Re: FTDI serial USB-TTL cable leds too bright

[adafruit_support_mike]

Hmm.. that would indicate communication between the USB hub and the FTDI chip but nothing going to the output.

The next place to check would be on the D+ and D- lines between the hub and the FTDI chip built into the cable, but you'd need a USB pass-through to get access to the signals.

It sounds like the problem is in the hub though. The cable behaves properly when connected to a computer or another hub. If the TX/RX lines aren't doing anything at the point where they meet the BBB, I wouldn't worry about them damaging the BBB. I'd probably unplug the cable to err on the safe side though.

[renatus]

Gavin Moore of FTDI suggests it would be best to power down the hub when the host is powered down.
I suggest Adafruit add this note to the website for the FTDI cable and Friend.

[adafruit_support_mike]

I'll pass that along. Thanks.