General Discussion about what mods / hacks to do with an extra GPS dongle - Asus Eee Pad Transformer Prime

Ok, i know theres a sticky for the GPS dongle but this isnt one of those "Wheres my dongle" or how to sign up threads so i thought it diserved its own thread. If you have questions about how to acquire a GPS dongle or want to say you got yours or whatever this is NOT the place to do it. See the sticky. kthxbie.
Still with me? Awesome! In having multiple primes i have recieved multiple GPS dongles. Since i rarely use one as it is, let alone them all at once i was wondering what sort of tweaks / hacks / mods have people tried (or wanted to try but were too afraid of screwing up their only dongle) that i might do on my extra one?
I already plan on doing a full teardown, taking highres macro pictures of the connector as well as unsoldering the shielding on the PCB and seeing whats underneath. Anything else you guys can think of?
Im not too worried about ruining the device if it means i can try something cool! Lets hear those ideas!
UPDATE: isolated the dock connector. Thus far with my tester these pins are grounded: (back view)
_ _ _ _ _ _ _ G _ G
G _ _ _ _ _ _ _ _ _ G
I know theres an official dock connector thread here: http://forum.xda-developers.com/showthread.php?t=1630300 but im not sure which pins according to that thread match what i have here.
UPDATE 2: removed dock connector, looks like only the bottom row goes to the dongle, not sure yet if any of the top row go anywhere inside the dongle or if it terminates at the connector. Will continue to test.
UPDATE 3: Ok, uploaded my work for tonight, traced a few of the connections just to see where everything is going. There WERE a couple that were coming out the top row, the two resisters on top, that MIGHT be the trigger to tell the prime its connected to an external device? who knows. anyways, its very late here, i will continue to test as i have time and as people show interest.
UDATE 5/5/2012
Ok, been doing some research and testing and whatnot, i have some very bad news. In order to attach any kind of connector to charge the tablet with the dongle attached it would mean soldering a wire to four of the pins on the connector on the TABLET SIDE of the pcb, UNDERNEATH the connector (the really fine pitch pins). Maybe i will have to take a picture to show what is needed.
Suffice to say chances of a mod that can be completed by most people out there is very low. I will continue to try to find a solution.
The red square shows which pins would need to solder the 15v+, the ground could be soldered to any of the grount points. (+5v to each of the three pins or +15v to all three)
Additionally, i have been doing some work on the pinout, trying to clean up the information we currently have. No offence to bjonston115 but his thread is confusing since every source has pins labled differently and there is info scattered everywhere. Bear with me as i try to sort the mess out and make something we can all use

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You are so lucky. Wish I had a spare. My main hope is to determine who makes the connectors (if possible), and what pins are used inside that connector, along with how it's mounted.
My desire, is to procure a connector, to add to the dongle shell, and the wiring, so I can permit the tablet to be charged while the dongle is in use.
When I drive 14 hrs to FL, my battery will run out, mid trip. So far, my only solution is to carry an external GPS to use while the TP charges.
Looking forward to your teardown.
Bob

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Images. Took as many pics as i could as i was removing bits n pieces. If you want a picture of a specific part let me know. Pictures uploading, give me a minute or two...

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I think a power mod should be straightforward. The dongle shell looks "thick" enough to accomodate a USB female Type A connector, mounted orthogonally. You'd want one with right-angle contacts similar to the one below, so you can let it "bottom out" against far side of the dongle shell. For aesthetics, I'd dremel the opening at the back side of the dongle rather than front, but this depends on your car mount.
The next step is to solder jumper wires from USB's power and ground pins to appropriate pins on 40-pin connector. Since USB adapter for TF101 is same for Prime/300, we can assume pin-out for USB functions is still same. Somebody already posted partial pin-out in another thread.
Soldering to the USB contact isn't a big deal, but to the finer-pitch 40-pin connector would take a bit of finesse.
Note: TF101/201/300 can charge with [email protected]
@pileot: Suggest taking a caliper and measure inner and outer thickness of dongle (ie w/ and w/o the shell thickness).
http://www.ebay.com/itm/1PCS-USB-sh...ale-socket-Connector-PCB-Socket-/260991770971

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unfortunately i dont have access to calipers, far as i can measure outside thickness is about 3/4 maybe slightly less, inside thickness is about 1/8 inches. sorry i cant be more accurate.
im assuming you want to throw a USB on the PCB? im not exactly sure how you want to connect that usb female connector, or what the purpose would be to do so.... Mind explaining just a little more?

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Mount: Use dremel to create a rectangular hole (12.5mm x 5.2mm) at the back (or front) of the dongle. Use a short-body USB connector w/ right-angle contact like the previous, and mount it orthogonally, eg perpendicular to dongle facing. I think the short-body one has a length of about 0.5" so it should flush-mount. But if not, having it sticking out a bit isn't a big deal.
Purpose: To charge tablet w/ either [email protected] or [email protected] I would go with the second, since USB car chargers for it are widely available (that's what the iPad uses).

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e.mote said:
Note: TF101/201/300 can charge with [email protected]
Click to expand...
Click to collapse
I know that the PC USB charge @~500ma takes forever and the TP has to be shut off, but what would the deal be with [email protected]
Would I be able to continue to use it as it charged, or would it need to be shut down too.
I'd probably use a USB 3 connector in place of the pictured USB 2
Thanks for the idea...I never thought of that....now all I got to do is to wait till I get my dongle.
Bob

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ahh! makes sense.... sure would be nice if we had a full connector port. Maybe i could make a trip to an electronic component store and pick up some USB connectors.
If you just want to use it for power then dont we just need any sort of connection to the charging ports and the outside of the dongle? It doesnt have to be USB it could be anything as long as you have a male and female connection

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pileot said:
unfortunately i dont have access to calipers, far as i can measure outside thickness is about 3/4 maybe slightly less, inside thickness is about 1/8 inches. sorry i cant be more accurate.
im assuming you want to throw a USB on the PCB? im not exactly sure how you want to connect that usb female connector, or what the purpose would be to do so.... Mind explaining just a little more?
Click to expand...
Click to collapse
There is a neat tool in Google Play called Smart Tools. Possibly you could get better measurements of the items you want to measure by using the tool, and laying the item right on the screen. I have it installed, and think it was a well done app.
Bob

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>I know that the PC USB charge @~500ma takes forever and the TP has to be shut off, but what would the deal be with [email protected]
No idea. That's something you can find out afterward. Having the mod in place won't hurt anything.
My guess is that it should be good enough to at least maintain battery level while on, which would be all that's needed in a car.
>It doesnt have to be USB it could be anything as long as you have a male and female connection.
You can use barrel power connector. But you'd have to make your own power cable, as opposed to using a standard USB cable to connect to the charger. Edit: On second thought, you can use a [email protected] car charger, then get a mating barrel connector.
http://google.com/search?q=12v+1.5a+car+adapter

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from what i understand if you have the tablet on and try to charge with 5v it wont even maintain the current battery level. The tablet charges with 15v or something... having a barrel connector would ensure you dont accidentally plug a prime charger into another USB device frying it.

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At that point if we could just get the barrel plug right to the power pins, fitting it in should be too hard....I am really interested iin this because I have 2 dongles coming tomorrow annd planned on hacking one....(I got two because one was RMA and they sent me a new one back 2 serials=2 Dongles)

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BSMan1011 said:
At that point if we could just get the barrel plug right to the power pins, fitting it in should be too hard....I am really interested iin this because I have 2 dongles coming tomorrow annd planned on hacking one....(I got two because one was RMA and they sent me a new one back 2 serials=2 Dongles)
Click to expand...
Click to collapse
See edited first post. Because the top row does not go to the back of the PCB and i believe thats where the power is, it would be hard to throw a charging circut in there. I am still working on locating where all the pins in this thing go but it is very tiny, even with my finest nodes to test these circuts its very delicate work.
In the mean time, i will upload what i do have before i go to sleep tonight (maybe in another hour or so) so stay tuned!

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Okay I will try and keep updated... if we could get a charging circiut in maybe a true car mount might be a project... at least for me, I already have a tablet window mount and with some changes I could affix a modified dongle at the bottom and just slide prime in for GPS + charging (again if we can get it to work)... I get mine today and disassembly will soon follow so I will post anything else I can to help progress

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pileot said:
UDATE 5/5/2012
Ok, been doing some research and testing and whatnot, i have some very bad news. In order to attach any kind of connector to charge the tablet with the dongle attached it would mean soldering a wire to four of the pins on the connector on the TABLET SIDE of the pcb, UNDERNEATH the connector (the really fine pitch pins). Maybe i will have to take a picture to show what is needed.
Suffice to say chances of a mod that can be completed by most people out there is very low. I will continue to try to find a solution.
The red square shows which pins would need to solder the 15v+, the ground could be soldered to any of the grount points. (+5v to each of the three pins or +15v to all three)
)
Click to expand...
Click to collapse
Okay first off...have we all decided to stay low until we progress, i don't want this thread to die so soon...secondly...though I am sure you have done you research I still must ask, Are you sure? if we can provide any charge to the prime it will at least help a bit...also does anyone one else have other ideas other than charging?...
one idea I literally just thought of so it is not very thought out is, what if we remove the dongle case( as we have done) and integrate it into case.... we will need one of the 40-pin cables to wire onto it but maybe it could fit into some cases.
I will continue to try to think of more uses and mods and will update, meanwhile I hope that we can get some more input

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Hmm, you've made quite a bit of progress there. I really wish I wasn't lazy haha, I need to learn to really work with electrical stuff.
So, then the dongle uses some of the pins that would be used for power from the dock? If the dock can pass power without changing the Prime, I should think the dongle could somehow. I mean, only certain pins are used for data right, so the dock and dongle should use the same ones?

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Ok, firstly. Yes, im sure. Im sure of the pin placement and based on the best available information scattered around the internet, i know which pins the charger uses and i know where they are located on the dongle. I also know there is very little access to them (as seen in the pictures in OP)
as to integrating the dongle INSIDE the prime casing you would, essentially, be succoming to the same problem the internal antennas have: Metal blocking the signal. Sure its a more powerfull antenna however its encased in PLASTIC not metal, the signal it recieves is a lot stronger and there is less EMI caused by the metalic back plate. Short: Yes you can, no you dont want to.
Finally, the pins the prime uses to draw power are different than the pins the charger uses to supply power. Think one lane dirt road vs a 6 lane highway. On the highway you have dedicated lanes for traffic going in different directions. this is similar to how the prime dock connector works, the prime can turn off power to different connections depending if there is something plugged in reducing the chance of a short, spark, or power drain.
Hopefully this addressed your concerns, maybe when i have apropriate tools handy and a bit of time i may try soldering a connection to the dock connector and see how it functions but as you can see its REALLY tight. I will do my best, no promises.
I also plan, in the near future, to locate more of the data pins, see whats going on, maybe we can make a USB adapter for the dongle and use it in other devices as well! who knows, im thinking it just uses a standard USB interface but it will take more digging.

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Subscribed as I see no need for the dongle unless you have enough power.

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Though I was pretty sure you were sure I just wanted to ask.... but you did misinterpret my idea, I do not mean the Prime's casing but rather integrating the gps into a case which holds the prime...This is not to say that the gps is big or in the way but just an idea i had to help people with cases and a use for the gps, but since the usb uses different pins that looks unlikely as well i guess...well I will stay updated and if I learn anything I will post.

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I would be more interested in adding a power jack of some sort to the dongle. So you can charge while using navigation. I already can not use my dock while plugged into the dongle. We need power!