Electronic – Atmel Chip not recognized as USB device. How to troubleshoot

atmelavrbootloaderusb

I've soldered the AT90USB1286 Chip on a PCB like on this circuit: Imgur

Schematic

If I measure the pins, caps, resistors etc. with a multimeter, everything seems to be powered and fine. Reset button pulls to ground. And yet, the computer doesn't recognize any USB device when I plug the USB cable in.

I've tried it on Mac and a Linux PC. lsusb doesn't show anything new after plugging in. Same goes for Mac.

Does anyone have an idea how to troubleshoot this? How to get this chip recognized over USB? Thanks a lot.

Best Answer

Leaving the Vbus pin floating seems a bit strange.

The datasheet shows this configuration: enter image description here

None of the configurations shown in the datasheet leaves the Vbus pin floating. Just try connecting it up and see if that helps anything.

Related Topic