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Edits: Pictures have now been added where appropriate (thanks to gospeed.racer for the assist there). Also, I've now added a USB hub, BT module, and 8gb flash drive, plus an open USB socket for a future device... read on to later posts
I wanted an internal USB flash drive, but did not want to open up the unit (other than the memory access door) or solder anything to the board. I wanted the mod to be 100% reversable, with no traces left at all, thus preserving the warranty. A tall order perhaps? Not as it turns out.
I was looking at my eee the other day (a new white 4g, without a flash connector in the memory bay), and pondered the 3 usb ports. Too bad, I said to no one but me, that one of those couldn't somehow be accessed from the memory door area; after all, I can't imagine using all 3 of them at once, ever. Looking at the ports on the right side, I noticed the two little metal tabs in the bottom of each port; through the small gap around each tab, I could see light coming through the vent under the wlan card. I wondered further whether four small wires could pass through the gaps around those little tabs, under the wlan card (or over it, if you've turned your eee upside down by now), and into the open flash bay. I tested with a bit of solid wire, and found I could easily guide a wire into the flash bay; there's nothing obstructing the path.
Theory proven, on to implementation. Keeping the theme of making no mod at all to the eeepc, I needed a usb 'plug' that would fit entirely within the socket, and allow the four wires to escape through the two tabs. I observed that the size and spacing of the four contacts in a usb socket is just about exactly the same as on an old ISA bus card, or also the same as the card-edge connector used on old-school 5.25" floppy drives. Rooting around in a box of old junk, I came up with a once common 34-pin socket to male card-edge adapter (used once upon a time to install 3.5" floppy drives in older PC's that had only card-edge floppy connectors). Trusty dremel in hand, I sliced off 4 contact's worth of the card-edge connector. 
(after-the-fact photo of the donor adapter)
A bit of filing, and it fit nicely in the usb port and the contacts lined up PERFECTLY. It was a little loose vertically though, but there's still wire and solder to be added to each contact.
Grabbing 4 lengths 30awg wire-wrap wire, I soldered each one along the length of each of the four contacts, and then filed the resulting solder beads down flat to make nice contact with the contacts in the USB port. Another test fit, now it's nice and snug.
On to the hardest part: guiding the wires inside the eee to the flash bay. Using a tiny screwdriver, I carefully bent both tabs down into the usb port, opening up the path. I found all four wires had to be guided through at once. A little trial and error, and a few swear words later, all four wires appeared in the flash bay. Now, I GENTLY bent the two tabs back in place, taking care that each wire had a place on either side of each tab. CAUTION must be excercised here - it wouldn't take much to strip away the thin insulation, and of course those metal tabs are grounded!. Finally I gently slid the edge connector into the usb port, carefully guiding the wires the last few millimeters into the chassis. (oh, all this was done with the ac adapter disconnected and the battery out too)
more detail:http://picasaweb.google.com/johnsonx42/ … 5300414530
At this point, I debated soldering directly to a flash-drive's PCB, but I decided I'd rather have a real usb port in there - that way I can easily swap devices, and preserve their warranties as well. I cut up one of those little 6" usb extensions that come with some small usb devices. It was a little big, but I forged ahead. I used the continuity test mode on my multimeter to double and triple check that I was soldering the right wires together as I went. I used small heat-shrink tubing to insulate each solder connection.
http://picasaweb.google.com/johnsonx42/ … 4398161026
After a quick boot up test with the usb port dangling out of the flash bay, I inserted a small 8GB flash drive, wrapped the works with a thin layer of padding to insulate the bare metal usb port and keep it all from rattling around, tucked it all in and closed it up. By default the eee wants to boot from the usb flash drive, but a quick trip into the BIOS setup tidied that up (which is not to say that first 'operating system missing' message didn't make my heart skip a beat!).
http://picasaweb.google.com/johnsonx42/ … 5937768594
In the next day or two, I'll fashion a plastic cover for the now occupied USB port just to keep everything looking neat (though you have to look close to notice there's anything going on there).
Later on I may get rid of the single usb socket, and instead solder the wires to a tiny USB hub pcb as described in other mods in this forum - there's room for two small usb devices in that flash bay, though they might have to be de-cased.
Once I started using the flash drive, I found Windows treats it as removeable media; disk management won't touch the drive, and some programs (Quickbooks Pro 2005) refuse to install there. Solution here: http://forum.eeeuser.com/viewtopic.php?id=26956
I hope someone will find this useful.
x
p.s. yes, yes, I know, a 'modder' who doesn't want to void his warranty isn't even a real man.
Last edited by johnsonx42 (2008-05-13 2:32:25 pm)
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I'd be real interested to see some pictures of your installation!
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In doing some more research related to my mod, I've discovered several things that may be worth noting.
1) I'm not the first to route one of the external USB ports back inside of the eee (no surprise). However, as far as I can see I'm the first to do it completely flush, with no external wires. Chewy did it with an external dongle, routing the wire back in through the modem port.
2) Apparently the external USB ports do have over-current protection, so perhaps the mobo would survive if one of the lines got shorted out.
3) It did cross my mind to use the lone port on the left side, but the fan is over there, and my brief attempt to guide a test wire in on that side encountered solid resistance at every spot. As to which port on the right side, I used the back one as it looked like the straighter shot into the flash bay; but the front one should be just as doable. At least this way I have one port on each side available.
4) there may be an issue with 30awg wire carrying enough current for more than one flash drive. Someone appears to have burned through the insuation on 30awg wire running a bluetooth dongle, which does apparently pull a fair amount of current for a usb device. Honestly I don't know what the current capacity of such wire is, or whether said burn-through was truly caused by normal usb current levels or some other problem. It will be something to think about and research if I later decide to add a hub and a second usb device.
edit: http://www.powerstream.com/Wire_Size.htm says the conservative ampacity for 30awg wire, for our purposes, is 860ma. This suggests that solid 30awg wire will be fine for any single internal USB device, and really should be of little concern for a hub and two low-current devices. However, if I do decide to install a hub and a second usb device, I will measure the total current draw before I finalize the install just to be on the safe side.
5) there are suggestions that the D+ and D- lines should be twisted together to avoid interference (differential signalling). I don't think it will make much difference on such a short run (3 inches), and my flash drive is working fine, but i suppose if i ever have to re-work this mod I will make some effort to twist the data lines. The way I did it the two data lines enter the eee separately, through opposite 'tabs' in the port housing, but they probably could be twisted a few times from the exposed ends in the flash bay.
6) the solution to my problem of the usb flash drive being treated as removable is apparently pretty well known, but I posted about it before discovering that. I guess I can say I've added to the chance that someone else's search for it will yield results.
Pictures: I will see about posting a pic or two. I haven't posted photos in a forum like this, what's the simplest way to do it?
Last edited by johnsonx42 (2008-05-06 8:31:23 pm)
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i too would like to see some pics.
i suggest uploading your pics to an image hosting site like flickr or imageshack to link them here.
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First off, **** nice!
Second off, this has got me thinking..... couldnt it be possible to take an old pci card or something with matching pins to the pcie slot (for those of us that have it) and cut the contacts down, and block out all the pins that dont go in as part of the usb connection? we could then solder onto those contacts a very small hub and make us a full hub kit that wouldnt compromise the eee at all.....
here is the pinout for the mini pcie slot.... someone work some magic:
http://www.interfacebus.com/Mini_PCI_Express_Bus.html
Is this too far fetched? It seems within the realm of possibility to me.....
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Thank you for the compliment on my work. On to your idea, which is good, but...
First, all current eee's being shipped don't have the flash connector installed on the second 'mini-pcie' slot, unless it's actually being used (8g, 900). Second, it isn't a mini-pcie slot at all, rather it's a proprietary pinout that includes a full ide interface, sata, usb. Some of the pins are in the same place as mini-pcie, like the usb pins (i think) (the pinout is known, so that in itself doesn't void your idea). Third, any existing pci or pci-e card you might think to cut up would be too thick to insert into the little connector, and wouldn't have contacts in the right places anyway.
edit:Thinking more about this, perhaps a cut-up ddr or ddr-2 memory module would work, maybe an SO-DiMM? I don't know, as my eee doesn't have the slot anyway. I think it would be the right thickness (1mm) though.
Someone has already gone through quite a bit of work on this idea, even going so far as having prototype boards made. But I think it was ultimately somewhat fruitless as the prototypes were too thick to actually use (thinner boards were too expensive), and none of the current shipping eee's have the slot connector installed anyway so the only market for such a device would be early adopters who have the slot, want a mod, and haven't already done something else.
Sorry to dash your hopes (edit: perhaps less dashed than I thought).
x
edit: well it looks like that project is much more recent than i thought, and still a going concern. http://forum.eeeuser.com/viewtopic.php?id=19835. Look for posts from RoamingStudio - on page 6 he's got photos of his prototype boards, and mentions that there will be a 1mm production run of some sort. Looks like he's got two boards - one just usb, one with a CF socket and a usb header.
Last edited by johnsonx42 (2008-05-06 11:21:36 am)
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Wait, so let me get this right..... If i were to go pick up... say.... a wifi n mini pcie card and tried to put it in that slot it wouldnt work?
Edit:
Found the pinout compiled in that thread.... just read all the way through it..... That is exactly what i had in mind johnsonx42.
I'm not as hardcore as roaming seems to be, so i'd settle for a mini pcie to usb adapter. Solderless internal (and removable!) usb hub appeals to me on so many levels...... And it seems like we might be very close to making this happen........ Something still isnt sitting right with me though..... it seems like we are missing something... like there is another way to go about this..... let me think about it for a while.
Last edited by jair2k4 (2008-05-06 12:37:08 pm)
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jair2k4 wrote:
Wait, so let me get this right..... If i were to go pick up... say.... a wifi n mini pcie card and tried to put it in that slot it wouldnt work?
That is my understanding. That is why, if you look at the board itself, the slot is labelled 'Flashcon' or something like that instead of 'MiniPCIe'. Some MiniCards just use the USB part of the interface which might work because those pins are still in the same spot, but most all of the other pins ASUS has used for something else.
The internal slot holding the factory wifi card is a real Mini-PCIe slot, so that's where your example wifi-n card would work. But then you need more antennas than are provided in the Eee... i dunno, would a wifi-n card work ok with only two antennas connected?
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Is there any chance a bluetooth receiver would work? I dont think it would draw more than 860ma, but do not have a multimeter to measure it. I would like to allow me EEE to connect to a BT GPS without a dongle. How would I go about measuring the current, simply put the meter leads in series with the power pins on the USB port?
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I am currently working on putting in a hub and bluetooth receiver (still without opening my EeePC, of course). It looks like I'll be able stack my hub, flash drive and bt dongle in one half of the flash bay, and still have room in the other half of the bay for a future THIRD usb device! Yes, I've swapped out my long flash drive shown in the pics for a much smaller (and faster) Lexar Firefly 8Gb drive ($35 on sale at Fry's). Speaking of Fry's, I got a bt dongle AND a hub for $10 (Vakoss TC-B241-US, Fry's p/n 4700349). The hub isn't what I would have chosen alone, but it was effectively free because when I found it I already had a $10 bt dongle in my cart. Desoldering the ports and cutting the board down hasn't been easy, but it's more relaxing doing it on something that was free in the first place.
Additional research has led me to conclude that this whole issue of using 30awg wire for USB power is simply a non-issue, and that the person who claims to have had a problem with it simply had something else wrong (kajer was it?). Someone else has run some tests, and managed to pull 4.7 AMPS at 12v through 12" of 30awg wire without issue (that's the most his test setup could manage). So we can see that even the 860ma figure is a very conservative number.
As to how to test current draw, yes, what you described is how to do it. As I wire up my hub and usb devices, I will arrange to test power draw and will post results here.
x
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Sounds like you've been busy! I did an alpha test tonight and found that I was unable to get the data pins connected with my 26AWG wire, however the power pins were fine. I had some 26 wire laying around and figured Id give it a shot.
I have located some Kapton 30AWG wire at a store nearby that Ill have to pick up soon. Is this the same type of stuff you are using?
Do you have any tips/suggestions as to how to make the USB board? Soldering is fairy easy, however getting everything to line up is near impossible.
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Current draw Measurements:
USB Hub Alone: 108ma
USB Hub w/ BT Dongle: 136ma
USB Hub w/ 8GB Flash Drive: ~200ma (had to switch meter to a less accurate mode for this measurement)
That implies the BT Dongle uses 24ma (idle), and the flash drive uses 90ma (idle), and that my hub/bt/flash combo will use 224ma (I can't actually test the entire combo together at this point, as I've removed all but one of the USB port sockets from the hub). While 224ma isn't much in the grand scheme of things, that's got to take a few minutes off my battery life.
A back-of-an-envelope calculation suggests my 7.4v 5200mah battery has 38480mwh of power. Assuming a 3 hour battery life in stock form, that suggests my eee draws ~12800mw of power on average. At 5v, the 224ma draw of my add-ons totals 1120mw, which works out to a 8.75% increase in power draw, and thus a corresponding decrease in battery life of ~15 minutes. (this all assumes the eee's voltage regulators are 100% efficient, which they aren't!)
Looked at another way, that 8.75% increased power draw will erase half of the ~18% gain in battery power I got by ensuring my eee came with the bigger battery. For the most part, that's the only reason I paid $50 extra for the non-surf, and that's why I have white instead of the black I preffered: based on their published spec's for the different models, the store would only guarantee that the white one would have the bigger battery. On the other hand, if I consider these mods mandatory then that just escalates the value of the bigger battery.
What's distressing here is that the hub by itself is taking nearly half of the added power, thus accounting for about 6-7 minutes of the lost battery life. I only need the hub becuase I don't want to solder to the eee's board, thus I have to make do with the one USB port I brought in at the start of all this. But right there in the flash bay, there are solder points for another USB port (pins 36 and 38 of FLASH_CON). It even looks like I could solder to them through the ram door opening, still no need for a full disassembly.
Now, if I could just think up a must-have use for the third internal USB port I'll gain in doing all this, I would then need the hub anyway, and could stop crying about the 7 minutes of lost battery life for the hub.
For those wondering exactly why I'm so hesitant to solder directly to my eee's board, it's not so much that I'm worried I'll brick it directly, but rather that at some later point something will go wrong with it that would be covered by the warranty, and even after I unsolder everything there will be enough tell-tale signs of my mods that ASUS will void my warranty.
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@KAS I'm using 30awg wire-wrapping wire (solid). I suspect that it's quite similar to what you've found.
Kas wrote:
Do you have any tips/suggestions as to how to make the USB board? Soldering is fairy easy, however getting everything to line up is near impossible.
Not sure what you mean. Which USB board?
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The USB board made out of the ISA bus. I am having a very hard time getting it cut to the right size with all of the wires lining up.
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Kas wrote:
The USB board made out of the ISA bus. I am having a very hard time getting it cut to the right size with all of the wires lining up.
Oh, THAT usb board. Since you mentioned 26 gauge wire, I assumed you weren't doing that part of my mod - only 30 gauge will fit in through the little tabs in the USB port.
Edit: I just dug up an ISA card to re-check my assertion that it would work, and the contacts do have the same spacing as the floppy adapter I used. The board thickness is also the same.
You just need to cut a section with 4 intact contacts, and leave it wide enough to completely fill the USB socket (thus it can't wiggle laterally and short something out). On my floppy adapter, I sliced down the fifth contact from the edge, which left 4 intact contacts and close to the correct spacing on either edge. I filed a good bit on each side to get it to fit nice.
Edit: observe particularly that once cut and filed to size, that the division between the center two contacts (D+ and D-) is precisely in the center of the board. There's not much space between those two contacts in the socket, so you don't want to be off center.
Edit: I do also note that the contacts in a USB connector are not completely equidistant from each other. The center contacts are closer to each other than they are to the outer (power) contacts, but not by much. It doesn't matter for this project, and my comment above covers careful centering.
If I'm feeling ambitious tonight, I might whip up another card-edge-connector-usb-plug-thingy and take some photos (I don't want to remove my installed one for photos - it's happy where it is!). A picture's worth a thousand words as they say...
Last edited by johnsonx42 (2008-05-09 2:29:31 pm)
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A picture would indeed help, but I think I have a handle on how to make it. Thanks for the tips, they touched on why my alpha test last night did not work.
I managed to pick up a spool of 30 gauge, however the insulation is PVC (I believe). Is there any concern about potential lack of heat capacity as Kapton wrap is likely more durable.
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I don't think heat will be a concern with any insulation type. The wire is only being routed through open areas of the chassis, heated by ambient temps to 60C or so at most... not really very hot at all.
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johnsonx42 wrote:
I don't think heat will be a concern with any insulation type. The wire is only being routed through open areas of the chassis, heated by ambient temps to 60C or so at most... not really very hot at all.
I was more so concerned that should the current passing through the wire get to high, it would heat up, melt, and make a mess inside the EEE.
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I spent around three hours tonight trying to get the USB/ISA board to fit. I am using the correct 30AWG wire however simply cannot get things to line up. When I am checking my connections I am measuring voltage across pins 1 and 4, looking for 5v, and across pins 2 and 3(data), looking for 1-2v. Normally what happens is pins 1,3, and 4 are connected while 2 is open. I add more solder to 2, and then 3 becomes disconnected. Now that I think about it, could my measuring system be incorrect?
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@KAS:
After soldering each wire along the entire length of each contact (don't just solder the wire to the end of the contact), did you then use a file to flatten out the solder beads? You want to get a nice even surface for the usb contacts, so that none are higher than the others.
I don't know whether the way you're measuring is correct. Obviously you should be getting +5v across 1 and 4, but I don't know what you're supposed to get across D+ and D-. Maybe measuring D+ and D- to ground would be a better method? Honestly I didn't measure mine, I just trusted that it would work.
I've used up all my time for tonight (see the next post), so I didn't get a chance to make another card-edge-usb-plug-thingy and take photos. I'll try to do so sometime this weekend; when I do, I'll edit this post and add the photos.
Regarding the wire getting hot from too much current, don't worry. The guy who pulled 4 amps through 30awg wire noted very little temperature increase. Remember also that the external USB ports we're using have over-current protection; you won't get anywhere near dangerous current levels before the protection circuit turns off the fun.
Last edited by johnsonx42 (2008-05-10 5:55:35 am)
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USB Hub, BT Module, 8GB Flash and spare USB socket mod complete!
Read post 10 for details about the hub and bt module I used.
Link to Picasa album: http://picasaweb.google.com/johnsonx42/HubBTMod (same photos as posted here, but bigger, zoomable, captions I may neglect to repeat here)
The completed hub assembly with 8gb Lexar Firefly (decased, but otherwise completely intact), BT module (lost it's usb plug), and the spare USB socket (the heavy usb cable is just there for a quick test on my desktop PC before final installation:
Note all the missing components. After careful inspection and testing, I lopped off 1/4" from both ends of the board, and cut off all the capacitors (not the SM ones of course, though I did bust one of them off on accident too; doesn't seem to have hurt anything). The power diode was standing tall as well, so I laid it down.
It will be installed with this side down against the eee's board, so this side gets a layer of electrical tape before installation.
Installed in the flash bay:
Electrical tape holds the flash drive in place, and holds the USB port next to the board. The BT module is tucked under the edge of the plastic casing, but isn't otherwise secured - it's got nowhere to go though.
Whatever shall I stick in that USB port? Nothing for now, but it's nice to have it there!
Oh, I was worried about the range of the BT module inside the shielded bay. But I just hot-sync'd my smartphone from 10 feet away, good enough for me!
Maybe it's all not that amazing compared to the folks with a touch screen, gps, extra card readers, tv tuner, wifi-n, etc., but I do still have my factory warranty! Anything goes wrong with it all I do is pull out the boards, cut those four blue wires, and pull them out through the usb port... no hint I ever did anything to it.
edit:A Note about the black vinyl electrical tape: I did have some concern about using that black vinyl electrical tape, as it tends to get sticky and gooey with time and heat. The very old roll of electrical tape I had on hand had already become rather gooey, so I wasn't going to use it. I went over to Fry's to see about something newer and better, but all I found was more of the black vinyl tape (and pretty colors too, at thrice the price). However, the label said it was good up to 80C, which is a good 20C hotter than an Eee ever gets in that area. So I decided to go ahead and use it since nothing else was readily available. Now, admittedly, being usable up to 80C doesn't per se mean it doesn't start to get oozey and gooey at much lower temps, so I've resolved to check the tape periodically to see if it shows signs of doing what we all expect that sort of tape to do. Since this is all just inside my ram bay, it's easy to check and easy to replace if need be.
No one should infer that because I used it then that's what they should use! The 'kapton tape' most other modders around here talk about is undoubtably a far wiser choice.
Last edited by johnsonx42 (2008-05-14 2:24:59 am)
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And this is still all done without opening the case? I'd say it's just as good as fitting a touchscreen. Kudos, consider me inspired.
Right, off to the loft when I get home n dig around in my bits box for supplies, and chat Mrs B into letting me part cash for a soldering iron...
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brilliant mod. I can see a small market here for some sort of kit.
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Yep, still haven't opened the chassis. Save for all the posted photos here on eeeuser.com, I have no idea what the inside of an eee looks like!
Thanks for the compliments bascule and britman.
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Got mine up and running! I accidentally smashed my female USB port so I ended up soldering the wires directly to a USB bluetooth dongle. While I cannot easily change devices, I dont see myself doing so in the near future. Looks like I will have to get the USB hub to continue my hacking. Where did you buy the hub from? Thanks!
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