AP_DDS: Parameters service

[PQuill33]

ISSUE

#28292

Changes

-Add set parameters service call to AP_DDS library

• service is /ap/set_parameters
• Add get parameters service call to AP_DDS library
• service is /ap/get_parameters

Test

Using ros2 CLI, launch ardupilot sitl

ros2 launch ardupilot_sitl sitl_dds_udp.launch.py transport:=udp4 synthetic_clock:=True wipe:=False model:=quad speedup:=1 slave:=0 instance:=0 defaults:=$(ros2 pkg prefix ardupilot_sitl)/share/ardupilot_sitl/config/default_params/copter.parm,$(ros2 pkg prefix ardupilot_sitl)/share/ardupilot_sitl/config/default_params/dds_udp.parm sim_address:=127.0.0.1 master:=tcp:127.0.0.1:5760 sitl:=127.0.0.1:5501

• Check that parameter service is up

ros2 service list

Expected output

• Service call to set parameter

ros2 service call /ap/set_parameters rcl_interfaces/srv/SetParameters "{parameters: [{name: LOIT_SPEED, value: {type: 2, integer_value: 1250}}]}"

Expected output
mavproxy window:

service call window:

• Service call to get parameter

ros2 service call /ap/get_parameters rcl_interfaces/srv/GetParameters "{names: ['LOIT_SPEED']}"

Expected output
mavproxy window:

service call window:

[tizianofiorenzani]

I have tested with the Plane SITL, trying to ask for a wrong parameter. I mispelled AIRSPEED_CRUISE, which should be 22.0, and I expected to get some error. The only thing that tells me the response is wrong is the type = 0.

ros2 service call /ap/get_parameters rcl_interfaces/srv/GetParameters "names: [AIRSPEED_CRUIS2E]"
waiting for service to become available...
requester: making request: rcl_interfaces.srv.GetParameters_Request(names=['AIRSPEED_CRUIS2E'])

response:
rcl_interfaces.srv.GetParameters_Response(values=[rcl_interfaces.msg.ParameterValue(type=0, bool_value=True, integer_value=19513347822207839, double_value=22.0, string_value='', byte_array_value=[], bool_array_value=[], integer_array_value=[], double_array_value=[], string_array_value=[])])

Instead, if you ask for the correct parameter I have:

ros2 service call /ap/get_parameters rcl_interfaces/srv/GetParameters "names: [AIRSPEED_CRUISE]"
waiting for service to become available...
requester: making request: rcl_interfaces.srv.GetParameters_Request(names=['AIRSPEED_CRUISE'])

response:
rcl_interfaces.srv.GetParameters_Response(values=[rcl_interfaces.msg.ParameterValue(type=3, bool_value=True, integer_value=19513347822207839, double_value=24.0, string_value='', byte_array_value=[], bool_array_value=[], integer_array_value=[], double_array_value=[], string_array_value=[])])

Overall seems correct. I have tried to set and get multiple parameters, changed the airspeed in flight, made sure it was effective.

[PQuill33]

I have tested with the Plane SITL, trying to ask for a wrong parameter. I mispelled AIRSPEED_CRUISE, which should be 22.0, and I expected to get some error. The only thing that tells me the response is wrong is the type = 0.

ros2 service call /ap/get_parameters rcl_interfaces/srv/GetParameters "names: [AIRSPEED_CRUIS2E]"
waiting for service to become available...
requester: making request: rcl_interfaces.srv.GetParameters_Request(names=['AIRSPEED_CRUIS2E'])

response:
rcl_interfaces.srv.GetParameters_Response(values=[rcl_interfaces.msg.ParameterValue(type=0, bool_value=True, integer_value=19513347822207839, double_value=22.0, string_value='', byte_array_value=[], bool_array_value=[], integer_array_value=[], double_array_value=[], string_array_value=[])])

Instead, if you ask for the correct parameter I have:

ros2 service call /ap/get_parameters rcl_interfaces/srv/GetParameters "names: [AIRSPEED_CRUISE]"
waiting for service to become available...
requester: making request: rcl_interfaces.srv.GetParameters_Request(names=['AIRSPEED_CRUISE'])

response:
rcl_interfaces.srv.GetParameters_Response(values=[rcl_interfaces.msg.ParameterValue(type=3, bool_value=True, integer_value=19513347822207839, double_value=24.0, string_value='', byte_array_value=[], bool_array_value=[], integer_array_value=[], double_array_value=[], string_array_value=[])])

Overall seems correct. I have tried to set and get multiple parameters, changed the airspeed in flight, made sure it was effective.

The error gets reported as a GCS message. It should read AP: DDS: Get Parameters Request : ONE OR MORE PARAM NOT FOUND.

I was thinking of populating the fields in the response message with bogus entries if that sounds like an acceptable error response?

[tizianofiorenzani]

I think it's fair to just use the type field to check whether a parameter is valid.