BBB does not recognise USB connected Arduino2009 if this is self powered

Problems arise anyway after random time with ftdi USB-RS232 adapters.

If I connect a self powered HUB or self powered Arduino I can ear something become noisy: “zzzzzzzzzzz…”.

Is this a known problem ?


I have not heard that noise before.



It is a noise from a socket type power adaptor.
What really matter is that BBB does not more recognise USB, even if reboot.

I tryied many USB-RS232 adapters (without external powering USB slaves).
The connection is unstable.
dmesg show ftdi related problems (unable to change speed or other iocntl).

BBB is powered with only 1A adaptor.
I’ll try a better one.

With a new power adaptor (BBB side) no more noise, but same problems.
When reboot BBB does not more recognize USB port, and the connected arduino USB-serial.

Unplug arduino power and reboot via software: BBB does not reboot.
Press reset button: BBB restart, recognize USB, exchange data with arduino.

But I need Arduino self powered.

Nobody else had the same problem ?

Using RevC produce similar problems.

New power adaptors, same problems.