GPS

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Revision as of 18:56, 6 October 2009 by FreeTim (talk | contribs) (→‎Mojo: Quick summary of the GPS mojo features)
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GPS

The GPS hardware page.

Software found elsewhere (location services - see SDK.)

Description

The Palm Pre has a built-in hardware GPS for location services.

Google shows some misleading information out there, because the initial tear-downs didn't spot a separate GPS chip it was earlier thought the Palm Pre didn't have a GPS and thus must rely on cell phone tower location. I found misleading detail on several reviews:

The Pre does use the assisted GPS capabilities of the Qualcomm baseband. That means the phone will not be able to get a location fix when it is not connected to the cellular network.


This isn't entirely accurate - the Palm Pre does indeed have integrated GPS hardware, and uses GPS if it's turned on (enabled.)

  • If the GPS is on, GPS hardware will be used.
  • If the GPS is turned off in Location Services, the Palm Pre will fallback on cell tower location.



Location of Chip

The GPS hardware is physically located on the Comm board, right hand side, as part of the OMAP3 chipset (PDF file),

According to magazine PCB007, the Pre's main comm chipsets include the RFR6500 receiver and RFT6150 transmitter. Is it possible, the GPS isn't part of the MSM6801 but rather it's part of the Qualcomm RFR6500 Receiver, also on the Palm Pre?

Phone wreck shows the RFR6500 too, in the teardown.

I discovered that this chip, RFR6500 by Qualcomm, supports both GPS receiving and the voice part which is CDMA2000. Therefore my conclusion that the Palm Pre's GPS is inside one of the two Radio Frequency support chips, the RFR6500 receiver.

There is an engineering report here. (above, engineering report article)

Where you'll find that Qualcomm’s RFR6500 is a receiver that can support GPS and CDMA2000 voice.



References

Mojo

There are Mojo methods detailed in the SDK under Location Services (and so, no need to also detail them here.) Overview: Some of the Mojo functions allow to get current location, to subscribe to services (thus continually updating coordinates) and also reverse address resolution - put in an address and return the longitude/ latitude.

Known Issues

Apparently the software on the Pre currently isn't doing Southern Hemisphere correctly.