Plotting With Pyqtgraph Using External Data

I'm trying to plot data of diferentes sensors en realtime,so I decided to plot the data using PyQtGraph in PyQt, in order to make it work with several sensor's data from differnt

Solution 1:

Instead of using MultiProcessing you should use MultiThreading, that is, create threads that are responsible for collecting data (in your example emulate data) and then send the data to the GUI by signals.

PlotData.py

from pyqtgraph.Qt import QtGui, QtCore
import numpy as np
import pyqtgraph as pg
import sys

class Plot2D(pg.GraphicsWindow):
    def __init__(self):
        pg.GraphicsWindow.__init__(self, title="Dibujar")
        self.traces = dict()
        self.resize(1000, 600)
        pg.setConfigOptions(antialias=True)
        #self.canvas = self.win.addPlot(title="Pytelemetry")
        self.waveform1 = self.addPlot(title='WAVEFORM1', row=1, col=1)
        self.waveform2 = self.addPlot(title='WAVEFORM2', row=2, col=1)

    def set_plotdata(self, name, x, y):
        if name in self.traces:
            self.traces[name].setData(x, y)
        else:
            if name == "910D":
                self.traces[name] = self.waveform1.plot(x, y, pen='y', width=3)
            elif name == "MPU":
                self.traces[name] = self.waveform2.plot(x, y, pen='y', width=3)

    @QtCore.pyqtSlot(str, tuple)
    def updateData(self, name, ptm):
        x, y = ptm
        self.set_plotdata(name, x, y)

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    plot = Plot2D()
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()

main.py

import sys

from pyqtgraph.Qt import QtCore, QtGui
import threading
import numpy as np
import time

from PlotData import Plot2D

class Helper(QtCore.QObject):
    changedSignal = QtCore.pyqtSignal(str, tuple)

def create_data1(helper, name):
    t = np.arange(-3.0, 2.0, 0.01)
    i = 0.0
    while True:
        s = np.sin(2 * 2 * 3.1416 * t) / (2 * 3.1416 * t + i)
        time.sleep(.1)
        helper.changedSignal.emit(name, (t, s))
        i = i + 0.1

def create_data2(helper, name):
    t = np.arange(-3.0, 2.0, 0.01)
    i = 0.0
    while True:
        s = np.cos(2 * 2 * 3.1416 * t) / (2 * 3.1416 * t - i)
        time.sleep(.1)
        helper.changedSignal.emit(name, (t, s))
        i = i + 0.1

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    helper = Helper()
    plot = Plot2D()
    helper.changedSignal.connect(plot.updateData, QtCore.Qt.QueuedConnection)
    threading.Thread(target=create_data1, args=(helper, "910D"), daemon=True).start()
    threading.Thread(target=create_data2, args=(helper, "MPU"), daemon=True).start()
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()