Arduino controller with temperature sensor and Python interface for dynamic identification of control objects

Introduction

Temperature measurement circuit

Measuring subsystem

#include <OneWire.h> // OneWire DS18B20 Temperature Example // http://www.pjrc.com/teensy/td_libs_OneWire.html // The DallasTemperature library can do all this work for you! // http://milesburton.com/Dallas_Temperature_Control_Library // Data  DS18B20   7-  // Arduino OneWire ds(7); void setup(void) { Serial.begin(9600); } void loop(void) { byte i; byte present = 0; byte type_s = 0; byte data[12]; byte addr[8]; float celsius; ds.search(addr); ds.reset(); ds.select(addr); ds.write(0x44, 1); delay(800); present = ds.reset(); ds.select(addr); ds.write(0xBE); // Read Scratchpad for ( i = 0; i < 9; i++) { data[i] = ds.read(); } int16_t raw = (data[1] << 8) | data[0]; celsius = (float)raw / 16.0; Serial.println(celsius); } 

Python interface for processing the “acceleration curve” and its graphical implementation

1. Management and polling of virtual COM port via USB port; it uses the functions of the pySerial library.
2. Interactive interaction with the operator; Here we enter the required number of measurements and the serial port number (we look in the Device Manager of MS Windows). If the port number is entered correctly and is not occupied by other programs, the current measured values ​​of the technological parameter are displayed on the console and in the graphic window. At the end of the measurements, the console displays the duration of the measurement time, the sensor polling period and the indication in which txt file the table with measurement results is located, and the graph window displays the measurement graph, date, time, experiment number, sensor polling period.
3. Automatic registration of measurement results; here on the disk in the folder with the script, you must have a file count.txt, which contains an integer without a signed number, used as an experiment counter; each subsequent experiment increases the counter by one and adds the value of the counter to the name of the file with the table of experiment results.

 import numpy as np import matplotlib.pyplot as plt import serial from drawnow import drawnow import datetime, time #     def cur_graf(): plt.title("DS18B20") plt.ylim( 20, 40 ) plt.plot(nw, lw1, "r.-") plt.ylabel(r'$, \degree $') plt.xlabel(r'$ \ $') plt.grid(True) #      def all_graf(): plt.close() plt.figure() plt.title("DS18B20\n" + str(count_v) + "-  " + "(" + now.strftime("%d-%m-%Y %H:%M") + ")") plt.plot( n, l1, "r-") plt.ylabel(r'$, \degree $') plt.xlabel(r'$ \ $' + '; (  : {:.6f}, c)'.format(Ts)) plt.grid(True) plt.show() #   #    str_m = input("  : ") m = eval(str_m) #    mw = 16 #    ser = serial.Serial() ser.baudrate = 9600 port_num = input("   : ") ser.port = 'COM' + port_num ser #   try: ser.open() ser.is_open print(" : " + ser.portstr) except serial.SerialException: print("   : " + ser.portstr) raise SystemExit(1) #  l1 = [] #    t1 = [] lw1 = [] #     n = [] #     nw = [] #      #      filename = 'count.txt' in_file = open(filename,"r") count = in_file.read() count_v = eval(count) + 1 in_file.close() in_file = open(filename,"w") count = str(count_v) in_file.write(count) in_file.close() filename = count + '_' + filename out_file = open(filename,"w") #      print("\n :\n") print("n -  ;") print("T - , . ;") print("\n    \n") print('{0}{1}\n'.format('n'.rjust(4),'T'.rjust(10))) #     #  #   #       i = 0 while i < m: n.append(i) nw.append(n[i]) if i >= mw: nw.pop(0) line1 = ser.readline().decode('utf-8')[:-2] t1.append(time.time()) if line1: l1.append(eval(line1)) lw1.append(l1[i]) if i >= mw: lw1.pop(0) print('{0:4d} {1:10.2f}'.format(n[i],l1[i])) drawnow(cur_graf) i += 1 #   ser.close() ser.is_open #time_tm -= time_t0 time_tm = t1[m - 1] - t1[0] print("\n   : {0:.3f}, c".format(time_tm)) Ts = time_tm / (m - 1) print("\n   : {0:.6f}, c".format(Ts)) #    print("\n     {}\n".format(filename)) for i in np.arange(0,len(n),1): count = str(n[i]) + "\t" + str(l1[i]) + "\n" out_file.write(count) #    out_file.close() out_file.closed #    now = datetime.datetime.now() #     all_graf() end = input("\n  Ctrl-C,   ") 

Python interface to obtain the transfer function and assess the adequacy of the model

 # -*- coding: utf8 -*- import matplotlib.pyplot as plt import time start = time.time() from scipy.interpolate import splev, splrep import scipy.integrate as spint import numpy as np from scipy.integrate import quad xx =np.array(np.arange(0,230,1)) yy1 =np.array([ 24.87, 25.06, 25.31, 25.5, 25.81, 26.06, 26.37, 26.62, 26.87, 27.12, 27.44, 27.69, 27.87, 28.12, 28.31, 28.56, 28.75, 28.94, 29.12, 29.31, 29.5, 29.69, 29.81, 30.0, 30.12, 30.25, 30.37, 30.56, 30.69, 30.81, 30.87, 31.0, 31.12, 31.25, 31.31, 31.44, 31.5, 31.62, 31.69, 31.81, 31.87, 31.94, 32.06, 32.13, 32.19, 32.25, 32.31, 32.38, 32.44, 32.5, 32.56, 32.63, 32.69, 32.75, 32.75, 32.81, 32.88, 32.94, 32.94, 33.0, 33.06, 33.13, 33.13, 33.19, 33.25, 33.25, 33.31, 33.31, 33.38, 33.38, 33.44, 33.44, 33.5, 33.5, 33.56, 33.56, 33.56, 33.63, 33.63, 33.69, 33.69, 33.69, 33.75, 33.75, 33.81, 33.81, 33.81, 33.88, 33.88, 33.88, 33.88, 33.94, 33.94, 33.94, 34.0, 34.0, 34.0, 34.0, 34.06, 34.06, 34.06, 34.06, 34.06, 34.13, 34.13, 34.13, 34.13, 34.13, 34.19, 34.19, 34.19, 34.19, 34.19, 34.25, 34.25, 34.25, 34.25, 34.25, 34.25, 34.31, 34.31, 34.31, 34.31, 34.31, 34.31, 34.31, 34.38, 34.38, 34.38, 34.38, 34.38, 34.38, 34.38, 34.38, 34.38, 34.44, 34.44, 34.44, 34.44, 34.44, 34.44, 34.44, 34.44, 34.44, 34.5, 34.5, 34.5, 34.5, 34.5, 34.5, 34.5, 34.5, 34.5, 34.5, 34.5, 34.5, 34.5, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.56, 34.63, 34.56, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.63, 34.69, 34.63, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.69, 34.75, 34.69, 34.75, 34.69, 34.69, 34.75, 34.75, 34.75, 34.75, 34.75]) yy2=yy1-24.87#   yy=yy2/max(yy2)# """      """ def h(x): spl = splrep(xx , yy ) return splev(x, spl) """          (6)""" S1=(spint.quad(lambda x:1-h(x),xx[0],xx[len(xx)-1])[0]) S2=(spint.quad(lambda x:(1-h(x))*(S1-x),xx[0],xx[len(xx)-1])[0]) S3=(spint.quad(lambda x:(1-h(x))*(S2-S1*x+(1/2)*x**2),xx[0],xx[len(xx)-1])[0]) S4=(spint.quad(lambda x:(1-h(x))*(S3-S2*x+S1*(1/2)*x**2-(1/6)*x**3),xx[0],xx[len(xx)-1])[0]) """    """ b1=-S4/S3 a1=b1+S1 a2=b1*S1+S2 a3=b1*S2+S3 """    """ def ff(x,t): j=(-1)**0.5 return (2/np.pi)*( ((b1*x*j+1)*np.e**(-25*x)/(a3*(x*j)**3+a2*(x*j)**2+a1*x*j+1)).real)*(np.sin(x*t)/x) y=np.array([round(quad(lambda x: ff(x,t),0, 0.6)[0],2) for t in xx]) """     """ k=round(1-sum([(yy[i]-y[i])**2 for i in np.arange(0,len(yy)-1,1)])/sum([(yy[i])**2 for i in np.arange(0,len(yy)-1,1)]),5) stop = time.time() print ("   :",round(stop-start,3)) plt.title('   .\n  : %s'%k) plt.plot(xx, yy,label='W=(%s*p+1)/(%s*p**3+%s*p**2+%s*p+1)'%(round(b1,1),round(a3,1),round(a2,1),round(a1,1))) plt.legend(loc='best') plt.grid(True) plt.show() 

findings