Audio Input and Output from USB Microphone + Raspberry Pi

Overview
This tutorial will describe how to input audio to a Raspberry Pi using a USB microphone and furthermore how to output that audio simultaneously if needed.
Materials and Prerequisites

• USB Microphone
• Raspberry Pi

Process
Install the following libraries:
PyAudio: Used to play and record audio on a variety of platforms. Install it by typing pip install pyaudio into the terminal
Numpy: fundamental package for scientific computing in Python. Install it by typing pip install numpy into the terminal

Copy the following Python script to read audio input to wave files:
Copy the following Python script for simultaneously streaming audio output with input:

import pyaudio
import numpy as np

chunk=4096
RATE=44100

p=pyaudio.PyAudio()

#input stream setup
stream=p.open(format = pyaudio.paInt16,rate=RATE,channels=1, input_device_index = 2, input=True, frames_per_buffer=chunk)

#output stream setup
player=p.open(format = pyaudio.paInt16,rate=RATE,channels=1, output=True, frames_per_buffer=chunk)

while True:            #Used to continuously stream audio
     data=np.fromstring(stream.read(chunk,exception_on_overflow = False),dtype=np.int16)
     player.write(data,chunk)
    
#closes streams
stream.stop_stream()
stream.close()
p.terminate

Authors
Pavan Narahari - Fall 2018
Sam Manyak - Fall 2018
Group Link
Crutooth
References
The basis of the code was derived from the code developed by markjay4k, an engineer working with audio spectrum analyzers. You can find a link to his github at: https://github.com/markjay4k/Audio-Spectrum-Analyzer-in-Python
Here is the documentation for the PyAudio Library: PyAudio