BG77 notification on NMEA port about fixing

Hi, I am trying to enable notifications on NMEA port. Instead of getting the informations after fixing, I am trying to get info that fixing is still in progress or didnt happen. Is it possible? I didn’t find any AT command in the datasheet.

Have you read the document below?


Chapter 2.2.1 provides clear instructions of NMEA configuration.

After you configure and enable NMEA port, you can get NMEA sentences every second.

Yes, there are many possible options to configure. But I did not find any command to display that the device is still fixing.

You need to write your own code to read the NMEA messages to understand what is happening. There is no other simple way to monitor the fix process.

So there is not any AT command that displays an information about fixing in progress? I already limited the displayed informations after fixing with QCOM and it works perfectly fine, but as I understand, there is no direct AT command for this case?

There is AT command to get a particular NMEA message at the time you issue the command, e.g. AT+QGPSGNMEA=“GSV”
However you still need to parse the message to understand what is going on.

You can also set the module to continuously stream NMEA messages to the NMEA port or auxiliary port but still you need to parse the message for proper meaning.

Either I you don’t undertstand me clearly or vice versa. On USB port i get error 516 when fixing is in progress. How to get info about this error on NMEA port? After fixing I get everything I want and I can configure diplayed informations and I know what they mean.

I believe you have used AT+QGPSLOC to get the location. Error 516 means no fix.

The above command will always give you 516 if there is no location fix. This is due to the satellites acquisition being not successful or the signal of satellites is not strong enough to calculate the location. When there is a fix, above command returns you the coordinates and time.

To understand what is going you need to examine the NMEA messages. The NMEA messages tell you about the GNSS status. You can assume the NMEA messages as debug logs. This is the only way to analyze why the fix is not successful. All the GNSS modules work in the same way. Parsing the NMEA messages is not difficult just refer to the NMEA protocol standard.

You may also ask Quectel for a PC program. This program can decode the NMEA messages and show the satellites ID and CNo on a graph. However this program can only decode GPS+Glonass and cannot decode Beidou and Galileo constellation.

But the thing is I get no sentences on NMEA port.
Port USB displays: Error X (it does not matter which error)
Port NMEA displays nothing at the time. And here is the thing I am trying to change.

Port USB displays location after executing AT+QGPSLOC?
Port NMEA displays location.

You need to enable the port before it provides you the NMEA messages.
Read and digest the document I told you previously.