:orphan:

oscilloscope
------------


Sample microphone and display input signal in realtime

.. raw:: html

  <video width="558" height="558" controls autoplay>
    <source src="../_static/examples/oscilloscope.mov" type="video/mp4">
    <source src="../_static/examples/oscilloscope.ogg" type="video/ogg">
  </video>

----

.. code-block:: python
    
    
    
    import pyaudio
    import numpy as np
    from gr.pygr import *
    
    FS = 44100  # Sampling frequency
    SAMPLES = 1000
    
    mic = None
    
    
    def get_audio_data():
        global mic
        if mic is None:
            pa = pyaudio.PyAudio()
            mic = pa.open(format=pyaudio.paInt16, channels=1, rate=FS,
                          input=True, frames_per_buffer=SAMPLES)
        amplitudes = np.frombuffer(mic.read(SAMPLES), dtype=np.int16)
        return amplitudes / 32768.
    
    
    start = time.time()
    
    while time.time() - start < 10:
        try:
            amplitudes = get_audio_data()
        except (IOError):
            continue
        plot(range(SAMPLES), amplitudes, xlim=(0, SAMPLES), ylim=(-1, 1))