saving and restoring GPS data for U-blox chip quicker startup

[Vasco Névoa]

Abdelrazak Younes wrote:
> There is at least two that I know of, some ruby script:
> http://docs.openmoko.org/trac/browser/developers/alphaone/u-blox
>
> And some python script in the FSO framwork. Look 
> "framework/subsystems/ogpsd/"
>   
Cool. What's the requirements to get alphaone's ruby scripts working in 
OM2008.8?
Aside from "opkg install ruby"...
>> I'd like to see the freerunner's GPS do the same any other GPS device
>> does: save the almanac/ephemeris data to storage upon shutdown and
>> restore it upon powerup.
> Right. I just receive my freerunner today. So I may start my own plan 
> this week :-)
>
>   
Excellent. :)
>> So, I took the protocol datasheet
>> (http://www.u-blox.com/customersupport/gps.g3/ANTARIS_Protocol_Specification(GPS.G3-X-03002).chm)
>> and tried to coerce the chip into vomiting the stored information (we
>> should take care to do it after working for at least 2 or 3 minutes with
>> a good reception level).
>>     
>
> A better solution would be to just configure the Ublox to send the 
> ephemerises and almanacs as soon as they are received. 
I didn't know that was even possible... great!
> A simple daemon 
> would watch for these messages and store them appropriately when they 
> are received.
>
>   
Makes sense.
> Yes. The FSO is capable of doing that AFAIU. I have some code that do 
> that in C++ already, I'll publish them as soon as I port them to the FR. 
> My code will be able to read and decode a number of messages, including 
> raw data (pseudorange measurements).
>
>   
Wonderful. Just make sure you're not duplicating efforts with someone 
else... :)
>> 2 - a simple hook into the UI gps on/off button script, forcing process
>> (1) to ask for info and store it on file upon gps shutdown, and to
>> rewrite that info into the chip on startup.
>>     
>
> I don't think we need any manual intervention here. The above described 
> daemon should just be reading only the device. Another program should be 
> responsible of writting the aid data as soon as the GPS is started. 
> Ideally this program could also be able to write manually encoded 
> messages based on commonly used formats for ephemerises (RINEX) and 
> almanacs (Yuma).
>
>   
>> Who's working on this? I'd happily beta-test it.
>>     
>
> I will, hopefully in the coming weeks :-)
>
>   
Fine. Keep us posted!
> Abdel.
>
>