It’s a fact that a car is an interference nightmare, but the ABS system can figure it out so the noise shouldn’t be a big problem. I am more worried about “radio signals” in this environment with all kinds of signals in a wide spectrum. Sure there are pros and cons with every solution and this can be turned over a million times and we will still be at square one.
...Sorry Ante, I didn't explain that well, I didn't mean electrical noise. I meant statistical noise, ie readings that vary naturally say +/- a few digits, and the true data varying only a few digits, so it is hidden in the information.
I would guess the data is compared as a trend, over a given span of time, then a choice is made wether or not the pressure is going down.
On the subject of 'the big boys' I do remember reading an article in the siliconchip magazine, but looking thru my collection I can't find it. But with my mag collection spread out thru many boxes it will take some time to unearth it. Off memory it was a maxim smd chip and it sat on the inside of the tyre wall. A pretty neat idea but the article was for the cars of the future so it looks like a lot of fun for us small blokes to come up with a similar idea.