> PICers,
> Looks like I might have an actual job in spec - hah! I'd need to detect moving
> vehicles, I'd guess via their magnetism. Probably need to detect presence +
> direction of travel. Anyone had experience with devices for magnetic vehicle
> detecting that they'd wish to share? I'm mentally kicking round Honeywell's MR
> detectors. Are there other types on the market? Any tips most appreciated
> Thanks - Debbie.

Look at giant magnetoresistive sensors.  GMRs are extremely sensitive, 
and a hunk of steel the size of an automobile will almost certainly be EASILY
detected from several feet away.

The only manufacturer I know of is called NVE- www.nve.com (simply
enough!).  The parts can be bought at Digikey in onsie-twosie quantity.

A word of caution: these devices have significant hysteresis, and can
easily be damaged by large magnetic fields.  That said, most objects
which are ferro-magnetic will be registered, but WON'T damage them.

Mike H.

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