AP_DDS - Multiple Battery interface

[tizianofiorenzani]

Multiple battery monitor interface to AP_DDS

I would like to share information of all the available battery monitors through the DDS interface with my companion PC.

Proposed solution
Currently we share one battery instance with the topic ap/battery/battery0 of type sensor_msgs/msg/BatteryState.

A simple solution would be to use the same topic to publish all the available instances up to AP_BATT_MONITOR_MAX_INSTANCES , using the frame_id in the header to report the battery ID.

Alternatively

• Rename the topic to ap/battery/batteries

Platform
[x ] All
[ ] AntennaTracker
[ ] Copter
[ ] Plane
[ ] Rover
[ ] Submarine

[Ryanf55]

Let's

• Update the topic to be /ap/battery
• Use the frame ID to differentiate the instances
• Instead of publishing for each instance in AP_BATT_MONITOR_MAX_INSTANCES, I would recommend using AP_BattMonitor::BattMonitor_State::type and publishing when the type is NOT equal to NONE. You can still iterate through the instances with AP_BATT_MONITOR_MAX_INSTANCES, but publishing battery data for batteries that aren't configured is a waste of data.

[tizianofiorenzani]

@Ryanf55 that seems like a plan, I can work some software out and create a PR so we can discuss on that.

[tizianofiorenzani]

Here is the PR: #28291