GPS software not working well with built-in receiver

7 Jun 2017

Some older GPS application software (apps) may not immediately work well with the integrated U-Blox NEO M8 series GNSS receiver in the Mesa 3 or Mesa 2 with Windows. Possible causes and solutions are as follows.

Newer U-Blox receivers output some proprietary binary UBX data along with the standard NMEA data. This additional data provides information regarding the receiver which is not contained in the standard data. Not all apps have been written to interpret the additional data, so most just ignore it (such as ESRI ArcPad and StarPal HGIS). But some apps (such as Farmworks Mobile) may not be able to ignore the unrecognized additional data, leading to issues with GPS input in the app.

If your app is not able to handle the additional UBX data, it is technically possible to change the receiver to strictly output standard NMEA data only. But the process to do this can be difficult.

For best compatibility with such older GPS apps, we recommend either rolling back to the legacy version 2.30 of both the U-Blox Location Sensor driver and VCP (Virtual COM Port) driver, or just remove the custom u-Blox drivers altogether to instead use the generic Microsoft VCP (Virtual COM Port, or USB-to-Serial) driver. See the following web page for files and instructions.

Internal GNSS driver options for Mesa 3 and Mesa 2 with Windows

These drivers can be viewed in Device Manager under Sensors as well as under Ports (COM & LPT) respectively. You may be able to Roll Back each driver. If this option is not available, then you may need to locate and use an installer for the older drivers, perhaps uninstalling the newer drivers first. If the operating system automatically updates to a newer driver after installing the older driver, you may then need to Roll Back each driver (which should prevent further automatic updates of these drivers). You should probably perform a Restart to make sure the older drivers are truly loaded.

After you have the U-Blox 2.30 or Microsoft drivers installed and loaded, you can then use Geode Connect to "Reset Receiver" to recommended defaults. You may additionally or alternatively need to use u-Center to change USB port output from UBX+NMEA to just NMEA only.


July 2016

If GPS software that you have installed can connect to the built-in GNSS (GPS) receiver but can only see one or a few NMEA sentences and not all that are needed, some possible causes and solutions are as follows.

By default, the built-in U-Blox NEO M8N (or optional M8T) receiver in the Mesa 2 and newer Allegro 2 / Archer 2 units outputs the "GNSS" NMEA version sentences that now start with a “GN” Talker ID header instead of specific headers for each satellite constellation such as “GP” for GPS or “GL” for GLONASS separately. GPS software should be updated to support this GNSS standard.

If GPS software can not be immediately updated, on the Mesa 2 either the “Internal GNSS receiver configuration tool” (Geode Connect) or the uBlox u-Center app can be installed and used to change the output back to previous standard (as briefly explained below).

On the Allegro 2 and Archer 2, you may be able to change this under Start > Settings > System > GNSS > NMEA Sentences tab by simply enabling the "GNSS System Compatibility Mode" as explained in the manual. If this is not sufficient, then you may also need to verify that all needed NMEA sentences and GNSS System settings are enabled.

Using Geode Connect is a simpler method to do this. For technically changing the NMEA sentences on the Mesa 2 after installation of U-Blox u-Center, follow these steps.

  1. Open u-Center.
  2. If the receiver is not already connected, tap on the Receiver tab at the top > Port > COM5. It should then connect.
  3. Once connected, tap on the View tab > Configuration View. Expand the window as needed.
  4. In the list of different settings types on the left, select “NMEA (NMEA Protocol)”.
  5. You may need to rotate the Mesa 2 to landscape display orientation (and/or use the bottom horizontal scroll bar to scroll to the right) to be able to see the “Main Talker ID” and “GSV Talker ID” settings drop-down boxes.
  6. Change the Main Talker ID to “1 – GP (GPS)” and the GSV Talker ID to “1 – Use main Talker ID”.
  7. Tap on the Send button in the bottom-left corner.
  8. Validate that NMEA sentences now have the “GP” instead of “GN” talker ID header by tapping on the View tab > Text Console.
  9. If you would like to make these settings changes permanent, go back to View > Configuration View, tap on the left “CFG (Configuration)”, make sure “Save current configuration” is selected, and in the Devices box that at least “Flash” is highlighted, and then again tap on the bottom-left Send button.
  10. Exit u-Center and verify using COM5 in GPS software (at whatever baud rate).

Also, the default protocol for the U-Blox NEO M8 receivers is NMEA version 4. Many older apps are based on NMEA version 2.x. So, either the app needs to be updated, or if needed you can similarly use uCenter to change the protocol back to previous standard version for compatibility.