L76 default NMEA sentence

IoT Modules GNSS Module
1

Hi all,

I am trying to set the default NMEA sentence of a L76B module to output only the GNRMC sentence.
I have been looking into the SDK commands as well as the PTMK. I know that I can set the configurations with the PTMK314 sentence but I would like to make it permanent.

Is it possible? If so, how?

Thanks in advance!
Best regards

2

Hi Ledeir,

As you said, the PTMK314 command can be set, but if the module is completely powered down, the set parameters will be lost. If you want to save permanently, you need to keep the module’s V_BCKP pin powered at all times and keep the RTC area active, because the saved commands are stored in the module’s RTC area.You can check out this documentation for V_BCKP pins.
Quectel_L76&L76-L_Hardware_Design_V3.2.pdf (840.6 KB)

3

Thanks @link.shan-Q,

I just thought that maybe there could be a SDK command for the default NMEA sentence that could place the option in the Flash.

4

Hi Ledeir,

There is currently no SDK command to set the NMEA statement.

Best regards

5

Hello @link.shan-Q,

into the L76 Hardware Design document you have attached, at page 11 I can read:

"The embedded flash memory provides the capacity for storing user-specific configurations and future
firmware updates."

I need to set the update rate to 5Hz instead of the default 1Hz value and to keep it stored in the flash even when the RTC area is not active (in case battery voltage drop after long time the circuit is not powered on and the V_BCKP pin goes LOW).

Is the flash suitable for this purpose? And where can I find AT command or whatever I should set to achieve this goal?

Thanks in advance e best regards.

Giulio

6

Hello giulio.iselqui，

I’m really sorry for not seeing your message in time.You can use the PMTK220 command to set the output frequency, but this configuration is not saved in FLASH, refer to the protocol documentation for command Settings.
Quectel_L76_Series_GNSS_Protocol_Specification_V3.3.pdf (947.9 KB)

7

Hello link.shan-Q,

no problem for the late reply, thank you anyway. Ok, so no chance to save this setting into the flash memory. Got it.

But then what is the meaning of the quote I have reported in my previous message and that was taken from L76 Hardware Design document “The embedded flash memory provides the capacity for storing user-specific configurations and future firmware updates.” ?

What kind of user-specific configurations can be stored into the flash memory?
Can you clarify this point please?

Thanks

Best regards

Giulio

8

Hi giulio.iselqui,
The SDK command configuration developed by Quectel can be written into FLASH. Please refer to the SDK command in the attachment.
Quectel_GNSS_SDK_Commands_Manual_V1.4.pdf (810.0 KB)
Thanks

Best regards