How to use the EASY A-GPS functionnality on pytrack's GPS ?

[daraujo]

Hi,

Because of bad conditions the pytrack's GPS has not been able to get an acceptable time to first fix (TTFF), it usually needs 40min to several hours for the first fix but there is no problem to fix a position after that.
In the Quectel L76 documentation, there's a EASY function that would allow to get a TTFF way smaller.
The problem is that beside a PMTK command to enable the function there's no information on how to use it in the GPS or pytrack documentations.

Has anyone tried or know how to use this function ?

[crumble]

@WilkinsSq

EASY is not A-GPS. Easy writes the collected almanac into internal flash memory. Depending on the settings this data is used when it is not older than 3 hours.

[WilkinsSq]

@crumble

Hi, I'm quite new to A-GPS and I'm trying to test for myself the effect it has on TTFF compared to simple GPS. Based on what you said, am I correct in thinking that we need to provide the ephermeris data and almanac to the Pytrack for the Quectel L76 chip to perform A-GPS using the EASY function?

Regards
WilkinsSq

[crumble]

The L76 uses an internal flash. If EASY is set, you don't need to send special sentences. You can send it to sleep before switching the power off.

The almanac used by EASY can be uploaded as well, but the format is behind a paywall.

Anyway it has to find a few satellites . And with this small antenna it has only a small chance :( As well I sometimes think it it the wrong antenna. It is able to find some sats under bad conditions and some never. Maybe directions are important.