SB006 Alta X – Out of RAM

Date Released: 10/14/2022

Subject: Cube Flight Controller Memory Management

Effectivity: Alta X on 1.3.6 and older.

Require Action: Modify workflow

INTRODUCTION

This service bulletin is being issued to alert all Alta X operators of an issue where logging fails to start when WiFi or TELEM 2 is enabled, due to insufficient memory. In order to work around this issue, users can choose between having communications enabled for the FRX Pro, or for WiFi, but not both simultaneously. Read below to see how to properly set up parameters. If you have any questions or concerns, or if you are currently using TELEM 2 for an integration, please contact Freefly Systems Support.

BACKGROUND

One customer has reported an error where flight logs were unavailable after a flight while operating on firmware version 1.3.6. The root cause of this was that there was not enough free RAM(memory) in the flight controller to allow logging to begin. Each additional feature that is enabled on the flight controller will utilize additional RAM. In the case of Alta X, FRX communication is always enabled by default. When also enabling WiFi communication or TELEM 2, there may not be enough RAM available to start logging. Furthermore, disabling WiFi was a complex process, requiring the end user to manually edit multiple parameters.

DISCUSSION

Some key points to convey regarding this issue:

• The issue affects logging when multiple MAVLink communication links are enabled simultaneously.
  • FRX Pro and WiFi both require a MAVLink communication link to be enabled to operate.
• The issue does not endanger safe operation of the aircraft. Flight critical systems have the RAM that they need pre-allocated before flight, and PX4 will stop new processes from running if there is not enough RAM.

RECOMMENDATION AND ACTION ITEMS

For most use cases, users can choose between having communications enabled for the FRX Pro, or for WiFi, but not both simultaneously. If you are using TELEM 2 for other applications, you can contact Freefly Systems for further assistance.

We have updated the WIFI parameter files on our support page. We recommend users download these parameter files and utilize them for enabling or disabling WiFi. When using these parameter files, the associated MAVLink streams are properly managed to reduce RAM usage.

• When WiFi is enabled using these new param files, FRX Pro communication is automatically disabled.
• When WiFi is disabled using these new param files, FRX Pro communication is automatically restored.

All future Alta X aircraft will ship with these parameter files included in the SD card.

Freefly Systems is actively working on a firmware update that will mitigate this issue completely. Be sure to sign up for future notifications to ensure you are alerted when the firmware fix is released.