# -*- coding: utf-8 -*-
"""
Created on Thu Feb 16 11:34:20 2017

@author: lbnc
"""
import numpy as np
import pyaudio
import matplotlib.pyplot as plt

# sampling frequency
fs = 44100 # in Hertz

# frequency of tone
ft = 440 # in Hertz

# duration of sound
duration = 2 # in seconds

# sampling period
dt = 1/fs # in seconds

# number of points
ns = duration*fs

# time
ts = np.arange(ns)*dt

# setup waveform
chA = np.zeros( ns )
chA += np.sin( 2.*np.pi*ft*ts )

plt.plot(ts*1e3, chA)
plt.xlim(0,10)
plt.xlabel('tid ['+r'$\mu$'+'s]')
plt.ylabel('amplitude')

# convert to int16
chA = np.int16( ( 2**15 - 10 )*chA/np.amax(np.abs(chA)) )

# instantiate PyAudio (1)
p = pyaudio.PyAudio()

# open stream (2), 2 is size in bytes of int16
stream = p.open(format=p.get_format_from_width(2),
                channels=1,
                rate=fs,
                output=True)

# play stream (3), blocking call
stream.write(chA)

# stop stream (4)
stream.stop_stream()
stream.close()

# close PyAudio (5)
p.terminate()