrate" it and people suck at doing that, it can't tell you raw pressure values at all, and for a while it wasn't normal for cars to have 4 independent ABS tone wheels so you couldn't always pinpoint which tire was flat. This method has no consumable parts, has no batteries, and sends no radio signals so is not trackable.
The other method is putting a battery powered pressure sensor and radio in the valve stem of each wheel. This method is retrofittable, will always give you raw pressure values and doesn't need any calibration (but does need pairing). However, the parts are more expensive, they are somewhat consumable and make tire changes more expensive and time consuming, and are constantly sending trackable signals that can be automatically dragnet surveilled. Don't buy this method.
https://www.ryanohoro.com/post/spotting-flock-safety-s-falco...
This has not been my experience.
Oh dear.
I think you will find a directional antenna can rather increase this by several orders of magnitude.
Those overpass things with cameras and transponders can definitely still pick it up within this range.
Plus like many have written, it's not even difficult to extend that range with cheap hardware.
The real fun part at the time was that every Bluetooth device pretty much was always in pairing mode, and that MACs didn't rotate...
Eventually those both happened, but in ways beyond my comprehension (I worked on the software side), the hardware guys could still pick up the signals to track cars.