Faster acquisition time

I am using the L76 GPS module on a mobile device that is completely powered off between uses. This is on an emergency vehicle. Acquisition time is not too bad but I’d like to make it better if possible. Is there some data that I can suck out of the module and save it in non volatile memory so that the next time the unit is used I can restore that data to the L76 to help it acquire faster?

Please read <Quectel_L76_Series_Hardware_Design_V3.1.pdf> and apply VBCKP.
Also, there are several modes possible to improve TTFF: EASY, EPO, LOCUS.

Dear Sir,
Sorry for delay in respond , if you power the module completely or send it into low power mode?
If you power it off complicity then in order to improve the Acquisition time you can send a command to inject location and time ( Location <50 km and time <2 sec) please use PMTK 740 and PMTK 741 commands

Thank you. I will try this.

I have tried the PMTK740 and 741 commands to try to speed up TTFF. I also tell it to do a hot start rather than the power-up’s cold start. I think there is a marginal improvement.

Does the order matter? e.g. hot start, sent time, send position vs send position/time then do a hot start?

I think I might do better still if I could send it EPO information. I would save ephemeris, and position (I know the time) and load it on power up. For example does the PMTK721 work on the L76?

None of the Quectel documentation I found has a comprehensive list of PMTK commands that the L76 will respond to. For example, it doesn’t list the PMTK741/740 commands you recommended. Clearly the L76 does understand them because I get an acknowledge response. Can you point me to more complete documentation?

Thank you for your continued support.
This is for an emergency vehicle so its important.

Best regards
Bill Brown

Dear Customer,

Please download related info from the link as below:
https://cnquectel-my.sharepoint.com/:f:/g/personal/europe-fae_quectel_com/ElMZuYozYhtHsiL7SY2U5HQBl9Wn6A5HGNA0GCQ_VA60ww?e=hYYY6b

Best Regards

This is terrific. It will save me a lot of trial and error. Thank you very much
However after reading the documentation I have more questions

Is it possible to extract the EPO from the L76 chip directly once the satellites are acquired?
I had hoped that the data we get with the xxGSV sentence would be sufficient to speed re-acquisition from a cold start.
But after reading the documentation you sent, I see that the EPO data is more complex and the implication is that it is only downloadable from the cloud.
Can I get it from the chip?

Dear bbrown1,
Host EPO is a on-line AGPS feature. The EPO file cannot be generated by the L76 chip. Since the device is completely powered off, EASY is not available at next power up. Injecting current UTC time and approximate location is the simple way to speed up TTFF.

Best Regards