Hi I know this has been touched on a few times but i'm really trying to understand how this is actually going to work.
I have built a small 7805 external power supply with a distribution bus for all the items I need to power outside on the nano.
I would also like to use the usb port for serial data...
How does the zener autoswitch? Is it really highest voltage wins? I can see from the schematic that is its across the VCC and USBV. How best to ensure that the external regulator always wins, and will i then have problems powering the ftdi chip?
When I power the nano from the usb I see I get +5v on the vin pin wrt ground on the nano.
Thoughts with pics below (ive drawn on the power lines as I planned)
thanks in advance...neil