I have a headless pi and I need a way to perform a clean shutdown in the event that I lose wifi access to the pi, something in the OS or one of my programs locks up the pi, or maybe I just don't have remote access at all and need to shut it down. So I am going to wire a momentary switch to one of the GPIO ports to enable a clean shutdown using a loop that looks at the status of the switch and then issues a shutdown command when it goes to low. I am also wiring a toggle switch to the 5v line so I can turn the pi power off after the clean shutdown and then on again to boot it up again. Note that I could just do a reboot with only a momentary switch, but I also want the capability to just turn the pi completely off. Anyway, this is all easily doable.
My problem is that the pi will be enclosed in a sealed box and will not be visible, so I have no way of telling if the pi is shutdown, and that it is safe to reset it with the toggle switch (I can't look at the on-board LED's). I was hoping to wire a led from either the 3.3v or the 5v GPIO pins to the front panel of the chassis, but the pi does not really shutdown like a x86 Linux computer does, meaning that all the power rails are still active after a shutdown.
So, any ideas on how I can detect that it has shutdown in such a situation?
My Raspberry Pi Project Page: