DS-015 Get detailed Node functions/capabilities

[pavel.kirienko]

We need to start with the basic question: why is it helpful to know the functionality of a node beyond the set of the ports it provides?

With the currently proposed register API, one can determine whether a node has a port by its name (that is, by the final component of the register name like uavcan.pub.mangnetic_field_strength). Proper naming provided, this should be enough to provide some minimum degree of introspection for basic applications.

This method notably lacks the type information. It was noted a long time ago in GUI Tool – Next Generation - #24 by pavel.kirienko, where a solution was proposed:

@pavel.kirienko

The [proposed] solution is to further extend the register naming conventions by adding a new name pattern: uavcan.type.* , where the asterisk stands for the port name – e.g., uavcan.type.servo_angle_roll – the value contained in the register will be the name of the data type together with the major version number, like uavcan.si.angle.Scalar.1.

Although the specified pattern lacks the pub/sub differentiation, so it should be factored in as well. It is not mentioned in the quoted excerpt but the register would be read-only (persistent, immutable).

Currently, it is probably out of the scope of the DS-015 MVP effort, but I expect that it will become relevant after the first version of the standard (DS-015) is released, along with a few other more advanced features.

FYI @TSC21