Does GPIO pins have any protection overvoltage (high voltage), amperage or other destructive behaviors of users ? maybe we should create a cheat sheet for working with GPIO
i found info https://docs.flipperzero.one/gpio-and-modules
It looks like the pins have a protection device on each one, on the drawing it looks like a varicap diode?
All GPIO input pins are 5V tolerant, but in some cases (such as in the bootloader) not all the pins are configured as such, so please be careful.
Using 3.3V should be safe, though.
i read each gpio have resistor, it can be some protection https://docs.flipperzero.one/gpio-and-modules#miFsS
The resistors are not enough for overvoltage protection. It may be some sort of overcurrent prot, though. 3.3V / 51Ohm = 0.06A = 60 mA (short circuit), and max for GPIO pins is 20mA.