INS, MRU, AHRS-II Firmware Update Guide

Posted by Will Dillingham on Aug 18, 2020 4:43:32 PM

Inertial Labs logo - new2-1Last Updated: July 2019

This document describes the steps of the firmware update procedure for the Inertial Labs GPS-Aided Inertial Navigation Systems (INS), Motion Reference Units (MRU), and Attitude and Heading Reference Systems (AHRS) with embedded DGPS receivers. It holds for all members of the INS family – INS-B, INS-P, INS-PD, the MRU family – MRU-B, MRU-E, MRU-P, and MRU-PD, as well as the AHRS products.
It is supposed that the user has experience with ordinary operations with the Inertial Labs INS, MRU, and ARHS units and the Inertial Labs GUI.


In order to update the firmware, it is necessary to have the following:

  • The INS/MRU/AHRS cable;
  • PC running with MS Windows XP, Vista, 7, 8 or 10;
  • Inertial Labs firmware upgrade distributive.

Begin by connecting the INS/MRU/AHRS to the PC using the cable marked as COM 1. Apply power by connecting to the power source. The INS/MRU/AHRS LED indicator will then light up yellow, then change color to red. The device is now operational.

Please find out the serial port number to which the COM1 of the INS/MRU/AHRS is connected. See “Inertial Labs™ Demo Program User’s Manual” Section 2, “Installation of drivers and configuration of PC parameters” and “Appendix A. Installation of the COM-to-USB converter drivers and configuration of PC parameters” for more details.

Before moving on, open «Device Manager» (Fig. 1) where you will see the COM ports which will be marked as «Ports (COM & LPT)». Number N in the port name is assigned by OS.

If you connected the INS/MRU/AHRS via USB through its COM-to-USB converter, then refer to Fig. 2 where the set СОМ-port is marked as «USB serial port (COMN)». Number N is the port name assigned by the PC.

Device Manager PortsFigure 1.

Device Manager

Figure 2.

Procedure of INS/MRU/AHRS firmware updating using the command line tool:

Please perform the following steps:

1. Please install the STMFlashloader using flash_loader_demo_v.2.7.0 from the "STM Flash loader" folder of the distributive. You do not need to run this program after the installation. This program is required for correct command line firmware update (please see instructions on page 5 of this document).

2. Connect the INS/MRU/AHRS to the computer and do not power it on.

3. Go to "Flash Loader Demo" folder and run file with extension .bat (the file should have the name similar to A2IMU_3_2_8_3_20190227.bat). In the opened command window type in the serial port number to which COM1 of the INS is connected in line "Enter port number:". And press Enter. The command window should look like shown on the Fig. 3.

4. Power on the INS/MRU/AHRS and press Enter. Please note that LED of the INS/MRU/AHRS should remain off.

5. Given that the above steps were followed correctly, the firmware downloading should now begin. The firmware update process includes erasing of the sectors of the INS/MRU/AHRS flash memory, downloading of the firmware, and verifying. The whole process is displayed in the command window (please see Fig. 4).

6. After the firmware was successfully updated the line "press Enter to exit" appears in command window. Press Enter to close this window.

Command window port numberFigure 3.

Firmware update

Figure 4.

Note: Please note that occasionally it can require multiple attempts (5-10) to update the firmware: if error(s) appears in the command window please repeat the process above starting with the Step 2.

7. Power down the INS/MRU/AHRS, wait approx. 10 seconds, and power it up. The LED indicator lights yellow and then turns red. The firmware update is completed and the INS/MRU/AHRS is ready for operation.

Procedure of installing STM Flash Loader Demo software
1. Locate the flash_loader_demo_v2.7.0.exe executable on the PC. This file is provided by Inertial Labs in the Firmware Upgrade Distributive (in the “STM Flash loader” folder under the “Firmware update tool”).

2. Run the executable to launch the installation wizard.

3. Follow the instructions from the installation wizard to complete installation on the PC.

4. Once installation is complete the program should appear in the program menu in Windows under “stmicroelectronics” as “Demonstrator GUI”.

Topics: MRU, AHRS, INS, INS-D, INS-DL, INS-B, AHRS-II, update, Guide, Firmware

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