I've a pcb with an ATSAME70 on it. Some pins are connected to MOSFETS which switch larger peripherals - for example a siren.
This is my problem:
While reset and after startup, all GPIO seem to be configured as PIO with Pull-Ups. So there are 3.3v at the pins until my program reconfigures the pins, which leads to an short (annoying) activation of the siren every start... Is there a way to configure the chip (fuses?) to choose another default configuration? High impendance state would be nice, as it was with the Atmegas.
For the sake of completeness:
The MOSFETS have 100kOhm Pull-Downs at their gates. So the real voltage at the problem situation is at circa 1.7v, which is high enough to switch. Yes, I could use lower Pull-Down values (like 10kOhms). This would lead to circa 0.3v (assuming 100kOhm internal Pull-Up value). But I would prefer no voltage (HI-Z state) at pins until they are configured.