How can I stream program output to wxpython listctrl?

Question

I'm making project for school, which is temperature measuring platform with raspberry pi and i'm trying it to stream my data continuous into GUI. Please help.

I have a problem with putting output to wxListCtrl. This is my code:

import spidev
import time
import math
from time import strftime
import string
import os

spi = spidev.SpiDev()
spi.open(0, 0)
filename = strftime("%d-%b-%Y %H_%M_%S")

def read_adc(adcnum):
# read SPI data from MCP3304 chip, 8 possible adc's (0 thru 7)
    if adcnum > 7 or adcnum < 0:
        return -1

# Frame format: 0000 1SCC | C000 000 | 000 000
    r = spi.xfer2([((adcnum & 6) >> 1)+12 , (adcnum & 1) << 7, 0])
    adcout = ((r[1] & 15) << 8) + r[2]
    return adcout

def make_sure_path_exists(path):
    try:
        os.makedirs(path)
    except OSError:
        if not os.path.isdir(path):
            raise

def get_temperature(adc):
# read thermistor voltage drop and convert it to degrees of Celsius
    value = read_adc(adc)               #read the adc
    volts = (value * 3.3) / 4095        #calculate the voltage

    # check if the thermistor is connected to this channel
    if volts > 3.2:
        return 0

    ohms = (volts*10000)/(3.3-volts)    #calculate thermistor resistance
    lnohm = math.log1p(ohms)            #take ln(ohms)

    # a, b, & c values from www.rusefi.com/Steinhart-Hart.html
    # 0-50 C
    a =  0.001125256672
    b =  0.0002347204473
    c =  0.00000008563052732

    # Steinhart Hart Equation
    # T = 1/(a + b[ln(ohm)] + c[ln(ohm)]^3)
    t1 = (b*lnohm)                      #b[ln(ohm)]
    c2 = lnohm                          #c[ln(ohm)]
    t2 = c*math.pow(c2,3)               #c[ln(ohm)]^3
    temp = 1/(a + t1 + t2)              #calcualte temperature in K
    tempc = temp - 273.15               #K to C

    #print out info
    #print ("%4d/4095 => %5.4f V => %6.1f ? => %5.2f °K => %3.1f °C from adc     %d" % (value, volts, ohms, temp, tempc, adc))
    print ("%3.1f °C from sensor %d" % (tempc, adc))

    return tempc

make_sure_path_exists("./data")
'''while True:
    #write to log
    log = open("./data/"+filename+'.csv', 'a') #open a text file for logging
    log.write(strftime("%d/%m/%y,%H:%M:%S"))
    for x in range (0,8):
        log.write(",%3.1f" % (get_temperature(x)))
    log.write(strftime("\n"))
    log.close()
    time.sleep(5)'''

class Myframe(wx.Frame):

    def Close(self, event):
        dialog=wx.MessageDialog(self, 'For sure?', 'End work',  style=wx.OK | wx.CANCEL)
        x=dialog.ShowModal()
        dialog.Destroy()
        if x == wx.ID_OK:
            self.Close()


    def __init__(self):
        wx.Frame.__init__(self, None, wx.ID_ANY, "Temperature Monitoring", size=(1024,760))
        panel = wx.Panel(self, wx.ID_ANY)
        self.index = 0


        MenuListwa=wx.MenuBar()
        ProgMenu=wx.Menu()
        ProgMenuItem1=ProgMenu.Append(wx.ID_ANY,'Temperature','Read data')
        self.Bind(wx.EVT_MENU, self.OpenData, ProgMenuItem1)
        MenuListwa.Append(ProgMenu,'Data')

        ProgMenu=wx.Menu()
        ProgMenuItem1=ProgMenu.Append(wx.ID_EXIT, 'End', 'End program')
        MenuListwa.Append(ProgMenu, 'Exit')
        self.Bind(wx.EVT_MENU, self.Close, ProgMenuItem1)
        self.SetMenuBar(MenuListwa)


        self.list_ctrl = wx.ListCtrl(panel, size=(-1,600),
                         style=wx.LC_REPORT
                         |wx.BORDER_SUNKEN
                         )
        self.list_ctrl.InsertColumn(0, 'Record', width=100)
        self.list_ctrl.InsertColumn(1, 'Temperature', width=800)

        btn = wx.Button(panel, label='Add record')
        btn.Bind(wx.EVT_BUTTON, self.onStartTimer)

        self.timer = wx.Timer(self, wx.ID_ANY)
        self.Bind(wx.EVT_TIMER, self.add_records, self.timer)

        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.list_ctrl, 0, wx.ALL|wx.EXPAND, 5)
        sizer.Add(btn, 0, wx.ALL|wx.CENTER, 5)
        panel.SetSizer(sizer)

def onStartTimer(self, event):
        print 'rekordy'
        self.timer.Start(10)

def add_records(self, event):
    while True:
        Temp=[]
        for ch in range(0,8):
            Temp.append(get_temperature(ch))
        line = "Record %s" % self.index
        self.list_ctrl.InsertStringItem(self.index, line)
        add1 = self.list_ctrl.SetStringItem(self.index, 1, Temp[self.index])
        for i in Temp:
            add1 += self.list_ctrl.SetStringItem(self.index, 1, Temp[self.index])
        self.index += 1
        time.sleep(30)


# Run
if __name__ == "__main__":
    app = wx.App(False)         
    frame = Myframe()
    frame.Show()
    frame.Update()
    app.MainLoop()

snippet:

def onStartTimer(self, event):
    print 'records'
    self.timer.Start(10)
    time.sleep(10)

def add_record(self, event):
    while True:           
        for ch in range(0,8):
            Temp.append(get_temperature(ch))
        line = "Record %s" % self.index
        self.list_ctrl.InsertStringItem(self.index, line)
        add1 = self.list_ctrl.SetStringItem(self.index, 1, str(Temp[self.index]))
        for i in Temp:
            add1 += self.list_ctrl.SetStringItem(self.index, 1, str(Temp[self.index]))
        self.index += 1

Answer 1

you need to create a wx.Timer and bind it to an event that will update your list control, add this to the end of the frame's init method

TIMER_ID = wx.NewId()
self.timer = wx.Timer(id=TIMER_ID)
self.Bind(wx.EVT_TIMER, self.on_timer, id=TIMER_ID)
self.timer.Start(10*1000)


def on_timer(self, event):
    self.add_records()


def add_records(self):
    for ch in range(0, 8):
        temp = get_temperature(ch)
        line = "Record %s" % self.index
        self.list_ctrl.InsertStringItem(self.index, line)
        self.list_ctrl.SetStringItem(self.index, 1, temp)
        self.index += 1