start penna zip

serial_helpers.py

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+from matplotlib import pyplot as plt
+import numpy as np
+
+VREFINT_CAL = 24175 # internal calibration value (Vref measured with precise 3.3v reference voltage)
+VREF_CAL    = 3.306 # [Volts] rough estimate from the internal calibration data from factory
+
+TEMP_30_CAL  = 12406
+TEMP_110_CAL = 16472
+
+def vrefint_conv_plot(numbers):
+    '''
+    convert ADC 16bit numbers to tension and evaluate internal reference voltage correction
+    then plot the data
+    '''
+    N_MEAS = len(numbers)
+    
+    Vref_cal = (3.3*VREFINT_CAL)/np.mean(numbers)
+    print(f'Calibrated reference voltage: {Vref_cal:.5f} V')
+    print(f'Vref interno (calibrato): {(VREFINT_CAL*3.3)/2**16:.3f} V')
+    # convert ADC read to voltage
+    volts = [i*(Vref_cal/(2**16-1)) for i in numbers]
+    mean = np.mean(volts)
+    # plot the result (both the single points and the curve connecting them)
+    x_coords = range(0,N_MEAS)
+    plt.plot(x_coords, volts, linewidth='0.8', color='orange', label='result')
+    plt.scatter(x_coords, volts, marker='+', color='orange')
+    plt.hlines(mean, 0, N_MEAS, label=f'mean - {mean:.3f}V')
+
+    plt.legend()
+    plt.grid(True)
+    plt.show()
+
+
+def temp_conv_plot(numbers):
+    '''
+    convert ADC 16bit numbers to temperature and plot the data
+    '''
+    slope = ((110-30)/(TEMP_110_CAL-TEMP_30_CAL))*1000
+    N_MEAS = len(numbers)
+
+    temps = [i*(VREF_CAL/2**16)*slope for i in numbers]
+    mean = np.mean(temps)
+    # plot the result (both the single points and the curve connecting them)
+    x_coords = range(0,N_MEAS)
+    plt.plot(x_coords, temps, linewidth='0.8', color='orange', label='result')
+    plt.scatter(x_coords, temps, marker='+', color='orange')
+    plt.hlines(mean, 0, N_MEAS, label=f'mean - {mean:.3f}℃')
+
+    plt.legend()
+    plt.grid(True)
+    plt.show()
+
+
+def generic_plot(numbers, begin, SAMPLE_TIME):
+    N_MEAS = len(numbers)
+    # convert ADC read to voltage
+    volts = [i*(VREF_CAL/(2**16-1)) for i in numbers]
+    mean = np.mean(volts)
+    # plot the result (both the single points and the curve connecting them)
+    x_coords = np.linspace(0, (N_MEAS+1)*SAMPLE_TIME, N_MEAS)
+
+    plt.plot(x_coords, volts, linewidth='0.8', color='orange', label='result')
+    plt.scatter(x_coords, volts, marker='+', color='orange')
+    #plt.hlines(mean, 0, N_MEAS*SAMPLE_TIME, label=f'mean - {mean:.3f}V')
+    plt.vlines(30*SAMPLE_TIME, min(volts), max(volts))   # trigger point
+    plt.legend()
+    plt.grid(True)
+    plt.show()