I have a group of sensors the nominally output 2.5V but if they come in contact with a magnet they'll increase slightly or decrease slightly based on the polarity (north/south pole).
These sensors have a decent range but they're pretty narrow in scope, so as a result I've aligned a number of them side by side.
My issue now is that I have 6 of them, and I don't want to spend 6 analogue in pins if I can help it. Ideally I'd like to build a circuit that ultimately reports the greatest difference from the nominal 2.5V between all 6 of the sensors.
For example, let's say we begin in a neutral environment -- no magnets are present. All sensors will read 2.5V and none of them really "win" the output pin. However, as I bring a magnet closer to the line of sensors, the one closest will read let's say 2.9V, and it's neighbour will read 2.7V. Between these two the 2.9V will "win" the output pin because it has the greatest difference from the nominal 2.5V. So I'd like to see either 2.9V on the output pin of this circuit, or 0.4V (the difference). Doesn't really matter which since the rest can be handled by software.
I'm thinking a summer op-amp might be the right answer here but I was wondering if you guys have any other suggestions. Thanks!
EDIT: To clarify, I don't care which sensor "wins" I just want to know if ANY sensors change from 2.5V, what's the greatest change?
EDIT2: There's only one magnet being sensed here so if one sensor reads negative then they all will. No need to account for some being +0.4V while another is -0.4v.