If you want to change hardware, you will need drivers, I think it's important and can be a real problem.

 

Hi Dalkor. Noted. We'll see what happens.

 

This will not be plug and play, you will need to mount the img and swap out the correct compiled driver for this gps chip. If we had source you could modify the necessary files and recompile the kernel, but without out source this will be difficult.

 

There is a linux version of the driver for Polstar modules here: PolstarThere are also some resources that I will be paging through: http://thedailyreviewer.com/hardware/view/adding-gps-receiver-to-an-embedded-system-110207978http://www.ngs.noaa.gov/gps-toolbox/exist.htmhttp://beaversource.oregonstate.edu/projects/44x200921/wiki/DesignSolutionsNone of these just jumps up and says "Here's your source code!", but there might be some hint/knowledge worth exploiting. This will be a fun project. I've never attempted anything like this before. We'll see where it goes. The Trimble/Lassen module is still in-transit, but I did get the Polstar unit. I'm going to have a look at it this weekend & see if there's anything that I can do with it. Source is going to be a problem, but I'm hoping to turn something up somewhere. Thanks for the input.EDIT: been reading a bit about the A81 circuitry here: http://code.google.com/p/a81linux/updates/list Since the PGM-111 operates handily from a serial interface, I may just solder it in to blank the RS-232 interface, and then run 5V power from the nearby USB port. This, and drivers...

 

Did you ever get any results? Does a Bluetooth GPS module work? EG. The Holux M1000There are some really small bluetooth GPS modules, smaller than the above which can fit on your keychain, the Qstarz BT-Q1300S is really small but pricey at $90. I keep a Holux M1000 in my backpack and use that as my GPS for my laptop, tablet and sometimes my phone because it is a lot better than the built in GPS esp. in cities where reception sucks. I will be getting my Wistech tablet in a few days and I will test out all of this. So I'll update this thread once it arrives.EDIT: Also there may be some hope the modules you ordered just all use standard NMEA signaling and don't require custom drivers.

 

After looking at the teardown images it looks like at least in those exemplars the GPS chip is soldered directly on. The antenna however is not. Did you find that to be the case for yours as well?It's looking more like a bluetooth GPS might be the way to go. If you're really adventurous I do think I saw 4 leads for a serial port debugging interface. I have no idea if it would be possible to repurpose it and I'm not going to try it, but you could potentially interface a serial port based GPS in through that and get a standard NMEA GPS running at 36,000 baud. I looked through my spare parts bin and found a nice ceramic antenna that has I hope the same connector that will be on my A81E when it arrives. If so I'm going to pop it in there and I'll tell you if that improves the GPS at all. I don't have my fingers crossed but it's worth a try.

 

Here's some info on the GPS. It is a Ublox GPS chip.u-blox: leading provider of GPS receiver modules and 2G/3G/GSM/UMTS modem modules, GPS receiver chips plus complete GPS/Wireless software, solutions and reference designsBy all accounts it's not the highest quality GPS supplier (SirfStar or MediaTek make the really sensitive quality ones). It might be possible to get better drivers or firmware from UBlox directly... perhaps at least fix the bug which has me appearing off the coast of Africa every time a new application requests a GPS fix.

 

a81linux - Project Hosting on Google Code[/url] Since the PGM-111 operates handily from a serial interface, I may just solder it in to blank the RS-232 interface, and then run 5V power from the nearby USB port. This, and drivers...

Hey, if the serial interface didn't work out, than you might want to just go with bluetooth. Bluetooth GPS Mouse unlimited - Android Apps and Tests - AndroidPITYou could solder a bluetooth GPS module onto the USB 5 volt leads and use Bluetooth GPS mouse to provision the bluetooth GPS data to all applications running in android.

 

Hi! Sorry that I haven't replied in a while. Looks like you're been pondering this quite a lot. I'm glad to see that someone else is thinking about this as well. Short version of my experimenting is that soldering the Polstar GPS in to the A81E was very easy. What I ended up doing was making the whole GPS module external, and plugging it up to the tablet via a 4-wire telephone plug. Per the plan stated above, I soldered wires for data to Serial pins 2 & 3, then 5v +/- to the nearby (and unused) USB 1 & 4. I then mounted the GPS in a RJ-11 phone modular jack casing - the little square thing that you sometimes see on the wall, or next to a desk. If the phone jack is not flush with the wall, it's one of these. The RJ-11 jack/plug offers 4 leads that you can connect to the power and data leads off the GPS module, as well as the corresponding pins on the PCB inside the A81E. You attach the GPS by simply plugging a short cable in to the jack casing. In theory, this is great. Only issue is that I couldn't get the drivers to work properly with Android. My skills with compiling kernels are not the best, so I have no idea if I was doing the right thing or not. So... I have a GPS module that I can connect (has power, and data connection), but it does not "talk" to my A81E. I wish that I knew more about this part of Linux/Android. Perhaps in time. Later, after I get home, and have access to the images, I will post pics of what I did. If nothing else, it's compact, cheap, and quite novel. I just wish it worked!I like the idea of trying bluetooth GPS. I will give that a try as well. I have a new iMX515, along with the A81E to try this on. We'll see what works. Most of the joy is in trying this stuff out, IMO. Thanks for your thoughts.

 

Great info, I would love to see pics of your work. Sounds pretty good. Unfortunately I also don't know much about adding in drivers in android. It's a real problem that we do not have sources to recompile the kernel. You can just try to load a kernel module in there that will interface properly with the GPS you've added. It might be easier to get your setup going with Windows CE, as with many Windows CE GPS applications you can specify a serial port and speed. From the software perspective jury rigging a bluetooth GPS into the case would be the easier solution, just get the full version of the Bluetooth GPS mouse application and it will provision GPS data to all your applications.Bluetooth GPS Mouse unlimited - Android Apps and Tests - AndroidPITBluetooth GPS DOES work, I've tested it with the above application. It works very well with my Holux M1000, but you do need to manually connect it on every reboot, at least with the Bluetooth mouse application (somewhat annoying). Improving Onboard GPS?http://www.v-sun.cc/asp_bin/downfile/20099278921134.pdfHere is a data sheet for the onboard GPS which Wits selected... if you have good soldering skills (it sounds like you do) you could purchase one of these and solder it on there. Unfortunately, it has some major problems such as always resetting your location to Lat 0 Lon 0. I am thinking about re-installing Windows CE again to see if this is an issue with the android drivers or the actual GPS hardware. It might be possible to replace the onboard GPS with a newer model with the same pinout, if it just uses a standard NMEA interface. Or perhaps update the firmware on the chip to improve performance. I'll keep you updated!!EDIT: Here's some more info from another poster about the onboard GPS.

A81linux[/URL] project page which lists the GPS module as an Ublox G5010-ST.Maybe UBlox don't manufacture parts themselves and just license designs to other vendors' date=' but it is strange that JRC don't list this part anywhere.If the GPS chip is actually labeled as JRC G591 I'd bet it's just some manufacturer selling ublox knockoffs labeled as non existent JRC parts.

Interestingly, if you compare the specifications for the Ublox chip and the "GPS G591" the Ublox chip is much better. So... if the GPS G591 really is some kind of knock off with the same pin-out the possibilities for a swap seems pretty good.

 

OK, here's some images of the external GPS rig. I thought I had teardown pics of the PCB, but apparently I didn't take them. Perhaps I will tear it open later so I can show the PCB. For now, though, here's the external module and how it's set up:

RE the other stuff: I wonder if a USB GPS Mouse would work without the app, and in place of the bluetooth mouse. If I can get signal via USB directly, that would be ideal. Here's what I'm looking at: Deluo USB GPS MouseIt's a bit of cash to throw at just suppositions, but hey... That's why I have all these different tablets. Worst case, I will just get a bluetooth GPS mouse, since there is already some documented success.

 

Just FYI, I was able to make bluetooth GPS work with my A81E. The actual BT device is a G-Sat BT-GPS-3720FA. I'm connecting to my MID via an app called "BlueGPS".

I've not taken any trips with it yet, but it pinpoints my location easily enough. I also have another key chain BT GPS receiver, a Teleprovodnik KGPS2000 that seems to work with my A81E reasonably well. So, there's some hope for those without, and those who have under-performing GPS units in their MIDs.

 

I have success with USB GPS receiver BU 353. WITS will work with any PL2303 based USB GPS dongle. How to make it work:
1. Check baud rate of receiver. It must be 9600. I switched mine from 4800 to 9600 with SIFR Demo utility.
2. Change GPS data port from /dev/ttyS2 to /dev/ttyS3 in /system/lib/libwitsgps.so with any HEX editor
3. Make symlink from /dev/ttyUSB0 to /dev/ttyS3

There are some issues with 3G modem + USB GPS module combunation, since they all make nodes in /dev/ttyUSB(X). So, it's important to check numbers in case you use both ;-)

 

Why go to the trouble of ripping the tablet apart when you can bluetooth a separate GPS reciever.

I use a Jentro Activepilot GPS Receiver connected via Bluetooth to my A81H+ tablet using the Bluetooth GPS Mouse Application which is a free download from MARKET but can be purchased for a very small fee.

 

Hi durden

I have the ACER aspire 4820T that comes with bluetooth inbuilt. I have the Microsoft bluetooth mouse 5000. I have always been using it with no problems. Suddenly it stopped working.

As usual, I thought I can just re-installing it by using the pairing function under the bluetooth panel "Add a device". Best part is the wizard just keeps going and never stops. My mouse is already in pairing mode.

Next check under devices/printers and believe it or not, it appears as indicated. However under the bluetooth control panel (Show Bluetooth devices), no mouse. In the devices & printers panel, the mouse shows up.

I cannot use the mouse or do a manual installation.

I have also tried to upgrade the drivers for the bluetooth and still not working. Tried the mouse with another computer and no problem. Can anybody advise how to do a reset of the bluetooth module or settings?

Short of a complete reinstallation of win 7 (which I hope to avoid just for one mouse), I have run out of ideas.

Hope somebody can render any insight as to how to resolve the issue.

Durden, did you contact Acer support about this? I tried to but they just blame the mouse and software? Any luck on your side?

Thanks for reading.