Text-to-Speech Speaking Robot using Raspberry Pi 4

Overview

In this project, we will make a Text-to-Speech Speaking Robot using Raspberry Pi & HAT Module. For this, we will use a Robotic Car Kit called Picar-X Robot from Sunfounder.

The PiCar-X is an AI self-driving robot car that uses Raspberry Pi as its control center. The Robotic Kit is designed by SunFounder. The Kit comes with a Robot HAT for Raspberry Pi. The HAT integrates the motor driving, servo driving, and preset ADC, PWM, and digital pins to extend the functionality. The PiCar-X’s has a 2-axis camera module, ultrasonic module, and line tracking modules that can provide the functions of color/face/traffic signs detection, automatic obstacle avoidance, automatic line tracking, etc.

To make the Raspberry Pi speak and read some text aloud, we need a software interface to convert text to speech on the speakers. For this, we need a Text To Speech engine. The TTS engine we are using in this tutorial is eSpeak. The voice may be a little robotic, however, it runs offline which is an added plus. This example only shows the Text-to-Speech output however you can combine this script with the Line follower Robot or may be Obstacle Avoidance Robot and make Raspberry Pi speak what you want.

Bill of Materials

We need the following components along with the SunFounder Robot Car Kit to make a Text-to-Speech Speaking Robot using Raspberry Pi. You can purchase all these components from Amazon links:

S.N.	Components	Quantity	Purchase Links
1	Raspberry Pi Ai Car Kit PiCar-X	1	Amazon \| SunFounder
2	Raspberry Pi 4	1	Amazon \| SunFounder
3	Samsung 18650 Battery	2	AliExpress
4	SD Card 16/32 GB	1	Amazon \| SunFounder
5	SD Card Adapter	1	Amazon \| AliExpress
6	18650 Battery Charger	1	Amazon \| AliExpress

Robot HAT cannot charge the battery, so you need to buy a battery charger at the same time.

Robot Assembly

The Sunfounder Picar-X Robot Kit comes with all the necessary components required for the Robot which include the following components. You need to buy a Raspberry Pi 4 Board and a pair of Samsung 18650 Batteries separately.

The most important part of this Kit is Robot HAT. With the Robot HAT board, the PiCar-X integrates left/right driving motors, servo motors for steering, and the camera’s pan/tilt functions, and pre-sets the Robot HAT’s ADC, PWM, and Digital I2C pins to allow for extensions to the standard functionality of the Raspberry Pi.

Both a speaker and a Bluetooth chip have been engineered into the Robot HAT for remote control of Text-to-Speech, sound effects, or even background music functionality.

To assemble the components together and make a perfect Robotic Car you can follow the Assembly Guide. The PDF Document has all the images and a pictorial view for easy help with assembly.

The Robotic Kit Part details, Assembly guide, HAT parts & functionality, calibration process, Robot Testing and Setting Up Rasbian OS has been explained in PiCar-X Getting Started guide.

Read the tutorial thoroughly to understand the Hardware & Software Setup Part.

Installing Python Modules & Libraries

The OS installation part and setup part can be followed on Raspberry Pi OS Setup. But for this robotic project part, it is recommended to install Raspberry Pi OS(Legacy).

You can either use the HDMI Screen or enable SSH and connect the Raspberry Pi to VNC Viewer using the local IP Address, username, and password. It is best to connect the Robot Wirelessly via a Remote Desktop as we need a remote control for it.

The Picar-X Robot should be turned ON and Raspberry Pi should be connected to the network. Now let’s install all the Python Modules and libraries.

Let’s first update the system using the following commands.

1 2	sudo apt update sudo apt upgrade

Then install the Python3-related packages.

1	sudo apt install git python3-pip python3-setuptools python3-smbus

Download & install the libraries for Robot-Hat.

cd /home/pi/

git clone https://github.com/sunfounder/robot-hat.git

cd robot-hat

sudo python3 setup.py install

Running ‘setup.py‘ will download some necessary components. Your download may have failed due to network issues. You may need to download it again at this point. See the following interface, type ‘Y‘, and press Enter.

Now, download and install the ;vilib‘ module.

cd /home/pi/

git clone https://github.com/sunfounder/vilib.git

cd vilib

sudo python3 install.py

Similarly download and install the ‘picar-x‘ module.

cd /home/pi/

git clone -b v2.0 https://github.com/sunfounder/picar-x.git

cd picar-x

sudo python3 setup.py install

This will download a large number of files, therefore it will take time.

Once the download is complete, run the ‘i2samp.sh‘ script to install the components required by the i2s amplifier, otherwise the picar-x will have no sound.

1 2	cd /home/pi/picar-x sudo bash i2samp.sh

Type ‘y‘ and press enter to continue running the script.

Type ‘y‘ and press enter to run ‘/dev/zero‘ in the background.

Type y and press enter to restart the Picar-X.

After restarting, the Raspberry Pi will connect to the Network and will play a sound.

If there is no sound after restarting, you may need to run the ‘i2samp.sh‘ script several times.

All the installation and setup part is complete here.

Python Code for Text-to-Speech Speaking Robot

Here is a complete Python Code for Line Text-to-Speech Speaking Robot using Raspberry Pi 4 & HAT.

You can directly run the code from the terminal using the following command.

1 2	cd /home/pi/picar-x sudo bash i2samp.sh

There will be several prompts asking to confirm the request. Respond to all prompts with a Y. After the changes have been made to the Raspberry Pi system, the computer will need to reboot for these changes to take effect.

After rebooting, run the i2samp.sh script again to test the amplifier. If a sound successfully plays from the speaker, the configuration is complete.

The code is also located in the source code path ‘picar-x/example/tts_example.py‘. You can directly open the code from this location. You can Modify/Reset/Copy/Run/Stop the code below.

from robot_hat import TTS

if __name__ == "__main__":

words = ["Hello", "Hi", "Good bye", "Nice to meet you"]

tts_robot = TTS()

for i in words:

print(i)

tts_robot.say(i)

Code Explanation

The eSpeak software is used to implement the functions of TTS.

Import the TTS module in robot_hat, which encapsulates functions that convert text to speech.

1	from robot_hat import TTS

Create a string list words , then create an instantiated object of the TTS() class tts_robot , and finally, use the tts_robot.say() function to speak the words in the list in speech.