Android and GPS

So, I've been traveling way more frequently than I used to and I figured having the GPS on my Android devices could be handy.  However, I realized that my Acer Iconia Tab A500's GPS never actually worked.  Also, the MoveTab had GPS that worked really well and then suddenly stopped working.  If I remember, GPS never worked for my Samsung Galaxy Pocket either.  All of these nonfunctional stuff got me reading and investigating just how to use this equipment.  Read that after the jump!  Note that a lot of the focus of this article is on my poor Acer A500 and its horrible GPS.

My MoveTab's GPS

It didn't take long for me to come across an article that explains just what the GPS receivers in these Android devices are.  Android devices use what is referred to as AGPS where the 'A' means assisted.  This means that the GPS will also make use of Wi-Fi signals and Cellular signals to get a read of your positioning.  After I read this, I immediately realized that the Move Tablet had a SIM card on it when the GPS was functional.  When I tried to use the GPS now without the SIM, the GPS tracking was basically non-existent.  Slipping one back made GPS work once again which was great.

The Awful Acer Iconia Tab A500

I've been battling this one for far longer.  Since the A500 doesn't really have a cellular network capability, the GPS is already significantly hampered.  A lot of the solutions to fixing the GPS involved rooting the device which is something I'm not fond of doing.  Essentially, I found out that the GPS receiver used on the A500 is a BCM4751 Broadcom chip.  This uses a proprietary GPS almanac (lto.dat or Long Term Orbit data) and is nowhere in the A500.  With that data, the Broadcom chip can instantaneously find the GPS satellites but the file expires in about 7 days time. Well, this sucks.

I read somewhere that the GPS receiver needs a 'burn-in' so to speak.  The GPS needs training to find the satellites and get a fix on them.  At first, I was getting no satellite fixes no matter what I did.  Then, I realized I may have positioned myself rather poorly.  So the following paragraph discusses how I got GPS sorta working on my stock non-rooted tablet.

The app I got was the GPS Status & Toolbox.  It's a nice little app and has several handy tools for getting GPS going, if you know how to use it.  The steps I used to get this thing working:

1. Launch the app and recalibrate the compass.  My Acer tablet's compass in the app was going around in circles.  Once I calibrated the compass, it stabilized to where it perceived North was.
2. Download the assist data.  I'm not entirely sure if this works but it doesn't hurt to put it in.
3. Burn-in time!  First of all, find a place with a clear view of the sky with as little obstruction as possible.  Most advice tell people to put their devices outside the house but I put mine in the living room near the big windows.  I made sure that there was a clear view from the tablet to the sky.  I let my A500 sit there without going on sleep mode and letting the GPS toolbox do its job.

After a few hours, I came back pleased that the device had found 6 satellites and had fixed on a few of them.  That's not a high number, but at least it's somewhat working.  I noticed that the GPS reception is weak on this tablet, however.  So moving my tablet into my room completely killed my GPS signal.  I'm going to observe this a bit more, but I do know that location does really matter with this thing.  For those with unrooted A500, this is probably your only option to getting GPS working.  Hope it helps!