ADC_Record_Graph | Python Fiddle

#matplotlib and read/write aquisition
import Queue
import datetime as DT
import collections
import matplotlib.pyplot as plt
import numpy as np
import multiprocessing as mp
import time
import datetime
import os
import matplotlib.dates as mdates
import matplotlib.animation as animation
#ADC
from ABE_DeltaSigmaPi import DeltaSigma 
from ABE_helpers import ABEHelpers
#PyQt
from PyQt4 import QtGui, QtCore 
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas

#ADC INFO
import sys
i2c_helper = ABEHelpers() 
bus = i2c_helper.get_smbus() 
adc = DeltaSigma(bus, 0x68, 0x69, 18)

#Rename file to date
base_dir = '/home/pi/Desktop/DATA'
ts = time.time()
filename_time = datetime.datetime.fromtimestamp(ts).strftime('%Y-%m-%d')
filename_base = os.path.join(base_dir, filename_time)
filename = '%s.txt' % filename_base

# you will want to change read_delay to 5000
read_delay = int(5000)    # in milliseconds 
write_delay = read_delay/1000.0  # in seconds 
window_size = 60
nlines = 8
datenums = collections.deque(maxlen=window_size)
ys = [collections.deque(maxlen=window_size) for i in range(nlines)]

#PyQt window to display readings
try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_mplMainWindow(object):
    def setupUi(self, mplMainWindow):
        mplMainWindow.setObjectName(_fromUtf8("mplMainWindow"))
        mplMainWindow.resize(800, 380)
        self.centralwidget = QtGui.QWidget(mplMainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.horizontalLayoutWidget = QtGui.QWidget(self.centralwidget)
        self.horizontalLayoutWidget.setGeometry(QtCore.QRect(30, 10, 751, 352))
        self.horizontalLayoutWidget.setObjectName(_fromUtf8("horizontalLayoutWidget"))
        self.horizontalLayout = QtGui.QHBoxLayout(self.horizontalLayoutWidget)
        self.horizontalLayout.setMargin(0)
        self.horizontalLayout.setObjectName(_fromUtf8("horizontalLayout"))
        self.widget = QtGui.QWidget(self.horizontalLayoutWidget)
        self.widget.setEnabled(True)
        self.widget.setMinimumSize(QtCore.QSize(500, 300))
        self.widget.setMaximumSize(QtCore.QSize(500, 300))
        self.horizontalLayout.addWidget(self.widget)
        self.verticalLayout = QtGui.QVBoxLayout()
        self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
        self.label = QtGui.QLabel(self.horizontalLayoutWidget)
        self.label.setMaximumSize(QtCore.QSize(100, 30))
        self.label.setObjectName(_fromUtf8("label"))
        self.verticalLayout.addWidget(self.label)
        self.lineEdit = QtGui.QLineEdit(self.horizontalLayoutWidget)
        self.lineEdit.setMinimumSize(QtCore.QSize(20, 20))
        self.lineEdit.setMaximumSize(QtCore.QSize(100, 25))
        self.lineEdit.setObjectName(_fromUtf8("lineEdit"))
        self.verticalLayout.addWidget(self.lineEdit)
        self.label_2 = QtGui.QLabel(self.horizontalLayoutWidget)
        self.label_2.setMaximumSize(QtCore.QSize(100, 30))
        self.label_2.setObjectName(_fromUtf8("label_2"))
        self.verticalLayout.addWidget(self.label_2)
        self.lineEdit_2 = QtGui.QLineEdit(self.horizontalLayoutWidget)
        self.lineEdit_2.setMinimumSize(QtCore.QSize(20, 20))
        self.lineEdit_2.setMaximumSize(QtCore.QSize(100, 25))
        self.lineEdit_2.setObjectName(_fromUtf8("lineEdit_2"))
        self.verticalLayout.addWidget(self.lineEdit_2)
        self.label_3 = QtGui.QLabel(self.horizontalLayoutWidget)
        self.label_3.setMaximumSize(QtCore.QSize(100, 30))
        self.label_3.setObjectName(_fromUtf8("label_3"))
        self.verticalLayout.addWidget(self.label_3)
        self.lineEdit_3 = QtGui.QLineEdit(self.horizontalLayoutWidget)
        self.lineEdit_3.setMinimumSize(QtCore.QSize(20, 20))
        self.lineEdit_3.setMaximumSize(QtCore.QSize(100, 25))
        self.lineEdit_3.setObjectName(_fromUtf8("lineEdit_3"))
        self.verticalLayout.addWidget(self.lineEdit_3)
        self.label_4 = QtGui.QLabel(self.horizontalLayoutWidget)
        self.label_4.setMaximumSize(QtCore.QSize(100, 30))
        self.label_4.setObjectName(_fromUtf8("label_4"))
        self.verticalLayout.addWidget(self.label_4)
        self.lineEdit_4 = QtGui.QLineEdit(self.horizontalLayoutWidget)
        self.lineEdit_4.setMinimumSize(QtCore.QSize(20, 20))
        self.lineEdit_4.setMaximumSize(QtCore.QSize(100, 25))
        self.lineEdit_4.setObjectName(_fromUtf8("lineEdit_4"))
        self.verticalLayout.addWidget(self.lineEdit_4)
        self.horizontalLayout.addLayout(self.verticalLayout)
        self.verticalLayout_2 = QtGui.QVBoxLayout()
        self.verticalLayout_2.setObjectName(_fromUtf8("verticalLayout_2"))
        self.label_5 = QtGui.QLabel(self.horizontalLayoutWidget)
        self.label_5.setMaximumSize(QtCore.QSize(100, 30))
        self.label_5.setObjectName(_fromUtf8("label_5"))
        self.verticalLayout_2.addWidget(self.label_5)
        self.lineEdit_5 = QtGui.QLineEdit(self.horizontalLayoutWidget)
        self.lineEdit_5.setMinimumSize(QtCore.QSize(100, 20))
        self.lineEdit_5.setMaximumSize(QtCore.QSize(100, 25))
        self.lineEdit_5.setObjectName(_fromUtf8("lineEdit_5"))
        self.verticalLayout_2.addWidget(self.lineEdit_5)
        self.label_6 = QtGui.QLabel(self.horizontalLayoutWidget)
        self.label_6.setMaximumSize(QtCore.QSize(100, 30))
        self.label_6.setObjectName(_fromUtf8("label_6"))
        self.verticalLayout_2.addWidget(self.label_6)
        self.lineEdit_6 = QtGui.QLineEdit(self.horizontalLayoutWidget)
        self.lineEdit_6.setMinimumSize(QtCore.QSize(100, 20))
        self.lineEdit_6.setMaximumSize(QtCore.QSize(100, 25))
        self.lineEdit_6.setObjectName(_fromUtf8("lineEdit_6"))
        self.verticalLayout_2.addWidget(self.lineEdit_6)
        self.label_7 = QtGui.QLabel(self.horizontalLayoutWidget)
        self.label_7.setMaximumSize(QtCore.QSize(100, 30))
        self.label_7.setObjectName(_fromUtf8("label_7"))
        self.verticalLayout_2.addWidget(self.label_7)
        self.lineEdit_7 = QtGui.QLineEdit(self.horizontalLayoutWidget)
        self.lineEdit_7.setMinimumSize(QtCore.QSize(100, 20))
        self.lineEdit_7.setMaximumSize(QtCore.QSize(100, 25))
        self.lineEdit_7.setObjectName(_fromUtf8("lineEdit_7"))
        self.verticalLayout_2.addWidget(self.lineEdit_7)
        self.label_8 = QtGui.QLabel(self.horizontalLayoutWidget)
        self.label_8.setMaximumSize(QtCore.QSize(100, 30))
        self.label_8.setObjectName(_fromUtf8("label_8"))
        self.verticalLayout_2.addWidget(self.label_8)
        self.lineEdit_8 = QtGui.QLineEdit(self.horizontalLayoutWidget)
        self.lineEdit_8.setMinimumSize(QtCore.QSize(100, 20))
        self.lineEdit_8.setMaximumSize(QtCore.QSize(100, 25))
        self.lineEdit_8.setObjectName(_fromUtf8("lineEdit_8"))
        self.verticalLayout_2.addWidget(self.lineEdit_8)
        self.horizontalLayout.addLayout(self.verticalLayout_2)
        mplMainWindow.setCentralWidget(self.centralwidget)

self.retranslateUi(mplMainWindow)
        QtCore.QMetaObject.connectSlotsByName(mplMainWindow)

def retranslateUi(self, mplMainWindow):
        mplMainWindow.setWindowTitle(_translate("mplMainWindow", "Real Time Data Acquisition", None))
        self.widget.setWhatsThis(_translate("mplMainWindow", "<html><head/><body><p>matplotlib</p></body></html>", None))
        self.label.setText(_translate("mplMainWindow", "Channel 1:", None))
        self.label_2.setText(_translate("mplMainWindow", "Channel 2:", None))
        self.label_3.setText(_translate("mplMainWindow", "Channel 3:", None))
        self.label_4.setText(_translate("mplMainWindow", "Channel 4:", None))
        self.label_5.setText(_translate("mplMainWindow", "Channel 5:", None))
        self.label_6.setText(_translate("mplMainWindow", "Channel 6:", None))
        self.label_7.setText(_translate("mplMainWindow", "Channel 7:", None))
        self.label_8.setText(_translate("mplMainWindow", "Channel 8:", None))

def animate(i, queue):
    try:
        row = queue.get_nowait()
    except Queue.Empty:
        return
    datenums.append(mdates.date2num(row[0]))
    for i, y in enumerate(row[1:]):
        ys[i].append(y)
    for i, y in enumerate(ys):
        lines[i].set_data(datenums, y)
    ymin = min(min(y) for y in ys)
    ymax = max(max(y) for y in ys)
    xmin = min(datenums)
    xmax = max(datenums)
    if xmin < xmax:
        ax.set_xlim(xmin, xmax)
    ax.set_ylim(ymin, ymax)
    fig.canvas.draw()

def write_data(filename, queue):
    while True:
        delay1 = DT.datetime.now()
        row = []
        for i in range(nlines):
            # read from adc channels and print to screen
            channel = adc.read_voltage(i)
            row.append(channel)

queue.put([delay1]+row)

#print voltage variables to local file
        with open(filename, 'a') as DAQrecording:
            time1 = delay1.strftime('%Y-%m-%d')
            time2 = delay1.strftime('%H:%M:%S')
            row = [time1, time2] + row
            row = map(str, row)
            DAQrecording.write('{}\n'.format(', '.join(row)))

#Delay until next 5 second interval
        delay2 = DT.datetime.now()
        difference = (delay2 - delay1).total_seconds()
        time.sleep(write_delay - difference)

def main():    
    global fig, ax, lines
    queue = mp.Queue()
    proc = mp.Process(target=write_data, args=(filename, queue))
    # terminate proc when main process ends
    proc.daemon = True
    # spawn the writer in a separate process
    proc.start()

fig, ax = plt.subplots()
    xfmt = mdates.DateFormatter('%H:%M:%S')
    ax.xaxis.set_major_formatter(xfmt)
    # make matplotlib treat x-axis as times
    ax.xaxis_date()

fig.autofmt_xdate(rotation=25)

lines = []
    for i in range(nlines):
        line, = ax.plot([], [])
        lines.append(line)

ani = animation.FuncAnimation(fig, animate, interval=read_delay, fargs=(queue,))
    
    app = QtGui.QApplication(sys.argv)
    win = Ui_mplMainWindow()
    win.show()

sys.exit(app.exec_())

if __name__ == '__main__':
    main()

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