Given that we have literally hundreds of unused arduinos sitting around is it possible to just use an arduino to create the signal on a loop? e.g. basically using a blink sketch or might need to manipulate the timer bits directly - any reason that wouldn’t work?
Also, so in the commercial invisible dog fence system they can alter the size/width of the detectable zone - what is it that’s being increased/decreased on those systems? Would we need to run the output from the 555 circuit (or the Arduino hack I mentioned above) into a transistor/amplifier to feed a variable voltage onto the perimeter wire? would that also be essentially the solution to David Ho’s question? Does higher voltage overcome, or at least extend, the distance limitation?
Thanks for the really great article!! I’ve been looking for something like this that explains the basics for at least a couple of years.