Power select jumper

[hrh118]

I am trying to understand the purpose of the power select jumper.  Update 23 said "the Papilio DUO will not receive any power when it is plugged in until a jumper is located and placed in the FPGA or AVR position on the power select header".  Does this mean you can use either the Spartan FPGA or the Arduno micro controller and you can not use both simultaneously?  If you can't use the Spartan FPGA and the Arduino micro controller simultaneously what do you gain by adding an Arduino compatible micro controller to the Papilio Duo?

[Felix]

There are two usb ports.

You need to power from one or the other.

I would leave on FPGA side and forget about it until I needed to change it.

http://papilio.cc/uploads/Papilio/duopower-schematic.png

[Jack Gassett]

The power jumper protects in the rare case you are plugging in the two usb ports to different computers with differing 5V power supplies. By only allowing power to come from one of the USB ports there is never a chance for a conflict. Note, this is only the power, you can use the USB functionality of both ports at the same time. But if you only plug in the FPGA or the AVR then you need to make sure the power selector is in the appropriate position.

[hrh118]

Thanks Felix and Jack,

 

Thank you for straightening me out about the function of the Power Select Jumper.  My question was based on a faulty assumption about r the purpose of the Power Select Jumper.

 

Howard

[Felix]

anytime mate