Hi.
I have a problem, as i have made a project which uses the serial port (FTDI) to communicate with the computer, but the projects needs to be powered with an external power supply.
And it isn't possible, as the Duemilanove automatically selects the USB power supply!
How can i manually change that?
Best Regards
Thomas Jespersen
the Duemilanove automatically selects the USB power supply
No - it only selects USB if the external supply is not connected. If you connect anything greater than 6.6V it is automatically selected.
Also if i'm using the VIN?
Also if i'm using the VIN?
Yes, Vin can be considered the same as external power, it just enters after the polarity protection diode that wires to the external power barrel jack.
Lefty
Polaration Diode... Wouldn't that make a voltage drop of 0.6V? So the power can't be lower than 7.2V?