Configure QTrobot TTS language

Overview

signal_cellular_alt  Level:  Intermediate
track_changes  Goal:  learn about how to set a language of QTrobot TTS
task_alt  Requirements:

•   Quick start with coding on QTrobot
•   Create a ROS python project
•   QTrobot interfaces using ROS Services

Note

This tutorial is for the customers how bought additional TTS languages!

In this tutorial you will learn how to set a language for QTrobot Speech interface.

Create a python project

First we create a python project for our tutorial. let's call it tutorial_qt_speech and add the required python file:

cd ~/catkin_ws/src
catkin_create_pkg tutorial_qt_speech rospy roscpp -D "Set QTrobot TTS language"
cd tutorial_qt_speech/src
touch tutorial_qt_speech_node.py
chmod +x tutorial_qt_speech_node.py

Code

Now lets see how we can change a voice (language) of QTrobot. Following are some standard supported languages:

•  en-US (American English)
•  fr-FR (French)
• de-DE (German)

You may have different languages installed on your QTrobot. This tutorial will use English and French language.

Open the tutorial_qt_speech_node.py file and add the following code:

#!/usr/bin/env python3
import sys
import rospy
from std_msgs.msg import String
from qt_robot_interface.srv import *

if __name__ == '__main__':
    rospy.init_node('my_tutorial_node')
    rospy.loginfo("my_tutorial_node started!")

    # define a ros service
    speechConfig = rospy.ServiceProxy('/qt_robot/speech/config', speech_config)

    # define a ros service
    speechSay = rospy.ServiceProxy('/qt_robot/speech/say', speech_say)
    
    # block/wait for ros service
    rospy.wait_for_service('/qt_robot/speech/say') 
    
    # block/wait for ros service
    rospy.wait_for_service('/qt_robot/speech/config') 
   
    try:
        status = speechConfig("en-US",0,0)
        if status:
            speechSay("Hello, I am speaking English")
            status = False
        rospy.sleep(1)
        status = speechConfig("fr-FR",0,0)
        if status:
            speechSay("Bonjour, Je parle français")
        

    except KeyboardInterrupt:
        pass

    rospy.loginfo("finsihed!")

Explanation

ROS Services are defined by srv files, which contains a request message and a response message. First we import all from qt_robot_interface.srv. This will import all srv files that are under qt_robot_interface.srv. We need to use speech_config.

Tip

How do we know which service an interface uses? well, There is a useful command in ROS which tells you that:

rosservice info /qt_robot/speech/config
Type: qt_robot_interface/speech_config
Args: language pitch speed
...

Then we defined a service /qt_robot/speech/config and call rospy.wait_for_service() to block until a service is available. Finally we called a ROS service with a wanted language and if everything is ok service will return "True". After that we call /qt_robot/speech/say service with text message to check the configured language.