https://stackoverflow.com/questions/53576928/pyqt5-plotdataitem-for-multiple-live-streams-in-single-plot

main.py

from PyQt5 import QtCore, QtWidgets
import queue
import threading
import pyqtgraph as pg
import numpy as np

class App(QtWidgets.QMainWindow):
    def __init__(self):
        super(App, self).__init__()
        self.initUI()
        # define plots axis and labels
        self.pc1 = pg.PlotDataItem(name="ACC")
        self.pc2 = pg.PlotDataItem(name="ACC2")
        self.pc3 = pg.PlotDataItem(name="ACC3")

        self.pw1.addItem(self.pc1)
        self.pw1.addItem(self.pc2)
        self.pw1.addItem(self.pc3)
        self.pw1.setLabel('left', 'LEFT FOOT ACC', units='m/s^2')
        self.pw1.setLabel('bottom', 'Time', units='s')

        # timer
        self.timer = QtCore.QTimer(self, timeout=self.updateplot)
        self.data_out = []
        self.emulate_data()

    def emulate_data(self):
        self.l_queue = queue.Queue(10)

        def io(q):
            t = 0
            while True:
                r = np.cos(2 * np.pi *t)
                s = np.sin(2 * np.pi *t)
                u = np.exp(-2 * np.pi * t)
                t += 0.01
                q.put([t, r, s, u, r*s])
                QtCore.QThread.msleep(10)
            print("Done")

        t = threading.Thread(target=io, args=(self.l_queue,), daemon=True)
        t.start()

    def initUI(self):
        central_widget = QtWidgets.QWidget()
        self.setCentralWidget(central_widget)
        grid_layout = pg.QtGui.QGridLayout(central_widget)
        # create subplot grid
        self.pw1 = pg.PlotWidget()
        grid_layout.addWidget(self.pw1, 2, 0, 1, 4)

        # create start/stop button
        self.on_start = QtWidgets.QPushButton("START", clicked=self.on_start_clicked)
        self.on_stop = QtWidgets.QPushButton("STOP")
        grid_layout.addWidget(self.on_start,4,0,1,8)
        grid_layout.addWidget(self.on_stop,5,0,1,8)

    def on_start_clicked(self):
        # do something
        if not self.timer.isActive():
            self.timer.timeout.connect(self.updateplot)
            self.timer.start(8)


    def on_stop_clicked(self):
        # do something
        pass

    def updateplot(self):
        while not self.l_queue.empty():
            self.data_out.append(self.l_queue.get())
            if self.data_out:
                self.pc1.setData(np.array(self.data_out)[:,2], pen=(255,0,0))
                self.pc2.setData(np.array(self.data_out)[:,3], pen=(0,255,0))
                self.pc3.setData(np.array(self.data_out)[:,4], pen=(0,0,255))

if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    ex = App()
    ex.show()
    sys.exit(app.exec_())