[LC29HEA] Support for Aiding Commands to improve TTFF without RTC battery?

IoT Modules GNSS Module
1

Hello,

I am currently developing a product using two LC29HEA modules in Moving base

I did not include an RTC backup battery (the V_BCKP pin loses power when the main system is turned off). As a result, the modules perform a Cold Start every time the system powers up, which increases the Time To First Fix (TTFF).

However, I noticed in my UART boot logs that the LC29HEA sends these specific messages right before outputting standard NMEA:

Plaintext$PAIR011,001*27 $PAIR010,1,-1*16 $PAIR010,2,-1*15

I suspect $PAIR010,2,-1*15 is an Aiding Request for the last known position and time. I can easily save the position/time before shutdown and inject it back at boot.

My questions are:

  1. Does the LC29HEA firmware fully support receiving Aiding data (Time and Reference Position) via UART to speed up the TTFF during a cold start?
  2. If yes, what is the exact $PAIR command (or standard NMEA command) I should send to answer the $PAIR010 request and inject this data?
  3. Is there any specific documentation or application note regarding Aiding/EPO injection for the LC29H series?

Thanks in advance for your help!

2

Hi @zizouth

Please refer to the following answer to your questions

  1. Does the LC29HEA firmware fully support receiving Aiding data (Time and Reference Position) via UART to speed up the TTFF during a cold start?
    Yes

  2. If yes, what is the exact $PAIR command (or standard NMEA command) I should send to answer the $PAIR010 request and inject this data?
    You can use both PAIR590: PAIR_TIME_SET_REF_UTC and PAIR600: PAIR_LOC_SET_REF to send reference time and location for aiding TTFF

  3. Is there any specific documentation or application note regarding Aiding/EPO injection for the LC29H series?

I will send you the documentation via email. Please let me know if you have received it

Best regards,