INTERNAL USB HUB MOD

To install USB devices internally, more USB connections were needed.

I looped into the regular USB-ports and routed the D+/D- signals from the southbridge (IO controller) to each USB hub. The on-board port I hooked into was then connected back to the USB hub. By installing two new USB hubs, I got 6 free internal USB connections I could use for devices (2x USB hubs = 8 ports, minus 2x on-board USB-ports = 6 ports).

Having two storage devices, flash drive and SD card reader, on the same upstream connection is not a good idea speed-wise, therefore I put one on a separate hub. More information about USB hubs over at Wikipedia.

The reason I choose to hook into the USB-port and leave the spare mini PCI-express USB connection alone is that I want to:

For the type of hub, I went for as small as I could find. The one I found on Ebay was a Somytec mini USB 2.0 hub with four rotating connections and one upstream connection sticking out from its side, also a red power LED and external power connector. There are different variations of the rotating/swivel hubs, watch the discussion about swivel hub wiring diagrams to find a hub with good build quality and provides 500 mA per port.

It goes under various names, here are a few I found:

There's also a model with integrated SD card reader. Mine features a Genesys Logic GL850A USB 2.0 chip. The chip runs off 3.3v but I couldn't find a easy way to connect 3.3v directly.

UsbHub

UsbHub

After cracking the case open, I stripped all the unnecessary parts from the circuit board like the LED and external power connector.

Top and bottom:

UsbHub

UsbHub

The position of the first hub is directly under the touch pad, next to the memory slot. It fits nicely between two SMD chips and it's not touching the memory socket or covering the microphone hole. Placing it in the middle of the Eee motherboard allows for short data signal wires to the devices.

The wiring is quite simple, there are foure pads, the square one is pin 1 and power. The pinout is: 1 power, 2 d-, 3 d+, 4 ground. An easy way to think of the pinout is to remeber that d- is next to something positive (power) and d+ is next to something negative (ground), the opposite of the data signal.

UsbHub

The second hub is covering the SSD NAND flash chips. The underside of the all devices is insulated by electronic tape to avoid possible shorts.

UsbHub

The total height is still low enough to not touch the chassis.

UsbHub

UsbHub

UsbHub

I hooked into the two USB ports on the right-side of the Eee to provide the data signals to the hubs. One of the four ports on each hub is routed back to the onboard USB ports.

Essentially moving the USB port over from the motherboard to the USB hub.

On the picture

, the two wires on the right-side is connected to the onboard chipset traces and the wires goes to the USB hub. The two other wires on the left-side comes from the USB hub and goes back to the USB connector on the right-side of the Eee PC.

Power is routed from one of the 5v points and through the switch board. Ground is connected to the nearest point.

Windows XP recognized the hubs and all the attached devices.

UsbHub

The rotating hubs I got is specified to provide 500 mA per port. The free port on each hub is the ports on the right-side of the Eee PC that I looped/hooked into.

UsbHub

UsbHub

All trademarks, graphics, images and videos used in this website are property of ModMyEee.com (unless otherwise specified), and may not be used without our consent. They are protected by national and international Copyright Laws. The information gathered on this website and in our Forums will not be sold, distributed or leased to third parties at any time. Marketing e-mails from ModMyEee can be ocasionally sent. If you wish to stop receiving those messages, simply use the "Contact" form and ask for an e-mail removal. Copyright(c) 2009 - ModMyEee.com