I’ve got issues with external powered USB hub. First of all I will describe my hardware list:
BeagleBone Black A5A
BBB’s power supply - 5V, 2.5A
media USB hub - http://www.media-tech.eu/products/USB-accessories/MT5082
external power supply for common USB hubs – 5V, 1A
My BBB is with default Ångström Distribution which comes with kernel 3.8.6, release v2012.12 (core edition).
What is going on?
After connecting my media USB hub to PC, everything seems to be perfect. When I will connect my hub stand alone, without an external power supply, It does blinks for few seconds, afterwards light flashes without blinking. At this moment, when I list my USB hardware using terminal, everything is fine:
Bus 001 Device 002: ID 1a40:0201 Terminus Technology Inc. Hub
Bus 001 Device 005: ID 0d8c:0008 C-Media Electronics, Inc.
Bus 001 Device 006: ID 0a46:9621 Davicom Semiconductor, Inc.
It does not matter when actually external power supply is connected in this state. It works flawlessly without any issues. But what happens when I connect it do BBB?
It’s drama and pain in an ass. When I connect into my hub mice and keyboard only, nothing happens. External power supply for hub as well as for BBB are both powered. Light in my hub doesn’t blinking or flashing either. Mice doesn’t flashing too, as well as caps-lock or num lock on my keyboard. I wonder is my hub over loaded, but – it’s not. On PC I added 3G modem which drains a bit of energy, and everything works. When hub is disconnected form BBB and standalone mice is hot-plugged – nothing happens. When I will do hardware reset using button on my BBB – finally – it’s redy to work.
In order to resolve an issue
I think I should give more technical point of view. Description such as this is not enough to resolve it. I haven’t any dedicated cable for BBB. I can not access logs, because hub does not works (so mice and keyboard either) or even sometimes BBB freezes before autologin procedure.
I have only common RS232 USB cable (I bought it to rescue hard drives), however – amount of jtag headers on BBB is greater. My cable have got 3 wires i colours: orange, yellow and blue. It’s displayed as Profilic Technology inc., PL2303 serial port. Does it fit for futher diagnostics?