How to store information base on the Sam-M8Q GNSS?

0 votes
I use ublox Sam-M8Q GNSS. This module do NOT have internal flash can store ephemeris information.  Do I need use online AGSP to GNSS every 2 hours?

As the same reason, I save current configuration (UBX-CFG) by u-center. Is it real be  stored ?
by Kelly Chuang asked Nov 8, 2018
0 votes
Configuration is stored in BBRAM only if yoy issue UBX-CFG-CFG  to store config data to BBRAM.  BBRAM persists only if V_BCKP is maintained.
Ephemeris stored in BBRAM expires in two to four hours. When ephemeris is expired, it will take 18 to 36 seconds to refresh it under good signal conditions.
AssistNow provides real or synthesized ephemeris depending upon which version of AssistNow you are using.  This shortens TTFF  to on the order of 10 seconds under good signal conditions.
by grampy answered Nov 8, 2018
by Kelly Chuang selected Nov 8, 2018
Best answer
Does  BBRAM have enough size to store ephemeris If I download 6 week ephemeris? Is it still expires  after 2 ~ 4 hours?
For AdsistNow, review the application note on implementation of Multi-GNSS AssistNow.
BBRAM can store only the current ephemeris.
BBRAM can store next orbit predicted data for some limited number of satellites as computed by AssistNow Autonomous.

AssistNow Online only provides aiding with curent live data and requires software in your host MCU.

AssistNow Offline data for 1 to 30 days requires storage and software in your host MCU.
BBRAM can store only the current ephemeris. May I askthe current ephemeris that mean 4 hours? Or 1 week?
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