I need to know the best way to perform the following function using very energy efficient methods so that both the units may be battery powered.
Details:
There are 2 units. The base unit stays in place. The secondary unit is mobile. If the secondary unit gets more than about 10 meters from the base unit, I need the mobile unit to sound a piezo alarm.
There will be a couple of inputs to the base unit before it is "active" and needing to be within range of the secondary unit. That part is no problem. I'm just not sure the best way to alarm once the max distance is reached.
After more research, I came across the electronic leash technology. That is pretty much what I need, but I do appreciate the replies.
As for KE7GKP's question: I don't want the "leash" active all the time. Only when certain criteria has been met.
So, for a silly example:
IF it is between 8:00am and 5:00pm AND
IF Jane is sitting at her desk, AND
IF her laptop is not within 30 feet of her then sound an alarm.
This is not what I'm doing... just a silly example.
I need the Arduino simply to build a proof-of-concept. Once I do that, I will work with some Engineers to come up with a better prototype.
I'm using the Arduino for the proof of concept because I sort of know how to program it so it makes life easier. Although, I do wish I could program it with Ladder Logic I'm much better with PLC's
I'm much better with PLC's