Postcard RTK: Choose msm4 or msm7 message format

[amlago]

Postcard RTK: Choose msm4 or msm7 message format

I need to choose the msm4 or msm7 message format.
The Postcard settings only allow you to choose between on and off.
I would like to be able to choose between msm4 and msm7, like in the Facet settings.
Regards
Angel

[amlago]

Hi, any answers on msm7 in Postcard RTK?
I need it urgently because I need rinex with full GLONASS data, and msm4 is missing phase data.
Regards

[PaulZC]

Hi Angel (@amlago ),

The LG290P MSM selection has changed frequently over the past few weeks as we add better support for PPP logging.

For MSM7, it looks like Release 2.2 may currently be your best option?

To make it 'switchable', we will need to add a new setting with full menu, command and configuration support, and implement it on all other supported GNSS platforms. It is certainly possible, and we will add it, but it is not a 'simple' change.

I hope this helps,
Paul

In the main branch (release v2.2):

enableRTCMBase :

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 801 in 68884d8

"PQTMCFGRTCM,W,7,0,-90,07,06,2,1"); // Enable MSM7, output regular intervals, interval (seconds)

enableRTCMRover :

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 941 in 68884d8

"PQTMCFGRTCM,W,7,0,-90,07,06,2,1"); // Enable MSM7, output regular intervals, interval (seconds)

In today's release_candidate (unreleased):

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 801 in 68884d8

"PQTMCFGRTCM,W,7,0,-90,07,06,2,1"); // Enable MSM7, output regular intervals, interval (seconds)

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 941 in 68884d8

"PQTMCFGRTCM,W,7,0,-90,07,06,2,1"); // Enable MSM7, output regular intervals, interval (seconds)

In release_candidate on September 30th:

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 853 in 5e8192f

"PQTMCFGRTCM,W,4,0,-90,07,06,2,1"); // Enable MSM4, output regular intervals, interval (seconds)

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 1013 in 5e8192f

snprintf(msmCommand, sizeof(msmCommand), "PQTMCFGRTCM,W,7,0,15,07,06,2,%d", minimumRtcmRate);

In release_candidate on September 22nd:

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 853 in b3b0492

"PQTMCFGRTCM,W,4,0,-90,07,06,2,1"); // Enable MSM4, output regular intervals, interval (seconds)

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 1013 in b3b0492

snprintf(msmCommand, sizeof(msmCommand), "PQTMCFGRTCM,W,7,0,15,07,06,2,%d", minimumRtcmRate);

In release_candidate on September 19th:

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 853 in ec5b17f

"PQTMCFGRTCM,W,4,0,-90,07,06,2,1"); // Enable MSM4, output regular intervals, interval (seconds)

SparkFun_RTK_Everywhere_Firmware/Firmware/RTK_Everywhere/GNSS_LG290P.ino

Line 1013 in ec5b17f

snprintf(msmCommand, sizeof(msmCommand), "PQTMCFGRTCM,W,7,0,15,07,06,2,%d", minimumRtcmRate);

[amlago]

Hi Paul.
Thanks for your concern.
I know each change is a lot of work.
Ideally, it should be switchable between msm4 and msm7.

Regards
Angel

[cturvey]

I didn't do a comprehensive search of the usage, initially threw it at the whole of GitHub to find the string/command, but this looked like the one file in the SparkFun domain.

I suspect having it adjustable is helpful, the MSM4 are definitely more compact and a better choice in lower bandwidth radio links where size and speed/latency are considerations, and data volume for logging.

MSM4 vs MSM7 there's also a precision aspect, the doppler can be inferred, and is often used in a code vs carrier sense to identify cycle slippage. When I was checking RINEX files I'd try and map the code and carrier advancement into Hz. The expectation being about +/- 3 KHz as I recall, but this pulls one way or another depending if the receiver's local clock is fast or slow. On uBlox they measure the clock rather than try an discipline it explicitly like say LEICA, and expand the doppler search space to perhaps +/- 5 KHz to find the skewed signal.

Ideally for RINEX that we use raw measurements more directly in a native form like uBlox's UBX-RXM-RAWX, where the post-processing solves for receiver time (offset, bias, drift, etc) it ends up with more information to work with and doesn't have to un-cook things. Not sure if Quectel has a raw format or if that just generates way more data than desired.

Best Regards, -Clive

[PaulZC]

I've added useMSM7 to my pcUpdates branch - see commit 4d13e84

Only the LG290P needs this. ZED, mosaic and UM980 all have different messages for MSM4 vs. MSM7. Only LG290P has a parameter for the MSM4 vs. 7 selection .

[amlago]

Hi Paul. (@PaulZC)
Today I configured messages on msm7 with Wi-Fi settings and switched to base mode.
The messages I received are still msm4.
What could it be?
I also didn't see the msm4 to msm7 configuration in the Bluetooth serial configuration. Is that correct?
Regards
Angel

[PaulZC]

Hi Angel,

Please tell us which version of RTK Everywhere Firmware you are using. Is it the latest Release Candidate?

Please tell us which version of LG290P firmware you have installed.

Please tell us if you have Galileo HAS enabled.

The MSM Selection option should be available in: the Configure GNSS Messages menu; and in the Base \ RTCM Messages menu.

If I enter WiFi web config mode, change that setting, save and exit, I see the change:

If I then put the Postcard into Base mode, give it WiFi credentials, enable NTRIP, I see MSM7 on RTK2go:

All seems well?

Best wishes,
Paul

[amlago]

Hi Paul
In short, after a couple of reboots it worked.
The strange thing is that yesterday I switched to msm7 with Wi-Fi config and it was still in msm4 despite the msm7 check mark.
I also found it in Bluetooth config, my apologies. It must be due to tiredness from the workday.
I'm using the latest v2.3 from 10/15 and v06 test for the LG290p.
It works fine.
I don't know if it needs an extra reboot to get it right.
Thanks, Paul.

[PaulZC]

No problem Angel!

It certainly needs Base to be restarted. But exiting WiFi web config into Base should do that. So should exiting the menu after changing the MSM7 option. There is a restartBase check in both menus. But maybe I missed something?

We appreciate the feedback. The firmware has so many options, combinations and configurations, it is (almost) impossible for us to test them all. Feedback like this helps us ensure we've covered all the options. If this happens again, please tell us the exact sequence of events, and we will try to capture it and correct it.

Have a great day!
Paul

[amlago]

Thank you very much, Paul.
It was a pleasure working with you.
Best regards
Angel

[TCIII]

@PaulZC
I have been following this issue with great interest as I was given a Sparkfun LG290P RTK GNSS Breakout board that I would like to use as a Rover and to use it with my RTK Postcard/Portability Shield Base Station which I have currently working with my Sparkfun ZED-F9P RTK GNSS Breakout board as a Rover.

It is my understanding that the Sparkfun LG290P RTK GNSS Breakout board can only achieve a RTK Float solution unless it is receiving MSM7 messages? If that is the case then do both the RTK Postcard/Portability Shield Base Station and the Sparkfun LG290P RTK GNSS Breakout board Rover have to be running the LG290P03AANR01A06S_PPP_TEMP0829.pkg firmware as well as the RTK Postcard/Portability Shield Base Station running the RTK_Everywhere_Firmware_RC-Oct_15_2025.bin firmware?

Presently my RTK Postcard/Portability Shield Base Station is running the RTK_Everywhere_Firmware_RC-Oct_15_2025.bin firmware but the RTK Postcard LG290P is running the LG290P03AANR01A05S firmware as well as the Sparkfun LG290P RTK GNSS Breakout board Rover.

Comments?

Regards,
TCIII