GPS GPS GPS!

[Murph24]

Good points Luv2Chill, I had some of the same questions. I think we should keep in mind that while the Trinty does have similar GPSOne technology, we are dealing with a new CDMA chipset, not the older GSM chipset of the Trinity (MSM6275). Based on the Qualcomm spec sheets there does appear to be some differences in the architecture between the two. Its interesting to note that on the MSM7500 (Mogul) spec sheet they seem to show the GPS and CDMA signals multiplexed onto the same antenna on the recevier side of the radio. They also say on their data sheets "Alternate GPS antenna configurations are available".

Mogul here:
www-cdmatech-com/download_library/pdf/diagram_msm7500_cs.pdf
(mods a little help with the links please )

Trinity here:
www-cdmatech-com/download_library/pdf/diagram_msm6275_cs.pdf

Another link about the RFR6500 radio receiver side chip:
www-cdmatech-com/news/releases/2003/031112_rfr6500.jsp
"Integrated GPS receiver allowing for simultaneous GPS operations with CDMA2000"


I also find it interesting that many of Sprint Telenav phones require BT GPS when they should be capable of AGPS based location (PPC 6700). Hopefully they plan on giving us some sort of limited access to the integrated GPS for Telenav purposes on the Mogul in order to spare us the BT GPS puck. IF thats the case maybe there is hope that it can be exploited with hacks.

SO, in a nutshell, I don't think we should have a separate GPS antenna in the Mogul because the GPS receiver uses the cell antenna....

Who knows....I'm probably blowing smoke out my a$$, but it is interesting.

Any gurus have an any thoughts on this???

[fesstech]

I agree with Murph24. I just read those data sheets as well. The MSM7500 has fully integrated GPSone. And can triplex the antenna. A-GPS is defined by Qualcomm as better than stand alone mode (a broader location fixing capability), however the MSM7500 can function as A-GPS, standalone or a hybrid mode. Qualcomm also states that no extra hardware is required to use the gps function in its chip, such as RF modules.

As an electrical engineering grad student, i feel access to GPS most likely disabled through coding, not the lack of hardware. There may be a small chance there is a solder pad that can at as a full access switch since the data sheet since it shows a toggle switch going to the local GPS schematic. I will try to contact qualcomm engineers to learn more.

i am optimistic.

unfortunately i dont have a Mogul to crack open and inspect.

[Murph24]

Fesstech, I agree that the "switch" is probably just turned off in the ROM. So it looks like we might have our antenna after all. Although there is still a chance they intentionally crippled it at the hardware level. Hopefully the ROM coding required to access the GPSone on the Trinity is similar to what we need on the Mogul. Shadowmite????

[korndogg]

Has anybody downloaded the ROM from HTC? It does say on the site that the ROM does enable standalone GPS. The website is http://www.europe.htc.com/support/so.../htcp3600.html. I don't have one, otherwise I would download and flash with this ROM. I really want to know because I want to buy a 6800, but I don't have Sprint service out here so I would have to pay full price and get Alltel to hook it up for me.

[flipside]

Your link is broken, but there is no ROM out for the mogul. Using anything else you risk bricking your phone.

The "AGPS" in the mogul is very accurate. I've mentioned this in other threads, but you can sign up for a 2 week free trial of the "sprint family locater" at sfl.sprint.com. I signed up and it had me pegged to my exact street location. My wife's treo 650 has "AGPS" as well, and even though her phone was on the desk next to my mogul, it had her pegged more then 2 miles away.

Everyone here should sign up for the free trial and post how accurate it is. Something is up here. There's got to be a way to mess with this thing.

[fesstech]

Murph24, I think the only way to cripple the integrated GPSone at the hardware level is by shorting an output pin, or leaving out a solder trace (possibly fixable). Otherwise, it all ROM related.

[Murph24]

Fesstech,
Right, That was what I was getting at. The xda-developers forum found that problem (amongst others) with another HTC phone and they determined that without some serious skills, it was going to be nearly impossible to rework any soldering on the board. That phone was missing its needed GPS antenna and they shorted the leads where the antenna should be. So maybe there is hope, since I think we have the antenna......

[shadowmite]

No, you don't have hope for it. You're misunderstanding the documentation for the chipset. It can plex the antenna inputs all into the chip, but DOES need a tuned antenna outside the chip for proper data. Your phone lacks this. It's not going to get any better, you have the same situation as the 8525.

aGPS is supposed to use some sat data IF available, however in most applications it is NOT available, and the antenna signal levels are all sent back to sprint's location server which triangulates your position and sends it back out. Without the proper GPS antenna you have no hope of entering standalone mode properly, you'll be able to yes... But the same as the TyTN you'll end up with nothing but a noise floor signal and no hope of getting a fix.

If you notice in the diagram of your msm7500 you'll see the PCS/Cell antenna can operate alone in duplex mode, or in a triplexed mode with a DIFFERENT antenna, one that is actually tuned to the GPS bands as well. You don't have that. We'd be able to see it inside the phones case if you did (unless I'm completely blind or missing something obvious). Without that antenna it's proof the phone has been built on the duplex design instead...

[opulence]

does the 6700 have a-gps on it? if so can a java emulator be installed on it for telenav or garmin to work?

[shadowmite]

Unless you can take some pictures of a antenna grid or antenna plane in pretty close proximity to the msm7500 chip, there is no tuned GPS antenna... so go back and take one last look if you will... But I think at this point it's a 90% chance it's not there...

The 6700 has no antenna either, it's aGPS mode does not use the sat data as far as I am aware.