It still kinda software, but it is at least boot related, but I would maybe improve it and just set specific pin high:That requires software, I need detecting on hardware level that doesn't require any specific software running on the device that is being checked.
Are you willing to make a minor change to its config.txt and do you have any of the possible UART pins free?
If so, enable one of the UARTs (see /boot/overlays/README) and have the other Pi monitor the UART's TX pin. As long as you don't run a getty on it it will go high once activated (TTL serial is active low) and low on shutdown.
What it won't let you do is distingush between a active Pi and one where the kernel paniced or the OS has hung in some other way.
Code:
gpio=17=op,dhStatistics: Posted by exander — Mon Sep 02, 2024 12:10 am