What it does

So, what does the ArduAltiAlarm do exactly?  Well, it can be programmed to do different things.

The main goal was to cut-off the motor of an rc airplane at a certain height to show the pilot he/she was flying too high.  So this is the first function you'll find.

But what about a sailplane?  This airplane has no engine!  The goal is to provide a clear indication when the pilot is flying too high.  Mmm, let's move the rudder left and right in a constant motion to show the pilot that he/she is too high.

A third function was suggested, just because the hardware is capable to do it.  Let's make it ready to be used in the 555 competition.  The programming is very simular to the first function.  We just need an extra time constraint.

Last but not least, the first mode can also be used to do an automatic disconnection of a sailplane from the towing plane by releasing the tow hook at a specified altitude.  Changing the motor or changing the towhook servo requires an identical program.  In stead of creating a fourth option we just use the first mode and adapt the user manual to explain it all.