I'm not sure if I am in the right forum topic, but I just try.
I use an ATxmega128A4U with a bootloader and USB application. The device is working ok, I can communicate over USB, put the device into bootloader mode and do firmware update with the FLIP application.
But a few of the devices after a while "stop working". When they are plugged into a computer, they are either recognized as bootloader device or aren't recognized at all. So my basic question is, why does this happen? We do not know any cause preceding this behaviour.
So to split it up, two cases:
1. Device is only recognized as bootloader device. Normally, when I put the device into bootloader mode and then unplug and replug it to the PC, the application starts again. That does not happen in this case. It just stays in bootloader mode and can/has to be reprogrammed with flip e.g.
2. Device isn't recognized at all. I am only able to reprogram it via programming adapter and atmel studio. I can reprogram bootloader and application and everything is fine again.
Does anyone of you has similar experiences?? And more important: does anyone have any idea, what could be the cause of this or where to start digging for a cause? Could it be electrical or programming issues?
Any answer is appreciated and I would be happy to provide any further information needed.
It's a very bad thing if such behaviour appears at our customers abroad and they have to send back the devices...