[Gta04-owner] GPS fix?

[Dr. H. Nikolaus Schaller]

Am 16.11.2011 um 15:52 schrieb Neil Jerram:

> On 16.11.2011 11:37, Dr. H. Nikolaus Schaller wrote:
> 
>> I think I have found the root cause.
> 
> Ah, that's nice news; thanks for the investigation.
> 
>> The VSIM LDO is simply not switched on
>> or has been switched off by the Kernel regulator drivers.
>> 
>> VSIM should be set to 2.8V. This voltage is provided to both, the internal
>> and the external antenna.
>> 
>> It is explicitly switched on by the "gps init" command of U-Boot,
>> and all antenna tests had been done through U-Boot.
> 
> http://download.goldelico.com/gta04/unstable/src/boot.txt appears to have "gps init" in all the right places, in particular the one for a default Linux boot.  And I'm 99% sure that my current boot.scr comes from that.  So I guess that means that the kernel is switching _off_ VSIM when it boots?

Appears to be so. At least a voltmeter shows 0V.

I think initially we did do the "gps init" in U-Boot and it worked. This was before we added
the regulator drivers to the Kernel. And then, we didn't test any more in detail. Just
that the UART works...