Activating the L26-P function

IoT Modules GNSS Module
27

Hi! To get a fixed solution in RTK mode, I use the program SurPad. SurPad collects data from the L26-P, some of which it sends to the base station, and in response it should receive corrections from the base station. But it does not receive them, because the base station either incorrectly determines my coordinates, or does not receive the necessary data. I think it’s about some of the NMEA messages.

28

Hi! How do I switch from NMEA messages to RTCM and back?

29

I think I need to switch from NMEA 0183 Rev 3.01 to Rev 4.10. And then the problem will be solved. How do I do this?

30

Or on NMEA rev 3.01, configure message passing: $ GAGSV, $ GNGGA, $ GNGLL, $ GNGRS, $ GNGST, $ GNRMS, $GNVTG, $ GNZDA, $ GPGSV.

31

Hi，

Is the differential data of the base station to be sent to L26P, so that L26P outputs high-precision position information?

Best Regards

32

Hi，
Still confirming, please wait.

Best Regards

33

Good afternoon! L26-P itself can receive corrections and output high-precision information? Or should an external application (for example, SurPad, RTKLib) do this? How do I switch to NMEA ver 4.10?

34

Hi,

No, L26P must require an external algorithm.I just confirm it. I don’t know much about SurPad.

switch from NMEA 0183 Rev 3.01 to Rev 4.10：
$PSTMSETPAR,1122,0x04 //Set the NMEA version to 4.1
$PSTMSAVEPAR
$PSTMSRR

switch from NMEA 0183 Rev 4.10 to Rev 3.01：
$PSTMSETPAR,1122,0x0c //Set the NMEA version to 3.01 (default)
$PSTMSAVEPAR
$PSTMSRR

Best Regards

35

Thank you very much!

36

Something completely confused. After switching to NMEA rev 4.10, everything should have worked, but SurPad did not accept the amendments, and does not accept them. In addition, the SurPad stops the L26-P module after a minute. Reconnection is only possible after the power is reset from the module. What could be the problem?

37

Maybe it’s because of the data transfer rate? Please write what commands you use to switch the speed.

38

Hi，
The baud rate can be configured through the $PSTMCFGPORT.
For example, the command to configure the baud rate to 460800 is as follows:
$PSTMCFGPORT,0,0,1,460800
$PSTMSAVEPAR
$PSTMSRR

Best Regards

39

Hi，
I am also curious, does SurPad have updated software to adapt and parse the data output by L26P? The default output of L26P is standard NMEA protocol and proprietary protocol.

Best Regards

40

In SurPad, you can select other hardware that uses the NMEA protocol. My other module from Allystar, connected to the same debug board, running on NMEA 4.10, in SurPad gets the fixes and doesn’t shut down after a minute.

41

Hi，
Sorry for the late reply.
NMEA switches to RTCM:
$PSTMSETPAR,1227,9,2
$PSTMSAVEPAR
$PSTMSETPAR,1227,20020,1
$PSTMSAVEPAR
$PSTMSRR

RTCM switches to NMEA:
$PSTMSETPAR,1227,9,1
$PSTMSAVEPAR
$PSTMSETPAR,1227,20020,2
$PSTMSAVEPAR
$PSTMSRR

Note that the commands must be sent in the above order.

Best Regards

42

Hi，
You can compare the output difference between L26P and Allystar.
In addition, if SurPad can choose the RTCM protocol, maybe you can try it.

Best Regards

43

Hello! Thanks! I compared the NMEA 4.10 L26-P code and Allystar. The difference is obtained in the following lines: $$GNGRS, $$GAGSV. L26-P does not output them.

44

Hi，

I think it not be caused by these two sentences $GNGRS and $GAGSV. Maybe you can check with SurPad’s engineers.

Best Regards

45

Hello! I have already contacted the manufacturers of SurPad, they replied that they did not test with this module and can not say anything. Can you recommend a program on Android so that I can implement RTK mode with L26-P in it?

46

Hi，
Sorry, I don’t have any recommendation of this kind of program.
What is the application scenario of the product? In-vehicle application?

Best Regards