[/nao_audio/master_volume] responded with an error: service cannot process request: handler returned invalid value

[FelipMarti]

Hello,

I'm trying to use the nao_audio node of the nao_interaction package to change the volume of NAO, but I'm having the following error when calling the /nao_audio/master_volume ROS Service:

$ roslaunch nao_bringup nao_full_py.launch nao_ip:=nao.local

$ roslaunch nao_interaction_launchers nao_audio_interface.launch nao_ip:=nao.local

$ rosservice call /nao_audio/master_volume "master_volume:
  data: 0" 
ERROR: service [/nao_audio/master_volume] responded with an error: 
service cannot process request: handler returned invalid value: 
Invalid number of arguments, args should be [] args are(<class 'std_srvs.srv._Empty.EmptyResponse'>,)

I'm using ROS Kinetic, however, I'm not sure if this error is related to the ROS version. I'm not very familiar with ROS in Python, but I had a look to the node nao_audio/nodes/nao_audio.py

All the returns are:
return EmptyResponse

Shouldn't be?:
return EmptyResponse()

I have replaced all the returns and now I have this error:

$ rosservice call /nao_audio/master_volume "master_volume:
  data: 0" 
ERROR: service [/nao_audio/master_volume] responded with an error: 
service cannot process request: handler returned invalid value: 
Invalid number of arguments, args should be [] args are(,)

Any suggestions?

Thanks!

[kochigami]

Hello,

I had the same error in ros indigo, and I found that returning value of service handler was wrong.
self.handleAudioMasterVolumeSrv uses AudioMasterVolume as service message, and I think it should return AudioMasterVolumeResponse, not EmptyResponse,

I just fixed it in #10.
I found same lines in another service handlers. I'll fix it in a next pull-request.