plot_data.py

import serial # pip install pyserial
import csv
import numpy as np
import pandas as pd
from datetime import datetime
import time
import matplotlib.pyplot as plt

ser = serial.Serial('/dev/ttyACM0', 115200)  
timestamp = datetime.now().strftime("%m-%d-%H-%M-%S")
filename = f"data/data_log_{timestamp}.csv"

headers = ["SETPOINT_RPM", "SETPOINT_POS", "MEASUREMENT_RPM", "MEASUREMENT_POS"]

file_1 = open(filename, mode='w', newline='')
writer_1 = csv.writer(file_1, delimiter=';')
writer_1.writerow(headers)
try:
    while True:
        if ser.in_waiting > 0:
            line = ser.readline().decode('utf-8').strip() 
            data_fields = line.split(';') 
                        
            if len(data_fields) == len(headers):  
                writer_1.writerow(data_fields)
except KeyboardInterrupt:
    file_1.close()
    df1 = pd.read_csv(filename, sep=';')

    timestamp = datetime.now().strftime("%m-%d-%H-%M-%S")
    filename = f"plot/plot_{timestamp}.png"

    _, axs = plt.subplots(2, 1, figsize=(8, 8))
    Kp_speed = 0.6
    Ki_speed = 1.0
    Kp_pos = 0.4
    Ki_pos = 0.0

    plt.sca(axs[0])
    ax = df1['MEASUREMENT_POS'].plot()
    df1['SETPOINT_POS'].plot(ax=ax, linestyle = '--')


    plt.title(f'Position Kp={Kp_pos}, Ki={Ki_pos}')
    plt.grid(color = 'green', linestyle = '--', linewidth = 0.5)

    plt.sca(axs[1])
    plt.title(f'Velocity Kp={Kp_speed}, Ki={Ki_speed}')
    ax = df1['MEASUREMENT_RPM'].plot()
    df1['SETPOINT_RPM'].plot(ax=ax, linestyle = '--')
    plt.grid(color = 'green', linestyle = '--', linewidth = 0.5)

    plt.savefig(filename)
    print('Save csv and png!')