The next bit you can help with is in post 20 on page 2
Long story short, I'm tired of folks helping themselves to the fuel in my 18 wheeler. The tanks are situated under the sides of the vehicle and there is room above them to mount a sensor (possibly a PIR??).
I've looked into automotive style alarm systems. I just feel it would be overkill. If they want to steal the truck, so be it. I'll send them a thank you card. I've also looked into locking fuel caps. But they are easily circumvented by anyone with any determination at all.
I'm open to any ideas you folks might have. Basically, I want a sensor to activate if someone's hand covers the 4" diameter cap to take it off. When that happens, a very loud alarm will activate and some lights (parking and work lights possibly) will blink. At least that's the plan in my head right now.
It will, of course, be controlled by an Arduino. And probably just use relays for activating the alarm and lights.
I know very little about PIRs (Passive Infrared Sensor if anyone was wondering). So, is there a PIR that can handle Ohio winter weather? Of course, I could mount it inside a piece if 4" PVC pipe with a removable cap. Then just pull the cap off each time before activating the system.
Anyway, like I said, I'm open to ideas.