EeeTop – Part C

Posted 2009.05.28 16.03 in Pointless Blather by Stephanie

So, I got the graphics working right by using Ubuntu 9.04. I had increased the RAM and hard drive, and was looking to install Bluetooth. By now I’m getting bored of this story, so I’ll try and make this short.

I was thinking about tapping into one of the two unused ports on the GL850 USB hub chip. This is a 48-pin LQFP package, with 12 pins per side, and a pin-spacing of 1/2mm from pin to pin, with a gap of 1/5mm between pins. I have soldered directly to chips with pin-spacing this tight before, but it’s very, very difficult. And in this case, the risk of failure is losing the webcam, the SD card reader, and possibly wrecking the whole motherboard.

So I mulled it over for 2 days before it hit me – instead of tapping one of the unused ports on the GL850, just grab one of the existing USB ports. With 6 ports, there’s no way I’d use them all, or even half of them. I could just tap one and wire it internally rather than externally!

bt_cardOnce making that decision, the rest of the mod was fairly easy. I had a D-Link bluetooth USB dongle, which I cracked open and freed from its plastic shell, then desoldered and removed the USB connector. I soldered my wires directly to the circuit board, then wrapped it in electrical tape (to prevent short circuits) and finally hot-glued it to the top of the EeeTop’s internal screen shield. I positioned the bluetooth dongle so that its LEDs were facing forward and the LEDs (and the bluetooth antenna) were clear of the EeeTop’s internal metal shielding.

bt_wiresI ran the D+, D-, and Ground lines down to one of the USB ports (the one next to the power plug) and soldered them on. The EeeTop’s USB ports are powered even if the EeeTop is off, which I think is a bit extreme. I didn’t need the dongle to be powered if the EeeTop was off, so I found a 5vdc source that was switched, and soldered the Bluetooth dongle’s Vcc line to that point.

bt_led

 
 

Finally, I drilled a small hole in the front of the EeeTop’s screen bezel, then filled it with a translucent plastic, so that the bluetooth LEDs would be visible. This way when there is bluetooth activity, the LEDs can be observed flickering. Totally useless and unecessary, but I am a sucker for blinken-flashens.

 

usb_plug
One last thing I did, was to cover over the USB port before sealing up the EeeTop, so that there wouldn’t be a risk of accidentally plugging anything in there now that the port was tied to the internal Bluetooth port.

The EeeTop has a lot of empty internal space, so if someone wanted to add a bunch of internal USB devices, it would be trivial to add an internal USB hub and then add devices to the hub. While I think it is a frustrating waste that the onboard GL850 has two ports unused and unusable, it is very easy to tap one of the other USB ports and redirect that for internal use.

At this point, my EeeTop is all but finished. The only remaining aggravation was that the ACPI functions didn’t, well, function. Digging into the code, I found that other Eee systems used /sys/devices/LNXSYSTM:00/device:00/ASUS010:00 for where their ACPI functions came from, but the EeeTop used /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:03/ATK0110:00 as the ACPI hardware source. I fiddled around with this a whole bunch, but was unable to make it produce anything other than Epic:Failures. Finally though, reading a changelog for one of the kernel 2.6.30 release candidates, I saw that the Asus ATK0110 ACPI thingamajig had been picked up and would be supported in the next linux kernel. So when that is ready, I’ll give it a shot.

For now, my EeeTop is up and running as my home server, and is working just fine.

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