There are three different types of firmware:
- Stable (3.4): The recommended build for most users.
- Beta (3.5-rc1): A pre-release of a stable build, used for testing and bugfixes before officially labeling a build as stable. The versions for the these builds are suffixed with -rcx, where rc stands for release candidate, and x is a number that is incremented as the beta is updated.
- Development (3.6-dev): Development build, updated frequently. This build should only be used in practice by developers and advanced users. The versions for these builds are suffixed with -dev.
The latest stable release of ArduSub is 3.4, and it is recommended to use QGroundControl stable release 3.1.3 with version of ArduSub. Versions of ArduSub later after 3.4 require a recent daily build of QGroundControl to operate.
What Version is Installed?
To find out what firmware version is installed on your autopilot, refresh your parameters. When the parameters are refreshed, the autopilot sends its software version information via STATUSTEXT messages. You can view these messages by clicking the Messages icon in QGroundControl. The Messages icon looks like a megaphone, or a warning sign if there are pending warnings. Here, you can see that the ArduSub version is V3.5-rc1.
It is highly recommended to save your parameters to a file before updating your firmware. To update your firmware using QGroundControl, go to the Vehicle Setup Page and click the Firmware tab, then plug your autopilot into the computer with a USB cable. Click ArduPilot flight stack, and choose your desired version to load. Beta and Development options are available after clicking the Advanced settings checkbox. Stable is not yet available through QGC for ArduSub. After you have selected your desired version, click Ok and wait for the upload to complete.