Hi,
I have an arduino pro powered by an external power. I need to have more power than with usb to power leds. Can I use the USB ftdi board simultaneously. It seems that there is no switch to commute between external power and usb power.... What's happen if I connect the usb ftdi board to the pc when the arduino pro is connected to an external power ?
kao
It seems that there is no switch to commute between external power and usb power
So what is S1 shown in the schematic?
it seems that this switch is for switching between external power and battery, not between (battery/external power) and power from usb cable.
Yes but the pro doesn't have a USB interface therefore the power from the USB to serial bridge IS the external or battery input. They both go to the 3V3 regulator.
What's happen if I connect the usb ftdi board to the pc when the arduino pro is connected to an external power ?
As long as the ftdi power is not connected to the Arduino then it is fine. Always connect the grounds together never connect the +5V together.
so if I use external power and the usb to serial connector (connected to a pc) .. I need to disconnect 3.3V pin on the JP5 connector? Is it right ?