Hello,
I have a machine that I am controlling through serial with a budget 10" unisurf tablet. It comes with a separate power supply, which I need to use as I can't charge through USB when it is plugged into the Arduino (obviously!)
However, as soon as I plug in the power supply, the serial connection stops working. It shows in device manager as COM3, and the arduino software allows me to bring up the serial window, however it neither sends or receives any connections.
Alternatively, if I plug the power supply in first, then the USB, Windows says 'USB device not recognised'.
Both these issues do not occur without the power supply.
Any ideas?