1. When active, output sinks to GND. Max 100mA. When not active, output is floating.
2. Pull to GND to activate input.
3. Pull to GND to reboot the camera. Not needed for most applications. Keep floating to avoid unexpected restarts.
4. DIO GND is tied to GND through a thermal fuse. When connecting the OV20i’s digital I/O lines to a system that is powered from a different power supply, use this pin to tie the grounds together.