peppyalsa ALSA plugin should be installed in order to make PeppyMeter functional.
The following command should be executed in terminal to install PeppyMeter (assuming Raspbian OS and current folder /home/pi):
> git clone https://github.com/project-owner/PeppyMeter.git
Pygame library is the only dependency of PeppyMeter. This library is pre-installed on some OSs. To check if Pygame is installed on your machine start Python interpreter and run the following command in the interpreter:
> import pygame
If you don't see any import exceptions that means that Pygame is installed on your machine. If you see exception you have to install Pygame:
sudo apt-get install python3-pygame