saving and restoring GPS data for U-blox chip quicker startup
vasco.nevoa at sapo.pt
Sun Aug 31 02:25:10 CEST 2008
Abdelrazak Younes wrote:
> There is at least two that I know of, some ruby script:
> And some python script in the FSO framwork. Look
Cool. What's the requirements to get alphaone's ruby scripts working in
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 :-)
>> So, I took the protocol datasheet
>> 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.
> 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
>> 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!
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