I am using the GPS on my mangOH Yellow, and I wanted to understand what impacts the Time To First Fix (TTFF).
I made an app that enters ULPM for x seconds, then make a GPS fix and go back to sleep for x seconds. I tried different values for x, from 1 min to 12h.
However, it seems like the TTFF is always the same (30 seconds approximately), regardless of how much time is spent in ULPM.
Then I tried to deactivate the radio with:
$ cm radio off
And it appears that without radio, the TTFF after 6h of ULPM is bigger (something like 1min30 / 2min).
So my guess is that the board downloads some ephemeris / almanac data from a server when the radio is ON to make a fix quicker.
But I would like to know more precisely how GNSS information is dealt with on WP7702 ?
Hope someone can help, have a good day !