Eee PC Internal Upgrades

To install devices internally, more USB-connections are needed. I hooked into one of the regular USB-ports and routed the D+/D- signals from the southbridge/controller to a 4 port USB-hub. To make the port I hooked into work again, one of the 4 ports is connected back to the USB-port (Hub-to-USB-port and USB-port-to-HUB). This allows for total of 6 internal USB devices.

There are several points on the motherboard where power can be draw, for both 3.3v and 5v devices. Ground is universal and allows for short runs.

USB hub

I installed 2 hubs to get enough ports and load balancing the bandwidth. Having two storage devices on the same upstream connection is not a good idea speed-wise, therefore I put one on each hub (flash drive and card reader).

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

• Be able to use Mini-PCIe cards based on USB later.
• Disable the USB-ports in BIOS and disable all the new USB devices.
• Not having to deal with the webcam or wifi disabled in the BIOS affecting the USB hookup (unconfirmed if USB is also disabled).

More information about USB hubs over at Wikipedia.

Models

For the type of hub, I went for as small as I could find. The one I found had four rotating USB connections and one upstream connection sticking out from its side. Also a power-LED and external power connector.

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

• Korea rotating USB hub
• Synapsis flexible hub
• And just " USB 2.0 Mini Rotating Hub"

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.

Installation

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:

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

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

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.

Overview:

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

GPS with antenna

Wouldn't it be cool to have a Eee PC with a integrated GPS unit? Yes! I certainly thought so. Doing some research, I found a DIY kit on Ebay for a decent price. The bulk kit included a GPS unit, antenna with 3 meter cable and mmcx connector, USB cable, plastic case, and two screws. Suitable to be permanently installed in a boat or car.

The GPS board itself was quite big and I had to strip it down as much as I could. Removing the LEDS and two connectors was easy, getting the board shorter was a bit harder. The 3.6v standby battery could easily be connected off the board, and cutting the side of the board freed up some valuable dead space.

The antenna was the most critical part and had to be fitted outside the shielded Eee chassis. Before ordering the kit I was hoping it would fit in the display, and guess what, it just did by a small margin. The crystal on the underside had to be moved to the side of the main antenna body, and if all is good the RF characteristic won't suffer to much because of that.

To fit the antenna next to the display, I had to cut away 3 stubs holding the cables in place and a placeholder for the display unit. None of these stubs are voiding the integrity of the display, it all fits and holds together as stock.

I stripped the outer insulation of the RG-58 coaxial cable and replaced it with Kaptop electronic tape. That made it less rigid and easier to work.

Routing the webcam and speaker wires to make space was pretty easy, lots of slack. I fitted the coax cable first, then soldered the core and shielding to the antenna.

After some more re-adjustments and re-positioning the wires, it turned out quite good I think. The webcam wire placed between the locking mechanism and antenna is not squeezed as it might seem. The antenna unit is flush to the display and the front panel clicks into place perfectly.

The placement for the main unit needed to go through a few trails and errors before figuring out the only space large enough to house the unit was over the ethernet controller, next to the audio and amplifier chip.

It is a tight fit when closed, but there is still space lef over the unit. Though not much. It's powered by 5v.

Bluetooth

Somehow Asus decided to not include Bluetooth in the final Eee revision. Previous prototypes showed a clear Bluetooth icon on the keyboard, but all production machines lack the icon and stock Bluetooth support.

Bluetooth adapters have always been small and recently newer models is just the size of the USB connector. I decided to find a cheap no-name adapter and found a egg shaped one on Ebay.

Opening the adapter has to be one of the easiest I've done so far. The casing is just held together by a center piece and the circuit board in the middle. Luckly, the adapter was easy to run off 3.3v. I removed the LED to save another 20-30 mA.

After mounting the GPS antenna, the only place left to mount the adapter is in the bottom-left side of the display. All other places the Bluetooth antenna would be blocked or the reception degraded. The wires could be routed through the same dip in the motherboard as the fan wires.

As with the GPS, the adapter is flush to the display and will not protrude with the front panel in place.

Card reader

It would be great if I could have a internal storage space that I could replace easily to a higher capacity or take with me if I wanted to. In the expansion bay there is a gap between the memory socket and the bottom casing. It is normally blocked on one side with a piece of black foam.

Removing the foam allows for a SD card to just fit in-between. On the inside, there is space between the memory socket and the Wifi adapter for a small USB card reader. Trying both straight-angled and side-angled card readers, only the side-angled card reader fitted properly and even then it had to be stripped down.

Stripping the USB connector and cutting of the dead space on the end made the adapter smaller. Removing the unnecessary LED also conserves some precious batter power, 20-30 mA. The card reader uses a chip from the same vendor as the USB hub, Genesys Logic GL828.

Mounting the adapter at the right height was crucial. Because of the tight fit, the adapter had to have some margin to tilt and move.

The best way seem to pad the bottom of the adapter at the right height using doubled-sided adhesive foam-strips. When closing the case, the bottom of the chassis would press the adapter downwards and hold it at the appropriate height.

As this picture shows, the adapter will touch the Wifi adapter and have a small tilt towards the memory socket.

Power switch

• Integrated: Webcam, Wifi PCIe adapter, SD card reader, Sound card, Atheros eithernet, Atheros Mini-PCIe adapter
• USB hub: Bluetooth, SD card reader, GPS adapter, FM transmitter

Modem

The modem port on the Eee is stuffed with a piece of black foam and not used. The modem is not installed on any Eee machine but the internal connection points are still there. The modem card connected via a MDC v1.5 connection, and 12 pin header for the card and the 2 pin header to connect to the RJ-11 jack is still in place on all current 4G motherboards.

Asus is still providing the Windows driver for the Conexant 56K modem on their download site, look for Modem_XP.zip

The modem card can be found on various Dell, Acer, and Sony laptops. On Ebay the Conexant card can be found under these model numbers:

• Conexant 56K Modem RD02-D110
• M5804 (Dell part number)

Wifi

The wifi-card on the Eee is only 802.11b/g, not the latest draft-N. The card is can be easily changed by removing two screws and unmounting the card from the Mini-PCI Express socket.

After searching around I found a Intel 4965agn 802.11a/b/g/n Mini-PCIe card for a decent price.

Since 802.11n is MIMO (Multiple Input Multiple Output) it requires 3 antennas for optimal performance and range. I had a dead Nintendo Wii which happens to use the same antenna connectors for it's Broadcom wireless-card. The connector type on the Intel card is Hirose U.FL-R-SMT and on the antenna U.FL-LP-066.

Other Possible Internal Upgrades

• USB relay power switch
• New keyboard (non-taiwanese) [1]
• FM transmitter
• CPU/GPU/Chipset voltage mod
• Silicon Motion NAND flash replacement
• Modemport - Wifi antenna, additional ethernet port
• Modemport as a switch - remove to turn off, plug in to power
• Disable the fan to conserve power
• USB touch-screen overlay
• Copperplate with thermal tape better cooling

References

• Internal USB gadgets on miniPCIe connector
• tnkgrl USB research
• RFID Windows log-on
• Asus EEE News, Mods, and Hacks
• 802.11n Wifi Modification
• Modding Eee 701 with internal bluetooth / Engadget
• Keyboard light mod
• Eee PC USB Hub + Bluetooth + 4 GB flash - Chinese
• Eee PC USB Hub + Bluetooth - Chinese
• Modify generic 12v car adapter to supply 9.5v
• Eee + Hub + 2x 16 GB Corsair Voyager