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How does this work, RFID tags embedded in tyres?

From https://www.tyrepress.com/2014/01/formula-e-tyres-to-feature...

> “These RFID chips will be embedded in the tyres’ sidewalls to ensure their traceability, from their production right through to their return to the factory after use at the racetrack,” explains Serge Grisin, manager of Michelin Motorsport’s four-wheel programmes. “Traditionally, this information is collected using an optical bar code reader. These new electronic tags open up all sorts of possibilities in addition to simply identifying individual tyres. They will be able to collect data relating to running conditions including temperature and pressure sensors. It will be possible to record and access information covering the tyre’s entire lifecycle.”

Identifying - sure. But how do they get temperature and pressure information? Is there a microcontroller embedded that writes stuff to the tag?

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This seems like (clearly?) bad journalism. RFID tags on their own are for sure not taking active sensor readings, that'd be left for something closer to TPMS style systems.

It seems there are RFID tags that provide sensing functions. I didn't do a deep dive, here's the first thing I found. [1] They sense temperature, pressure, and other parameters. I wouldn't be surprised if something like this is used by tire makers.

[1] https://www.atlasrfidstore.com/sensor-rfid-tags/

But RFID are unique, read-only keys burned in to silicon at time of production.

Perhaps the car is using Wi-Fi for TPMS.

They don't use Wi-Fi.

There's a small battery-powered device mounted inside the tire, attached to the valve stem.

In regular passenger vehicles, it's usually woken up regularly by a signal from the car. It takes sensor readings, and transmits them back to the car (using that region's unlicensed UHF bands).

I imagine Formula teams may have need for greater frequency of sensor data, so there could be some variations here, but that's broadly how it works. In a passenger car, the battery outlives the tire.

https://en.wikipedia.org/wiki/Direct_TPMS

Thanks for the explanation.

> In regular passenger vehicles

So this system gets abused in sports. I wonder if there are applications in the real world (like tracking of movement of (individual) cars).

So this system gets abused in sports. I wonder if there are applications in the real world (like tracking of movement of (individual) cars).

It's already done. When you drive into a parking lot, or go through a restaurant drive-through, your tires may already be scanned and your information sold.

It doesn't take much to corollate a person using the same credit card more than once at a store with the transmitted IDs of their tires in the parking lot, and then follow that person, via their tires, from place to place as they shop, do errands, visit an abortion clinic, etc.

How do you prevent this

Cash, and transit. That's about it.

A lot of TPMS are basically just specialized RFID systems. Some don't even have a power source for the tag.

Active RFID tags with integrated sensors are becoming more common.

Electronic sensors of various sorts have become low enough power to enable embedding a very small battery with sensors and RFID transmitter. These can log readings every second or few for a few _years_.

Are there antennas in car wheel wells? The main car battery can probably power it with a correctly calibrated antenna.

See my other comment for a simplified explanation, or check out https://en.wikipedia.org/wiki/Direct_TPMS

Temperature seems like it could be easy, I think you could do that analogue style with a passive tag connected to a bimetalic wire through a transistor.

But in reality they probably intend to use a UHF WISP e.g. embedded micro-controller.

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