Thread: GPS GPS GPS!
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Old 11-30-2007, 07:59 AM
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Quote:
Originally Posted by shadowmite View Post
Yep, you are correct, that's the pic the sprint 6800 at least has. And I believe you're also correct it's possible that it's a patch antenna. Hmm, I really can't say at this point, but what about the missing part (I believe a diode)? I think we'll have to wait and see if anything is activated by sprint here. But I will start to reverse the radio code and see if I can find anything that leads me to believe there is a gps mode to enable. With a patch here and there we can supercid the radio and be able to send any AT commands we want (including the gps fix request to test this).
It's going to take a bit more than enabling the gps in radio. I've looked into this, and I did a bit of research on how they enabled (or tried to) GPS on the hermes myself. The main issue is that from bootloader, we have no access to rtask, or prouter yet. I think spl-1.40 _might_ correct this, I've been looking to do some debugging in KITL myself, which is currently not enabled in spl-1.20.

Even with a rtask enabled, theres still considerable work you need to do with the ril in ce so you can talk to the gps (expose it to some com port). With the hermes, a lot of people spent a lot of time, and in the end they couldn't get an accurate (or usable) signal fix.

With that said, and the "promise" of gps and rev-A being available in Q1 2008, I would think that hacking the gps would be purely "educational" as by the time you got close to figuring out sprint would have probably released an official gps rom. Even if sprint decides to back out from releasing gps on the titan, they probably will release it on the touch, which has a rillayer thats actually completely compatible with the titan. Assuming that we enable gps in radio, we'd be in buisness.

About the missing antenna, they may have decided (sometime in production) that not putting it in wouldn't significantly affect performance to justify its cost: I'm sure you'd still be able to get some sort of signal from the ~1500MHz band off the 1900MHz CDMA antenna, and that may have been a last minute design decision. (note: I haven't looked at the pictures yet, but do you see any duplexer/diplexer/triplexer circutry to the radio antenna?) I doubt Sprint would have said GPS will be enabled if they knew it was permamently disabled in hardware, I also doubt that Sprint would have been so cheap as to not pay a few cents for a piece of copper that it would permamently disable any chance of hardware gps.

In short: I believe there will actually be an official sprint release. I think that although it'd be fun to figure out before sprint, chances are more than likely sprint will figure it out before us. I think that our efforts are better directed at something else (like getting video acceleration working!!!). Besides, without access to rtask in bootloader its unlikely you'd be able to get any control over the radio (or be able to debug the radio).
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