4 years, 11 months ago.

simultanous communication and power with usb kl25z??

Hello in a project I am using USBDevice library to have a virtual uart using USBSerial. The problem is that iIwant to have the possibility of communicating throught USB but nearly all the time the USB will be just a power connector.

If I compile with USBDevice support plugging "power only" makes the micro not booting. Perfectly boot when the cable is plugged to a Computer USB port.

If i remove the USBDevice support the micro boots with "power only" and also connected to a computer USB port, but I have lost the chance to communicate with it.

I am gueessing that some pull-up in the D lines is needed and not configured when I try the "power only" option but I do not know how to find that.

Any ideas

Question relating to:

USB device stack device, USB

1 Answer

4 years, 11 months ago.

The problem is that by default it will block until it is connected. One of the arguments in the constructor can change that to non-blocking. Then it will start fine in both situation (at least it should :P).

There is something like .isConnected() (check the API for what it is exactly) which will tell you if it is connected. The part however what might be a problem is how to handle disconnects and subsequent reconnects. If that isn't required for your application then you don't have to worry.

Accepted Answer

Actually the functiion is .configured().

Thanks!! Now it works as expected

posted by Oskar Lopez de Gamboa 05 Jan 2015