190 lines
5 KiB
Python
Executable file
190 lines
5 KiB
Python
Executable file
#!/usr/bin/env python3
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import pyvisa
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import time
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import pyaudio as pa
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import numpy as np
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import scipy as sc
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import matplotlib.pyplot as plt
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current_phase = 0.0
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normalized_f = 0.0 # in cycles per sample : f = normalized_f * f_sampling
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trans_len = 2000
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intro = 0.5 * (1 - np.cos(2 * np.linspace(0, np.pi/2, trans_len)))
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outro = 0.5 * (1 + np.cos(2 * np.linspace(0, np.pi/2, trans_len)))
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intro = np.append(intro, np.ones(1024))
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outro = np.append(outro, np.zeros(1024))
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change_f = True
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trans_done = False
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new_f = 0.0
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fade_time = 0
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def audio_callback(in_data, frame_count, time_info, status):
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global fade_time
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global change_f
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global new_f
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global current_phase
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global normalized_f
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global trans_done
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if change_f == True:
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change_f = False
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trans_done = False
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fade_time = 0
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if(fade_time != 2*trans_len):
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if(fade_time < trans_len):
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last_fade = fade_time + frame_count
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envelope = outro[fade_time:last_fade]
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fade_time = min(last_fade, trans_len)
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elif(fade_time >= trans_len and fade_time < 2*trans_len):
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normalized_f = new_f
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if(new_f == 0):
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current_phase = 0. # Avoid weird sub-audio behavior
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last_fade = fade_time + frame_count
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envelope = intro[fade_time - trans_len:last_fade - trans_len]
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fade_time = min(last_fade, 2*trans_len)
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if(fade_time == 2*trans_len):
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trans_done = True
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sine = np.sin(2 * np.pi * (current_phase + np.arange(frame_count)*normalized_f))
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delta = frame_count*normalized_f
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delta -= np.floor(delta)
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if(delta + current_phase > 1):
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current_phase += delta - 1
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else:
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current_phase += delta
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if(fade_time != 2*trans_len):
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sine *= envelope
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return (sine.astype(np.float32).tobytes(), pa.paContinue)
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paudio = pa.PyAudio()
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audio_strm = paudio.open(format=pa.paFloat32,
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channels=1,
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rate=44100,
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output=True,
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input=False,
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stream_callback=audio_callback,
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start=True)
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print(paudio.get_default_output_device_info())
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print(audio_strm.is_active())
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def acquire_samples(sc_frequency, oscillo):
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global new_f
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global change_f
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global trans_done
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new_f = sc_frequency
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change_f = True
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while (change_f == True) or (trans_done == False):
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time.sleep(0.05)
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time.sleep(0.2)
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oscillo.write("acquire:state run")
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oscillo.write("data:source CH1")
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input_ch = oscillo.query_binary_values("curve?",datatype="b",container=np.array).astype(np.float64)
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oscillo.write("data:source CH2")
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output_ch = oscillo.query_binary_values("curve?",datatype="b",container=np.array).astype(np.float64)
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return input_ch, output_ch
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def manage_measures(f_list, oscillo): # These are NOT normalized frequencies
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hscales = [0.25, 100e-3, 50e-3, 25e-3, 10e-3, 5e-3, 2.5e-3, 1e-3, 500e-6, 250e-6, 100e-6, 50e-6, 25e-6, 10e-6]
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hscales_str = ["2.5e-1", "1.0e-1", "5.0e-2", "2.5e-2", "1.0e-2", "5.0e-3", "2.5e-3", "1.0e-3", "5.0e-4", "2.5e-4", "1.0e-4", "5.0e-5", "2.5e-5", "1.0e-5"]
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hscale_index = 0
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current_hscale = hscales[hscale_index]
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cal_A = []
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cal_B = []
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cal_done = False
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H = []
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W = sc.signal.windows.flattop(2500)
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for f in f_list:
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sc_frequency = np.round(2**20/44100 * f)/2**20
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num_periods = f * 10 * current_hscale
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while(num_periods >= 5 * 2.5):
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hscale_index += 1
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current_hscale = hscales[hscale_index]
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num_periods = f * 10 * current_hscale
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print("horizontal:main:scale " + hscales_str[hscale_index])
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oscillo.write("horizontal:main:scale " + hscales_str[hscale_index])
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cal_done = False
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print(f, " : ", current_hscale,"s/div, ", num_periods, " periods")
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A, B = acquire_samples(sc_frequency, oscillo)
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if not cal_done:
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cal_A, cal_B = acquire_samples(0., oscillo)
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cal_done = True
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print(A)
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print(B)
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A, B = (A - cal_A)*W, (B - cal_B)*W
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f_acq = 250./current_hscale
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rel_f = f / f_acq
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# Obtain the Fourier transforms of A, B @ rel_f, with flattop windowing
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V = np.exp(-2.0j * np.pi * np.arange(2500) * rel_f)
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h = np.sum(B*V)/np.sum(A*V)
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print("H(", f, ") = ", h)
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H.append(h)
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return H
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def find_oscillo():
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rm = pyvisa.ResourceManager()
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R = rm.list_resources()
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print(R)
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# if R.empty():
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# print("No device found")
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# exit(1)
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return rm.open_resource(R[0])
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osci = find_oscillo()
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osci.timeout = 10000
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print(osci.query("*IDN?"))
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osci.write("*RST")
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time.sleep(10)
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osci.write("ch1:scale 2.5e-1")
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osci.write("ch1:bandwidth ON")
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osci.write("ch1:coupling AC")
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osci.write("select:ch1 1")
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osci.write("ch2:scale 2.5e-1")
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osci.write("ch2:bandwidth ON")
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osci.write("ch2:coupling AC")
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osci.write("select:ch2 1")
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osci.write("trigger:main:edge:source LINE")
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osci.write("trigger:main:mode NORMAL")
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osci.write("trigger:main:type EDGE")
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osci.write("acquire:mode sample")
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osci.write("acquire:stopafter sequence")
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osci.write("data:encdg RIBinary")
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decade = [1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2]
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X = [68., 82] + list(np.array(decade)*([100.]*len(decade))) + list(np.array(decade) * ([1000.]*len(decade))) + [1e4, 1.2e4, 1.5e4, 1.8e4]
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H = manage_measures(X, osci)
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Y = 20 * np.log10(np.abs(H))
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fig, axes = plt.subplots(nrows = 2, ncols=1, sharex = True)
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axes[0].semilogx(X,Y)
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axes[0].grid()
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axes[1].semilogx(X, np.angle(H, deg=True))
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axes[1].grid()
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plt.show()
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